Alpha Ophiuchi

Alpha Ophiuchi (α Ophiuchi, abbreviated Alpha Oph, α Oph), also named Rasalhague , is a binary star and the brightest star in the constellation of Ophiuchus.
Nomenclature.
The name Alpha Ophiuchi is a Romanisation of the star's Bayer designation, "α Ophiuchi". It is also known by the traditional name "Rasalhague", from the Arabic رأس الحواء "raʼs al-ḥawwāʼ" "the head of the serpent collector". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two collections of approved names, formally listing Alpha Ophiuchi as "Rasalhague".
Properties.
Alpha Ophiuchi is a binary star system with an orbital period of about 8.62 years. The orbital parameters were only poorly known until 2011 when observations using adaptive optics produced a better orbital fit, allowing the individual masses of the two components to be determined. The primary component, Alpha Ophiuchi A, has a mass of about 2.4 times the mass of the Sun, while the secondary, Alpha Ophiuchi B, has 0.85 solar masses. Estimates of the mass of the primary by other means range from a low of 1.92 to 2.10 solar masses, up to 2.84 or even 4.8 solar masses. The mass of the secondary suggests that it has a stellar classification in the range K5V to K7V, which indicates it is a main sequence star that is still generating energy by the thermonuclear fusion of hydrogen at its core. The pair reached periastron passage, or closest approach, around April 19, 2012, when they had an angular separation of 50 milliarcseconds.
This star system has a combined apparent magnitude of +2.08 and is located at a distance of about from the Earth. The stellar classification of A5 III indicates that the primary is a giant star that has evolved away from the main sequence after consuming the hydrogen at its core. It is radiating about 25 times the luminosity of the Sun and has an effective temperature of about 8,000 K, giving it the characteristic white hue of an A-type star.
The spectrum of Alpha Ophiuchi shows an anomalously high level of absorption of the lines for singly-ionized calcium (Ca II). However, this is likely the result of interstellar matter between the Earth and the star, rather than a property of the star or circumstellar dust.
Rotation.
Alpha Ophiuchi A is a rapidly rotating star with a projected rotational velocity of 240 km s−1. It is spinning at about 88.5% of the rate that would cause the star to break up. This gives it an oblate spheroid shape with an equatorial bulge about 20% larger than the polar radius. The polar radius is calculated to be and the equatorial radius .
Because of the oblateness and rapid spin, the surface gravity at the pole is higher than at the equator. An effect known as gravity darkening means that the temperature at the poles is also higher than at the equator. The polar temperature is calculated to be and the equatorial temperature .
The energy radiated by an oblate star is higher along its axis of rotation because of the larger projected area and the Stefan–Boltzmann law. The axis of rotation of α Ophiuchi is inclined about to the line of sight from the Earth, so that it is being observed from nearly equator-on. The apparent bolometric luminosity seen at this angle is , but the true luminosity of the star is thought to be . Since a star's effective temperature is simply the temperature which would produce its total energy output from a black body, the true effective temperature of is different from the apparent effective temperature of .


Upsilon Herculis

Upsilon Herculis (υ Her) is a solitary star in the constellation Hercules. It is visible to the naked eye with an apparent visual magnitude of 4.74. Based upon an annual parallax shift of 8.78 mas as seen from Earth, it is located around 371 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.09 due to interstellar dust.
At an estimated age of 254 million years, this appears to be an evolved B-type giant star with a stellar classification of B9 III. It is a mercury-manganese chemically peculiar star, indicating the spectrum shows abnormal abundances of these elements. The star has about four times the radius of the Sun and it radiates 173 times the Sun's luminosity from its photosphere at an effective temperature of 10,152 K.


3C 433

3C 433 is a Seyfert galaxy located in the constellation Vulpecula.


Alpha Telescopii

Alpha Telescopii, Latinized from α Telescopii, is the brightest star in the southern constellation of Telescopium, with an apparent visual magnitude of 3.5. The ancient Roman astronomer Ptolemy included it in the constellation Corona Australis, but it was moved to Telescopium when that constellation was created by French astronomer Nicolas Louis de Lacaille in the 18th century. Parallax measurements put it at a distance of from Earth. At that range, the visual magnitude of the star is diminished by an extinction of 0.22 due to interstellar dust.
Properties.
Physical Characteristics.
This star is much larger than the Sun, with an estimated times the mass and times the radius. The spectrum of the star matches a stellar classification of B3 IV, where the luminosity class of 'IV' indicates this is a subgiant star that has nearly exhausted the supply of hydrogen at its core and is evolving away from the main sequence. Alpha Telescopii is a bright star that is radiating nearly 800 times the Sun's luminosity. This energy is being emitted from the star's outer envelope at an effective temperature of around 16,700 K, giving it the characteristic blue-white hue of a B-type star.
Variability.
This is possibly a type of variable star known as a slowly pulsating B-type star. It has a longitudinal magnetic field with a mean strength of . A projected stellar rotation velocity of about 14 km s−1 is considered low for a star of this type, which may indicate it is being viewed from nearly pole-on.


R Horologii

R Horologii is a red giant star approximately 1,000 light-years away in the southern constellation of Horologium. It is a Mira variable with a period of 404.83 days, ranging from apparent magnitude 4.7 to 14.3—one of the largest ranges in brightness known of stars in the night sky visible to the unaided eye. The star is losing mass at the rate of .


LY Aurigae

LY Aurigae is a multiple star system in the constellation Auriga. It is an eclipsing binary variable star, dropping in brightness by 0.7 magnitudes every 4 days. The system is around a thousand light years away in the Auriga OB1 stellar association.
System.
LY Aurigae is a close visual binary. The two stars are magnitude 6.85 and magnitude 8.35 0.6 arc-seconds apart. Each star is also a spectroscopic binary.
LY Aur A is a double-lined spectroscopic binary with an O9 bright giant and an O9 giant star in contact and eclipsing each other as they orbit every 4 days. It is classified as a Beta Lyr eclipsing variable system. The primary eclipse is 0.69 magnitudes deep and the secondary eclipse is 0.60 magnitudes. Because of the contact nature of the system and the deformed shapes of the stars, the magnitude varies constantly throughout the orbital cycle. The orbital period is slowly changing due to mass exchange between the stars. Each star is over a hundred thousand times the luminosity of the sun.
LY Aur B is a single-lined spectroscopic binary with an orbital period of 20.5 days. It is probably an early B main sequence star and the companion is undetectable. The two stars combined are 47,000 times the luminosity of the sun.


79 Cancri

79 Cancri is a star in the constellation Cancer, located 400 light years from the Sun. It is just visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 6.04. This object is gradually moving slower to the Earth with a heliocentric radial velocity of −3.2 km/s.
This is an aging giant star with a stellar classification of G5 III, which indicates that, at the age of 770 million years, it has exhausted the hydrogen at its core and evolved away from the main sequence. The star has 2.30 times the mass of the Sun and has expanded to 9.4 times the Sun's radius. It is radiating 58 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 5,076 K.


I Carinae

The Bayer designations i Carinae and I Carinae are distinct (lower and upper case i) and refer to stars/star systems of apparent magnitude 3.96 and 3.99 respectively.


NGC 3666

NGC 3666 is an unbarred spiral galaxy in the constellation Leo. It was discovered by William Herschel on March 15, 1784.


EZ Canis Majoris

EZ Canis Majoris (abbreviated to EZ CMa, also designated as WR 6) is binary system in the constellation of Canis Major. The primary is a Wolf-Rayet star and it is one of the ten brightest Wolf-Rayet stars, brighter than apparent magnitude 7.
Binary system.
EZ CMa has an apparent visual magnitude which varies between 6.71 and 6.95 over a period of 3.766 days, along with changes in the spectrum. It has been proposed that it could be a binary star, with a neutron star as companion that would complete an orbit around the Wolf-Rayet with that period, being it the cause of those variations. The General Catalogue of Variable Stars lists it as a possible cataclysmic variable on this basis. It has been argued that the companion does not exist and spectral variations are caused by activity on the star's surface.
Observations of the light variations over a four-month period from late 2015 to early 2016 confirmed the clear variations. This was interpreted as a orbital period with rapid apsidal precession completing a full rotation in about 100 days. The orbit is inclined at around 60–74 degrees and there are two eclipses during each orbit.
Wolf Rayet star and nebula.
The spectral type of WN4 indicates an extremely hot star, and this leads to a very high luminosity, mostly emitted as ultraviolet radiation. The spectrum shows a star entirely devoid of hydrogen at the surface.
EZ CMa is surrounded by a faint bubble nebula, a small HII region blown by stellar winds up to 1,700 km/s and ionised by the intense UV radiation. This is catalogued as Sharpless 308 or just S308. It is likely to be a member of the very scattered open cluster Collinder 121, found around the orange supergiant ο1 CMa.


Epsilon Sagittarii

Epsilon Sagittarii (Latinised from ε Sagittarii, abbreviated Epsilon Sgr, ε Sgr), formally named Kaus Australis , is a binary star system in the southern zodiac constellation of Sagittarius. The apparent visual magnitude of +1.85 makes it the brightest object in Sagittarius. Based upon parallax measurements, this star is around from the Sun.
Stellar system.
The primary star, ε Sagittarii A, of this binary star system has a stellar classification of B9.5 III, with the luminosity class of III suggesting this is an evolved giant star that has exhausted the supply of hydrogen at its core. The interferometry-measured angular diameter of this star, after correcting for limb darkening, is , which, at its estimated distance, equates to a physical radius of about 6.8 times the radius of the Sun. This is a close match to the empirically-determined value of 6.9 solar radii. It has about 3.5 times the mass of the Sun and is radiating around 363 times the Sun's luminosity from its outer atmosphere at an effective temperature of 9,960 K. At this heat, the star glows with a blue-white hue.
This star is spinning rapidly with a projected rotational velocity of 236 km s−1. It has a magnetic field with a strength in the range 10.5–130.5 Gauss and it is an X-ray source with a luminosity of about 1030 erg s−1. The system displays an excess emission of infrared radiation, which suggests the presence of a circumstellar disk of dust. Based upon the temperature of this disk, it is orbiting at a mean separation of 155 AU from the primary.
As of 2001, the secondary star, ε Sagittarii B, is located at an angular separation of 2.392 arcseconds from the primary along a position angle of 142.3°. At the distance of this system, this angle is equivalent to a physical separation of about 106 AU, which places it inside the debris disk. It is a main sequence star with about 95% of the mass of the Sun. The system has a higher optical linear polarisation than expected for its distance from the Sun; this has been attributed to light scattered off the disk from the secondary. Prior to its 1993 identification using an adaptive optics coronagraph, this companion may have been responsible for the spectral anomalies that were attributed to the primary star. There is a candidate stellar companion at an angular separation of 32.3 arcseconds.
Nomenclature.
"ε Sagittarii" (Latinised to "Epsilon Sagittarii") is the star system's Bayer designation.
It bore the traditional name "Kaus Australis", which derived from the Arabic قوس "qaws" 'bow' and Latin "austrālis" 'southern'. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included "Kaus Australis" for the star ε Sagittarii A.
In the catalogue of stars in the "Calendarium" of Al Achsasi al Mouakket, this star was designated "Thalath al Waridah", or "Thalith al Waridah", meaning 'third of Warida'.
In Chinese, (), meaning "Winnowing Basket", refers to an asterism consisting of Epsilon Sagittarii, Gamma Sagittarii, Delta Sagittarii and Eta Sagittarii. Consequently, the Chinese name for Epsilon Sagittarii itself is (, .)
This star, together with:
Kaus Australis is listed in the Babylonian compendium MUL.APIN as MA.GUR8, meaning "the Bark".
The Kalapalo people of Mato Grosso state in Brazil called this star and λ Scorpii, through ι Scorpii, θ Scorpii, ν Scorpii, υ Scorpii and ρ Scorpii "Taugi kusugu", "Taugi's fishing basket".
References.
\end{align}</math></ref>


NGC 509

NGC 509 is a lenticular galaxy approximately 87 million light-years away from Earth in the constellation of Pisces. It was discovered by German astronomer Albert Marth on October 1, 1864.


Mu Ursae Majoris

Mu Ursae Majoris (μ Ursae Majoris, abbreviated Mu UMa, μ UMa), formally named Tania Australis , is a binary star in the constellation of Ursa Major. An apparent visual magnitude of +3.06 places it among the brighter members of the constellation. Parallax measurements give an estimated distance of roughly from the Sun, with a margin of error of 4%.
Stellar system.
Mu Ursae Majoris is an evolved star that is currently in the red giant stage with a stellar classification of M0 IIIab. It has expanded to 75 times the radius of the Sun whilst the outer atmosphere has cooled to an effective temperature of 3,899 K, giving it the orange-red hued glow of an M-type star. Estimates of the luminosity range from 977–1,200 times that of the Sun. It is classified as a suspected variable star with a brightness variation from magnitude 2.99m to 3.33m.
This is a spectroscopic binary star system with a companion a mere 0.2 AU from the primary, assuming a distance of 71 parsecs, with an orbital period of 230 days.
Nomenclature.
"μ Ursae Majoris" (Latinised to "Mu Ursae Majoris") is the star's Bayer designation.
It bore the traditional names "Tania" (shared with Lambda Ursae Majoris) and "Tania Australis". "Tania" comes from the Arabic phrase 'the Second Spring (of the Gazelle)'. and "Australis" (originally "australis") is Latin for 'the south side'. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included "Tania Australis" for this star.
In Chinese, (), meaning "Three Steps", refers to an asterism consisting of Mu Ursae Majoris, Iota Ursae Majoris, Kappa Ursae Majoris, Lambda Ursae Majoris, Nu Ursae Majoris and Xi Ursae Majoris. Consequently, the Chinese name for Mu Ursae Majoris itself is (, ).


NGC 500

NGC 500 (also known as PGC 5013) is a type E-SO lenticular galaxy located in the Pisces constellation. It has an apparent size of .8 by .6 arcminutes and an apparent magnitude of 14.2. It was first discovered in 1850 by Bindon Blood Stoney during his time at Birr Castle in Ireland.


NGC 6535

NGC 6535 is a globular cluster of stars located at a distance of 22,200 light years from Earth in the equatorial constellation of Serpens, and is listed in the "New General Catalogue". Its discovery is usually attributed to astronomer John Russell Hind in 1852, however Wolfgang Steinicke has uncovered evidence that William Herschel's first discovery was actually NGC 6535, which he observed on 24th August 1780.
The cluster is suspected to harbour an intermediate-mass black hole in its center and, unusually for a low-mass globular cluster, has had multiple generations of stars.


Omega Scorpii

There are two stars with the Bayer designation ω Scorpii (omega Scorpii):
They are separated by 0.24° on the sky, which is far enough apart to be individually resolved with the naked eye. The two stars are not physically associated with each other, and thus only form an optical pair. ω Scorpii also has the traditional name Jabhat al Akrab, which is derived from the Arabic جبهة العقرب "jabhat[u] al-caqrab" meaning "[The] forehead of the scorpion". For the Chinese, the pair were known as "Kow Kin", meaning a Hook and Latch.


Omega Leonis

ω Leonis (Latinised as Omega Leonis, abbreviated to ω Leo or Omega Leo), is a star located in the zodiac constellation of Leo. It is visible to the naked eye in the absence of light pollution, with an apparent visual magnitude of about 5.4. The distance to this star, as determined using parallax measurements, is around 108 light years from the Sun. Because of its location close to the ecliptic, it is subject to being obscured by the Moon, and potentially by planets.
This is a spectroscopic binary star system with an orbital period of 116.8 years and an eccentricity of 0.56. In 2010, speckle interferometry observations showed an angular separation of between the two components along a position angle of . The primary is a G-type main sequence star with a spectral classification of G1 V. It has about 35% more mass than the Sun and shines six times as brightly from an outer atmosphere that has an effective temperature of 5940 K. The system is roughly 3.7 billion years old and is a member of the galactic thin disk population.


AB Pictoris b


M2-9

Minkowski 2-9, abbreviated M2-9 (also known as Minkowski's Butterfly, Twin Jet Nebula, the Wings of a Butterfly Nebula, or just Butterfly Nebula) is a planetary nebula that was discovered by Rudolph Minkowski in 1947. It is located about 2,100 light-years away from Earth in the direction of the constellation Ophiuchus. This bipolar nebula takes the peculiar form of twin lobes of material that emanate from a central star. Astronomers have dubbed this object as the "Twin Jet Nebula" because of the jets believed to cause the shape of the lobes. Its form also resembles the wings of a butterfly. The nebula was imaged by the Hubble Space Telescope in the 1990s.
The primary component of the central binary is the hot core of a star that reached the end of its main-sequence life cycle, ejected most of its outer layers and became a red giant, and is now contracting into a white dwarf. It is believed to have been a sun-like star early in its life. The second, smaller star of the binary orbits very closely and may even have been engulfed by the other's expanding stellar atmosphere with the resulting interaction creating the nebula. Astronomers theorize that the gravity of one star pulls some of the gas from the surface of the other and flings it into a thin, dense disk extending into space.
The nebula has inflated dramatically due to a fast stellar wind, blowing out into the surrounding disk and inflating the large, wispy hourglass-shaped wings perpendicular to the disk. These wings produce the butterfly appearance when seen in projection. The outer shell is estimated to be about 1,200 years old .


Kepler-65

Kepler-65 is a star slightly more massive than the Sun and has at least four planets.
Planetary system.
Three transiting planets were announced in 2013. A fourth non-transiting planet was discovered using radial velocity measurements in 2019. The first three planets orbit very close to their star. Initial follow-up radial velocity measurements provided data too noisy to constrain the mass of planets. Follow-up transit-timing variation analysis helped to measure the mass of Kepler-65d which revealed that it has significantly lower density than Earth.


V337 Carinae

V337 Carinae (V337 Car, q Carinae) is a K-type bright giant star in the constellation of Carina. It is an irregular variable and has an apparent visual magnitude which varies between 3.36 and 3.44.
V337 has a spectral class of K2.5II, indicating a bright giant. It is considered likely to be on the red giant branch of stars fusing hydrogen around an inert helium core. Its limb-darkened angular diameter has been measured using interferometry at .
V337 Carinae has two companions listed in multiple star catalogues. Both are 13th-magnitude stars, component B and component C away. Component B is a distant background star, while component C is at about the same distance as V337 Carinae.


List of stars in Corona Australis

This is the list of notable stars in the constellation Corona Australis, sorted by decreasing brightness.


59 Leonis

59 Leonis, or c Leonis, is a single white-hued star in the southern part of the constellation of Leo. It is north of 58 Leonis, south of Chi Leonis, and well east of the bright star Regulus. Its apparent visual magnitude is 4.98, so it is dimly visible to the naked eye, 0.21 degree south of the ecliptic. The annual parallax shift as seen from Earth's orbit is , giving a distance estimate of about 151 light years. The star is moving closer to the Sun with a heliocentric radial velocity of −12 km/s.
Cowley et al. (1969) assigned 59 Leonis a stellar classification of A5 III, matching the spectrum of an A-type giant star, but Gray and Garrison (1989) found a class of A6 IV, suggesting it is a subgiant star. Hauck (1986) noted that the star is classified as a giant, but the colors match a dwarf star and it had been previously classified as F3 V. It is an estimated 332 million years old with a high rate of spin, showing a projected rotational velocity of 82 km/s. The star has around 1.73 times the mass of the Sun and is radiating 18 times the Sun's luminosity from its photosphere at an effective temperature of about 8,277 K.


Mother Camels

The protecting Mother Camels (Arabic العوائذ "alʽawaʼid") is an asterism in the constellation of Draco described by ancient Arabic nomadic tribes. The asterism was interpreted as a ring of mother camels – Beta Draconis (Rastaban), Gamma Draconis (Eltanin), Nu Draconis (Kuma) and Xi Draconis (Grumium) – surrounding a foal (the faint star Alruba), with another mother camel, Mu Draconis (Alrakis) running to join them.
The Arabs did not see the constellation Draco as it is now. The Mother Camels were protecting the foal from the attack of two wolves or jackals – Zeta Draconis (Aldhibah) and Eta Draconis (Athebyne). The faint pair Omega Draconis and 27 Draconis was known as the "wolf's claws" (الأظفار الذئب "al-ʼaẓfār al-dhiʼb").


Beta Coronae Borealis

Beta Coronae Borealis (β Coronae Borealis, abbreviated Beta CrB, β CrB) is a binary star in the constellation of Corona Borealis. It appears to the naked eye to be a single star and is the second-brightest star in its constellation with an apparent visual magnitude varying between 3.65 and 3.72. Based on parallax measurements taken during the Hipparcos mission, it is approximately 112 light-years from the Sun.
The two components are designated Beta Coronae Borealis A (officially named Nusakan , the traditional name of the system) and B
Nomenclature.
"β Coronae Borealis" (Latinised to "Beta Coronae Borealis") is the system's Bayer designation. The designations of the two components as "Beta Coronae Borealis A" and "B" derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).
It bore the traditional name "Nusakan", from Arabic النسقان "al-nasaqān" "the two lines [of stars]", originally a pair of asterisms - a northern line mostly in Hercules, and a southern line in Serpens and Ophiuchus.
In 2016, the IAU organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name "Nusakan" for the component Beta Coronae Borealis A on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.
In Chinese, (), meaning "Coiled Thong", refers to an asterism consisting of Beta Coronae Borealis, Pi Coronae Borealis, Theta Coronae Borealis, Alpha Coronae Borealis, Gamma Coronae Borealis, Delta Coronae Borealis, Epsilon Coronae Borealis, Iota Coronae Borealis and Rho Coronae Borealis. Consequently, the Chinese name for Beta Coronae Borealis itself is (, ).
Properties.
Beta Coronae Borealis was first announced to be a binary star in 1907, based on spectroscopic observations at Lick Observatory; J. B. Cannon published an orbit in 1914, finding a period of 40.9 days. Later spectroscopic investigations by F. J. Neubauer at Lick, published in 1944, found a period of 10.5 years, with no evidence for the 41-day periodicity. Antoine Labeyrie and his coworkers resolved the pair by speckle interferometry in 1973 and found that the two stars were separated by about 0.25 arcseconds; this work was published in 1974. The pair was also observed visually by Coteau in 1973. A number of orbits were subsequently published using visual and speckle-interferometric observations, both alone and in conjunction with spectroscopic data. In 1999, Söderhjelm published an orbit using speckle-interferometric data together with Hipparcos observations.
Neubauer's 1944 work found a small variation in the radial velocity of Beta Coronae Borealis with a periodicity of 320 days, suggesting the presence of a third, lighter, body in the system. A 1999 study of the system by long-baseline infrared interferometry performed at Palomar Observatory found no evidence for this, and showed that any tertiary companion with this period must have mass 10 Jupiter masses or below. This study also found very weak evidence for the presence of a companion with a shorter, 21-day, period, but the data was insufficient to draw a positive conclusion.
The brighter component, Beta Coronae Borealis A, is a Rapidly oscillating Ap star, with a period of 16.2 minutes. Of spectral type A5V with a surface temperature of around 7980 K, it has around 2.09 times the mass of the Sun, 2.63 times its radius and 25.3 times its luminosity. The smaller star is a main sequence star with spectral type F2, a surface temperature of around 6750 K, around 1.4 times the mass of the Sun, 1.56 times its radius, and between 4 and 5 times its luminosity. The system is around 530 million years old.


35 Comae Berenices

35 Comae Berenices is a multiple star system in the northern constellation of Coma Berenices, located about 6° from the north galactic pole. It is faintly visible to the naked eye with an apparent visual magnitude of 4.93. Based upon parallax measurements, it is located around 280 light years from the Sun. The system is moving closer to the Earth with a heliocentric radial velocity of −6 km/s.
This was found to be a wide binary by Struve in 1828, but it has completed less than half an orbit since then and the orbital elements remain poorly constrained. It has an orbital period of and an eccentricity of . The pair have been resolved into stellar classifications of an evolved G-type giant primary of class G5 III and an F-type secondary, most likely main sequence with a class of F1 V. The primary component is a spectroscopic binary with a period of and an eccentricity of 0.63. A fourth component, 35 Com C, is located from the primary and may have a physical association.


Epsilon Draconis

Epsilon Draconis (ε Dra, ε Draconis) is a fourth-magnitude star in the constellation Draco. This star along with Delta Draconis (Altais), Pi Draconis and Rho Draconis forms an asterism known as Al Tāis, meaning "the Goat".
In Chinese astronomy, (), meaning the Celestial Kitchen, refers to an asterism consisting of Epsilon Draconis, Delta Draconis, Sigma Draconis, Rho Draconis, 64 Draconis and Pi Draconis. Consequently, the Chinese name for Epsilon Draconis itself is (, .) Most authors do not use a traditional name for this star, using instead the Bayer designation;
but Bečvář (1951) listed it as Tyl .
Visibility.
With a declination in excess of 70 degrees north, Epsilon Draconis is principally visible in the northern hemisphere, with southern locations north of 20° South able to see it just above the horizon. The star is circumpolar throughout all of Europe, China, most of India and as far south as the tip of the Baja peninsula in North America as well as other locations around the globe having a latitude greater than ± 20° North. Since Epsilon Draconis has an apparent magnitude of almost 4.0, the star is easily observable to the naked eye as long as one's stargazing is not hampered by the light pollution common to most cities.
The best time for observation is in the evening sky during the summer months, when the "Dragon constellation" passes the meridian at midnight, but given its circumpolar nature in the northern hemisphere, it is visible to most of the world's inhabitants throughout the year.
Properties.
Epsilon Draconis is a yellow giant star with a spectral type of G8III. It has a radius that has been estimated at 10 solar radii and a mass of 2.7 solar masses. Compared to most G class stars, Epsilon Draconis is a relatively young star with an estimated age of around 500 million years old. Like the majority of giant stars, Epsilon Draconis rotates slowly on its axis with a rotational velocity of 1.2 km/s, a speed which takes the star approximately 420 days to make one complete revolution.
In 2007, Floor van Leeuwen and his team calibrated the star's apparent magnitude at 3.9974 with an updated parallax of 22.04 ± 0.37 milliarcseconds, yielding a distance of 45.4 parsecs or approximately 148 light years from Earth. Given a surface temperature of 5,068 Kelvin, theoretical calculations would yield a total luminosity for the star of about 60 times the solar luminosity.
Star system.
Epsilon Draconis is resolvable as a double star in telescopes of 10 centimeters aperture or larger. The companion has an apparent brightness of 7.3 at an angular distance of 3.2 arcseconds. It is a giant of spectral class F5, orbiting the yellow giant at about 130 astronomical units.


NGC 6286

NGC 6286 is an interacting spiral galaxy located in the constellation Draco. It is designated as Sb/P in the galaxy morphological classification scheme and was discovered by the American astronomer Lewis A. Swift on 13 August 1885. NGC 6286 is located at about 252 million light years away from Earth. NGC 6286 and NGC 6285 form a pair of interacting galaxies, with tidal distortions, categorized as Arp 293 in the Arp Atlas of Peculiar Galaxies.<ref name="NASA/IPAC"></ref>


Mu Coronae Borealis

Mu Coronae Borealis, Latinized from μ Coronae Borealis, is a solitary, ruby-hued star located in the northern constellation of Corona Borealis. It is faintly visible to the naked eye, having an apparent visual magnitude of 5.12. Based upon an annual parallax shift of 5.27 mas, it is located roughly 620 light years from the Sun. This is an evolved red giant star with a stellar classification of M1.5 IIIb. It is currently on the asymptotic giant branch and is a variable star of uncertain type, showing a change in brightness with an amplitude of 0.0147 magnitude and a frequency of 0.02455 cycles per day, or 40.7 days/cycle. On average, it is radiating 932 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,889 K.


NGC 3228

NGC 3228 is an open cluster in Vela. It was discovered by Nicolas Louis de Lacaille in 1751–1752, while he was in South Africa and catalogued it as Lac II.7. It is small but bright and can be observed easily with binoculars in sufficiently dark skies.
It is a cluster of Trumpler type I1p or II3p, with few members with large brightness range and a slight concentration toward its center. Klarchenko et al. mention 53 possible members within the angular diametre of the cluster. The tidal radius of the cluster is 1.4 – 5.5 parsecs (4.5 – 18 light years) and represents the average outer limit of NGC 3228, beyond which a star is unlikely to remain gravitationally bound to the cluster core. The brightest member is of mag. 7.9 and the hottest star is of spectral type B9. One member, HD 89856 (mag. 9.04, spectral type B9), is a variable star with period 4.556 days.


Horn (Chinese constellation)

The Horn mansion (角宿, pinyin: Jiǎo Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the eastern mansions of the Azure Dragon.


RT Normae

RT Normae is an R Coronae Borealis type variable star in the constellation Norma. It has a baseline magnitude of 9.8, dropping down to 14.7 at its minima.
It has less than 55% the mass of the Sun and an effective (surface) temperature of around 7000 K.


Nu Centauri

Nu Centauri (ν Cen, ν Centauri) is a binary star system in the southern constellation of Centaurus. The combined apparent visual magnitude of the pair is +3.41, making this one of the brightest members of the constellation. Based upon parallax measurements made during the Hipparcos mission, this star system is located at a distance of roughly from Earth. The margin of error for this distance is about 2%, which is enough to give an error in distance of ±10 light years.
This is a single-lined spectroscopic binary system, which means that the two stellar components have not been individually resolved with a telescope. Instead, their orbital motion can be tracked through periodic shifts in the spectrum of the primary. The gravitational perturbation of the hidden secondary component upon the primary is causing the latter to first move toward and then away from the Earth, creating Doppler shift changes in the spectrum. From these subtle shifts, the orbital elements of the pair can be extracted. The pair are orbiting their common center of mass in a circular orbit with a period of only 2.622 days, indicating that they are in a relatively tight orbit.
The interaction between the two components of this system appears to be creating emission lines in the spectrum, turning the primary into a Be star. It has a stellar classification of B2 IV, which matches a massive B-type subgiant star. The primary has 8.5 times the mass of the Sun and 6.4 times the Sun's radius. It is a Beta Cephei type variable star with a brightness that periodically varies from magnitude +3.38 to +3.41 over an interval of 0.17 days. The tidal interaction with the secondary component has turned it into a rotating ellipsoidal variable.
This star system is a proper motion member of the Upper-Centaurus Lupus sub-group in the
Scorpius-Centaurus OB association,
the nearest such association of co-moving massive stars to the Sun.


Sigma Scorpii

Sigma Scorpii (or σ Scorpii, abbreviated Sigma Sco or σ Sco), is a multiple star system in the constellation of Scorpius, located near the red supergiant Antares, which outshines it. This system has a combined apparent visual magnitude of +2.88, making it one of the brighter members of the constellation. Based upon parallax measurements made during the Hipparcos mission, the distance to Sigma Scorpii is roughly 696 light-years (214 parsecs). North "et al." (2007) computed a more accurate estimate of  light years ( parsecs).
The system consists of a spectroscopic binary with components designated Sigma Scorpii Aa1 (officially named Alniyat , the traditional name for the entire star system)<ref name="IAU-LSN">


NGC 4030

NGC 4030 is a grand design spiral galaxy located about 64 million light years away in the constellation Virgo. With an apparent visual magnitude of 10.6, it is visible with a small telescope as a 3 arc minute wide feature about 4.75° to the southeast of the star Beta Virginis. It is inclined by an angle of 47.1° to the line of sight from the Earth and is receding at a velocity of 1,465 km/s.
The morphological classification of NGC 4030 in the De Vaucouleurs system is SA(s)bc, which indicates a spiral structure (SA) with no bar (s) and moderate to loosely wound arms (bc). The inner part of the galaxy shows a complex structure with multiple spiral arms, which becomes a symmetric, double arm pattern beyond 49″ from the core. The central bulge is relatively young with an estimated age of two billion years, while the nucleus is inactive.
In 2007, a supernova explosion was discovered in the galaxy from images taken on February 19 from the 1 m Swope telescope at Las Campanas Observatory in Chile. Designated SN 2007aa, it was a type IIP supernova positioned 68″.5 north and 60″.8 east of the galactic nucleus. The progenitor was a red giant star with 8.5–16.5 times the mass of the Sun.


Hairy Head

The Hairy Head mansion (昴宿, pinyin: Mǎo Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the western mansions of the White Tiger.
This mansion corresponds to the Pleiades in English.


EC 20058-5234

EC 20058-5234, also known as QU Telescopii, is a star in the constellation Telescopium. A pulsating white dwarf, it belongs to a class of star known as V777 Herculis variables or DBV stars. First noticed in the Edinburgh-Cape Blue Object Survey published in 1992, it was found to be variable in 1995.


Terzan 7

Terzan 7 is a sparse and young globular cluster that is believed to have originated in the Sagittarius Dwarf Spheroidal Galaxy (Sag DEG) and is physically associated with it. It is relatively metal rich with [Fe/H] = -0.6 and an estimated age of 7.5 Gyr. Terzan 7 has low levels of nickel ([Ni/Fe] = -0.2) which supports its membership in the Sag DEG system since it has a similar chemical signature. It has a rich population of blue stragglers that are strongly concentrated toward the center of Terzan 7. It has an average luminosity distribution of Mv = -5.05. It has a half-light radius (Rh) of 6.5pc.
History.
Terzan 7 was the brightest of six globulars discovered by Turkish-Armenian astronomer Agop Terzan in 1968.
Young globular.
Nearly all globular clusters of the Milky Way's galactic halo formed at the same time (12-15 Gyr). Even the far situated NGC 2419 (~100 kpc from galactic center) has a similar age. This trend also applies to the age of globulars found in the Large Magellanic Cloud and Fornax Dwarf (~140 kpc from galactic center). However, a few globulars seem to be significantly younger than the rest; these include Palomar 1, Palomar 3, Palomar 4, Palomar 12, Palomar 14, Ruprecht 106, IC 4499, Arp 2, Eridanus, Fornax 4, and Terzan 7. In particular, the ones associated with the Sag DEG appear to have formed more recently. The data suggests that all the present outer halo globulars may have originally formed in dwarf spheroidals.
Hierarchical galaxy formation.
Alternatively, a hierarchical galaxy formation model is hypothesized under which a portion, possibly large, of the Milky Way's globular clusters would have originated in the accretion of other dwarf spheroidals like Sag DEG. The best candidate for this idea is Palomar 12.


Root (Chinese constellation)

The Root mansion (氐宿, pinyin: Dī Xiù) is one of the Twenty-eight mansions of the Chinese constellations. It is one of the eastern mansions of the Azure Dragon.


List of stars in Norma

This is the list of notable stars in the constellation Norma, sorted by decreasing brightness.


XO-5b

XO-5b "Makropulos" is an extrasolar planet approximately 910 light years away in the constellation of Lynx. This planet was found by the transit method using the XO Telescope and announced in May 2008. It was also independently discovered by the HATNet Project. The planet has a mass and radius just slightly larger than that of Jupiter. This planet orbits very close to the G-type parent star, as it is typical for transiting planets, classing this as Hot Jupiter. It takes only 4.188 days (or 100.5 hours) to orbit at an orbital distance of 0.0488 AU).
The planet XO-5b is named Makropulos. The name was selected in the NameExoWorlds campaign by the Czech Republic, during the 100th anniversary of the IAU. Makropulos is the name from Karel Čapek's play Věc Makropulos (The Makropulos Affair).
Discovery.
XO-5b was the fifth hot Jupiter transiting planet discovered by the XO Project and was identified as a possible candidate extrasolar planet from two seasons of observations, November 2003 to March 2004 and November 2004 to March 2005. Follow-up photometry was provided by the extended team, a collaboration of professional and amateur astronomers. The team obtained better quality light curves to guide the photometric and spectroscopic follow-up necessary to classify a candidate as an actual planetary companion.
To confirm XO-5b's planetary nature radial velocity observations of XO-5 were made with the high resolution spectrograph on the 11 meter Hobby–Eberly Telescope located at McDonald Observatory, in order to measure the mass of the planet. Commencing on December 7, 2007 a total of ten radial velocity measurements were made which confirmed XO-5b's status as a planet.


NGC 5822

NGC 5822 is an open cluster in the constellation Lupus.


Alpha Microscopii

Alpha Microscopii (α Microscopii) is a star in the southern constellation of Microscopium. It is visible to the naked eye with an apparent visual magnitude that varies between 4.88 and 4.94. Based upon an annual parallax shift of 8.2214 mas as seen from the Earth, it is located 400 ± 30 light years from the Sun. The star is moving nearer to the Sun with a radial velocity of −15 km/s.
This is an evolved giant star of type G with a stellar classification of G7 III. At the age of 360 million years, it has an estimated 3.1 times the mass of the Sun and has expanded to around 16 times the Sun's radius. The star is radiating 160 times the Sun's luminosity from its expanded photosphere at an effective temperature of 4,923 K.
This star has an optical visual companion, CCDM J20500-3347B, of apparent visual magnitude 10.0 approximately 20.4 arcseconds away at a position angle of 166°. It has no physical connection to the star described above.


Zeta Normae

Zeta Normae, Latinised from ζ Normae, is a solitary, yellow-white hued star in the southern constellation of Norma. With an apparent visual magnitude of 5.81, it is a dim star near the lower limit of visibility for the naked eye. Based upon an annual parallax shift of 14.98 mas as seen from Earth, this system is located about 215 light years from the Sun. It is advancing in the general direction of the Sun with a radial velocity of −45.6 km/s.
This is an evolved F-type giant star with a stellar classification of F2 III that has swollen and cooled off the main sequence after consuming the hydrogen at its core. It is an estimated 1.5 billion years old with 1.74 times the mass of the Sun. Zeta Normae is radiating approximately 16 times the Sun's luminosity from its photosphere at an effective temperature of 6,691 K.


NGC 5753

NGC 5753 is a spiral galaxy in the constellation Boötes. This is a member of the Arp 297 interacting galaxies group of four: NGC 5752, NGC 5753, NGC 5754, NGC 5755.


Gamma Herculis

Gamma Herculis, Latinized from γ Herculis, is a magnitude 3.74 binary star system in the northern constellation of Hercules.
Properties.
This is known to be a spectroscopic binary system, although there is no information about the secondary component. Based upon parallax measurements, this system is located at a distance of about from the Earth. The spectrum of the primary star matches a stellar classification of A9III, which indicates this is a giant star that has exhausted the hydrogen at its core and evolved away from the main sequence. The effective temperature is about 7,031 K, giving the star a white hue characteristic of A-type stars. It is rotating rapidly with a projected rotational velocity of . The interferometry-measured angular diameter of this star is , which, at its estimated distance, equates to a physical radius of about six times the radius of the Sun.
Observations by German astronomer Ernst Zinner in 1929 gave indications that this may be a variable star. It was listed in the "New Catalogue of Suspected Variable Stars" (1981) with a magnitude range of 3.74 to 3.81. Further observations up to 1991 showed a pattern of small, slow variations with a magnitude variation of 0.05. These appeared to repeat semi-regularly with a period of 183.6 days, although the spectroscopic data presented a longer period of 165.9 days.
Name.
It was a member of indigenous Arabic asterism "al-Nasaq al-Sha'āmī", "the Northern Line" of "al-Nasaqān" "the Two Lines", along with β Her (Kornephoros), γ Ser (Zheng, Ching) and β Ser (Chow).
According to the catalogue of stars in the "Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars", "al-Nasaq al-Sha'āmī" or "Nasak Shamiya" were the title for three stars :β Ser as "Nasak Shamiya I", γ Ser as "Nasak Shamiya II", γ Her as "Nasak Shamiya III" (exclude β Her)
In Chinese, (), meaning "Right Wall of Heavenly Market Enclosure", refers to an asterism which is represent eleven old states in China which is marking the right borderline of the enclosure, consisting of γ Herculis, β Herculis, κ Herculis, γ Serpentis, β Serpentis, δ Serpentis, α Serpentis, ε Serpentis, δ Ophiuchi, ε Ophiuchi and ζ Ophiuchi. Consequently, the Chinese name for γ Herculis itself is (, ), represent "Héjiān" (河間), possibly Hejian Kingdom or Hejian Commandery (see Sima Yong, the Prince of Hejian and Liu Wuzhou). "Héjiān" (河間) was westernized into "Ho Keen" by R.H. Allen, which was the meaning "between the river".
References.
\end{align}</math></ref>


NGC 3370

NGC 3370 (also known as UGC 5887 or Silverado Galaxy) is a spiral galaxy about 98 million light-years away in the constellation Leo. It is comparable to our own Milky Way both in diameter (100,000 light years) and mass (1011 solar masses). NGC 3370 exhibits an intricate spiral arm structure surrounding a poorly defined nucleus.
History.
NGC 3370 was likely discovered by William Herschel, who provided it with the designation II 81. His son John later designated it 750. William Herschel cataloged I 80 to NGC 3348 before and II 82 to NGC 3455 after NGC 3370.
The object has a surface brightness of 13 and a position angle (PA) of 140°.
On November 14, 1994, S. Van Dyk and the Leuschner Observatory Supernova Search discovered a supernova in NGC 3370 at 10h 44m 21.52s +17° 32′ 20.7′′, designated SN 1994ae. SN 1994ae was a type Ia supernova, and one of the nearest and best observed since the advent of modern digital detectors. The maximal light of the supernova was estimated to have occurred between November 30 and December 1, peaking at visual magnitude 13.


NGC 4420

NGC 4420 is an unbarred spiral galaxy located 77 million light-years away in the constellation Virgo.


60 Arietis

60 Arietis is a star in the northern constellation of Aries. "60 Arietis" is the Flamsteed designation. It has an apparent visual magnitude of 6.14, making it a challenge to view with the naked eye. Based upon an annual parallax shift of , this star is located away from the Sun. It is receding from the Earth with a heliocentric radial velocity of +24 km/s.
This object is an aging giant star with a stellar classification of K3 III, having exhausted the supply of hydrogen at its core and expanded to 11 times the Sun's radius. It is 5.3 billion years old with 1.36 times the mass of the Sun. The star shines with 49 times the Sun's luminosity; this energy is being radiated from the photosphere at an effective temperature of 4,449 K, giving it the orange-hued glow of a K-type star.


57 Aquilae

57 Aquilae (abbreviated 57 Aql) is a double star in the constellation of Aquila. "57 Aquilae" is its Flamsteed designation. The primary star has an apparent visual magnitude of 5.70, while the secondary is magnitude 6.48. The pair have an angular separation of 35.624 arcseconds and probably form a wide binary star system. The estimated distance of the first component is , while the second is at . However, the margin of errors for their respective distance estimates overlap, indicating a probability that they are actually located much closer to each other. Both stars are massive, B-type main sequence stars with rapid rotation rates.


NGC 2903

NGC 2903 is an isolated barred spiral galaxy in the equatorial constellation of Leo, positioned about 1.5° due south of Lambda Leonis. It was discovered by German-born astronomer William Herschel, who cataloged it on November 16, 1784. He mistook it as a double nebula, as did subsequent observers, and it wasn't until the nineteenth century that the Third Earl of Rosse resolved into a spiral form. J. L. E. Dreyer assigned it the identifiers 2903 and 2905 in his "New General Catalogue"; NGC 2905 now designates a luminous knot in the northeastern spiral arm.
This field galaxy is located about 30 million light-years away from the Milky Way, and is a member of the Virgo Supercluster. The morphological classification of this galaxy is SBbc, indicating a barred spiral (SB) with moderate to tightly-wound spiral arms (bc). De Vaucouleurs and associates assigned it the class SAB(rs)bc, suggesting a weaker bar structure (SAB) with a partial ring (rs). The bar structure appears stronger in the near infrared band. The galaxy as a whole is inclined by an angle of 60° to the line of sight from the Earth.
72% of the stellar mass is located in the outer disk of the galaxy, and 20% is found in the bar. The bulge adds 5% of the stellar mass, and its star population is generally older. However, the central radius volume of the core is a strong starburst region. The star formation rate here is  y−1 and it is being fed by gas inflow along the bar. There is no evidence of an active nucleus.
The irregular dwarf galaxy KKH 51 appears to be a companion, as they have an angular separation of and nearly the same radial velocity.


Markarian 50

Markarian 50 is an open cluster in the Milky Way galaxy. It is about 3,460 pc away in the constellation Cassiopeia. Markarian 50 is a very young open cluster, only about 7.5 million years old. Markarian 50 may be a member of the OB association Cassiopeia OB2. The Wolf-Rayet star WR 157 is a member of Markarian 50.


NGC 7773

NGC 7773 is a barred spiral galaxy located in the constellation of Pegasus at an approximate distance of 400 million light years. NGC 7773 was discovered on October 9, 1790 by William Herschel.


NGC 7066

NGC 7066 is a spiral galaxy located about 210 million light-years away in the constellation of Pegasus. NGC 7066 was discovered by astronomer Lewis Swift on August 31, 1886.


List of stars in Antlia

This is the list of notable stars in the constellation Antlia, sorted by decreasing brightness.


PKS 2000-330

PKS 2000-330 (also known as QSO B2000-330) is a quasar located in the constellation Sagittarius. When identified in 1982, it was the most distant and most luminous object known.
Distance measurements.
The "distance" of a far away galaxy depends on what distance measurement you use. With a redshift of 3.77, light from this active galaxy is estimated to have taken around 11.7 billion years to reach us. But since this galaxy is receding from Earth at an estimated rate of 274,681 km/s (the speed of light is 299,792 km/s), the present (co-moving) distance to this galaxy is estimated to be around 22.7 billion light-years (6947 Mpc).


Zeta Coronae Australis

Zeta Coronae Australis (ζ Coronae Australis) is a solitary, blue-white hued star located in the southern constellation Corona Australis. With an apparent visual magnitude of +4.75, it is sufficiently bright to be viewed with the naked eye. Based upon an annual parallax shift of 16.89 mas as seen from Earth, this star is located around 193 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction of 0.15 due to interstellar dust.
This is a B-type main sequence star with a stellar classification of B9.5 Vann. The suffix notation 'nn' indicates there are broad spectrum absorption lines in the spectrum associated with its rotation period. At the estimated age of just 76 million years, it is spinning rapidly with a projected rotational velocity of 308 km/s. The star has 2.92 times the mass of the Sun and 2.11 times the Sun's radius. It is radiating 51 times the Sun's luminosity from its photosphere at an effective temperature of about 12,039 K.
There is an infrared excess at a wavelength of 60 μm. This suggests there is a circumstellar disk of dust with a temperature of 120 K orbiting 34 AU from the host star.


NGC 433

NGC 433 is an open cluster in the northern constellation of Cassiopeia, located at a distance of 6,500 light years from the Sun. It was discovered on September 29, 1829 by John Herschel, and was described by John Dreyer as "cluster, small, a little compressed." The cluster is considered on the poor side, with only 12 stars above magnitude 16. It has a linear diameter of , with around 479 times the mass of the Sun and an age of 65 million years.


38 Aurigae

38 Aurigae is a star located 236 light years away from the Sun in the northern constellation of Auriga. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 6.08. The star is moving further from the Earth with a heliocentric radial velocity of +34 km/s, and it has a relatively high proper motion, traversing the celestial sphere at the rate of 0.181 arc seconds per annum. It is a probable member of the Hercules stream.
This object is an aging giant star with a stellar classification of K0 III. At the age of around 3.6 billion years it is a red clump giant, which indicates it is on the horizontal branch and is generating energy via helium fusion at its core. The star has 1.59 times the mass of the Sun and has expanded to 7 times the Sun's radius. It is radiating 18 times the Sun's luminosity from its swollen photosphere at an effective temperature of 4,834 K.
38 Aurigae has a faint common proper motion companion at an angular separation of , which is equivalent to a projected separation of . This is a red dwarf star with a class of M5.3.


NGC 5678

NGC 5678 is a barred spiral galaxy in the constellation Draco. It was discovered by William Herschel on April 17, 1789.


NGC 6440

NGC 6440 is a globular cluster in the constellation Sagittarius and was discovered by William Herschel on 28 May 1786. It has an apparent magnitude of about 10, with a diameter of about 6 arcminutes, and its Shapley–Sawyer Concentration Class is V.


TV Pictoris

TV Pictoris is a rotating ellipsoidal variable star in the constellation Pictor. It ranges between apparent magnitude 7.37 - 7.53 over a period of 0.85 days. It was first discovered to be variable in 1987. The system is inclined at an angle of 54 degrees to observers on Earth. It is composed of a primary star that has a radius 4.3 times that of the sun and 1.2 times its mass, and an effective (surface) temperature of 8300 K, and a secondary star with a radius 2.1 times that of the sun and 40% of its mass, and an effective temperature of 7000 K. Both stars are less massive than expected for a main sequence star of their temperatures. The secondary rotates much faster than the primary.
The system shines with a combined spectrum of A2V. Based upon an annual parallax shift of 5.14 milliarc seconds as measured by the Hipparcos satellite, this system is from Earth. Analysing and recalibrating yields a parallax of 4.70 and hence a distance of .


Epsilon Sculptoris

Epsilon Sculptoris (ε Scl, ε Sculptoris) is a binary star in the constellation Sculptor. It is approximately 91.7 light years from Earth.
The primary component, Epsilon Sculptoris A, is a yellow-white F-type main-sequence star with an apparent magnitude of +5.29. Orbiting it with a separation of 4.6 arcseconds, or at least 125 Astronomical Units, is Epsilon Sculptoris B, a yellow G-type main sequence dwarf with an apparent magnitude of +8.6. A and B make one orbit around their centre of mass once every 1200 years.
There are two optical companions, the 15th magnitude designated Epsilon Sculptoris C at an angular separation of 15 arcseconds and the 11th magnitude Epsilon Sculptoris D, at a separation of 142 arcseconds.
This star will be in constellation Fornax around 2920 CE.


TW Hydrae b

TW Hydrae b is a likely extrasolar planet orbiting the young T Tauri star TW Hydrae approximately 176 light-years (54 parsecs, or nearly km) away in the constellation of Hydra. It is likely a Neptune-like planet orbiting at a distance of nearly 22 AU from its star.
Characteristics.
Mass, radius and temperature.
TW Hydrae b is an ice giant, an exoplanet with a radius and mass close to that of the ice giants Neptune and Uranus. It may have an equilibrium temperature of around . It has an estimated mass of around 22.72 (or 1.5 "M"Neptune) and a possible radius of 4.25 .
Host star.
The planet orbits a (K-type) T Tauri star named TW Hydrae. The star has a mass of 0.8 and a radius of 1.1 . It has a temperature of 4000 K and is about 9 million years old. In comparison, the Sun is 4.6 billion years old and has a temperature of 5778 K. Its luminosity () is 28% of that of the Sun.
The star's apparent magnitude, or how bright it appears from Earth's perspective, is 11.27. Therefore, it is too dim to be seen with the naked eye.
Orbit.
TW Hydrae b orbits its host star at a distance of 22 AU (somewhat less than the orbital distance of Neptune from the Sun, which is 30.1 AU). The orbital period is not known, although taken its similar orbital distance as Neptune, the orbital period may be around the same value.
Discovery.
First claims.
In December 2007, a team led by Johny Setiawan of the Max Planck Institute for Astronomy in Heidelberg, Germany announced discovery of a planet orbiting TW Hydrae, dubbed "TW Hydrae b" with a minimum mass around 1.2 Jupiter masses, a period of 3.56 days, and an orbital radius of 0.04 astronomical units (inside the inner rim of the protoplanetary disk). Assuming it orbited in the same plane as the outer part of the dust disk (inclination 7±1°), it would have a true mass of 9.8±3.3 Jupiter masses. However, if the inclination was similar to the inner part of the dust disk (4.3±1.0°), the mass would be 16 Jupiter masses, making it a brown dwarf. Since the star itself is so young, it was presumed this was the youngest extrasolar planet yet discovered, and essentially still in formation. (only surpassed by K2-33b and V830 Tau b, both discovered nearly 9 years later).
Disproven status.
In 2008 a team of Spanish researchers concluded that the planet did not exist: the radial velocity variations were not consistent when observed at different wavelengths, which would not occur if the origin of the radial velocity variations was caused by an orbiting planet. Instead, the data was better modelled by starspots on TW Hydrae's surface passing in and out of view as the star rotates. "Results support the spot scenario rather than the presence of a hot Jupiter around TW Hya". Similar wavelength-dependent radial velocity variations, also caused by starspots, have been detected on other T Tauri stars.
New proposal.
In 2016, astronomers studying the protoplanetary disk of the star began to speculate why there was small dust grains in the gaps, including the one at 22 AU, but not large dust grains. Further investigations began to suggest that there may be a 1.5 "M"Neptune ice giant orbiting within the gap at 22 AU, which would be responsible for the observed gaps.
The study was then published in the online journal archive arXiv on September 1, 2016, gaining wide interest from media outlets.


Mu Arae d

Mu Arae d, also known as HD 160691 d, formally named Rocinante , is an extrasolar planet orbiting the star Mu Arae of the constellation Ara.
Characteristics.
The planet has a mass about half that of Jupiter and orbits at a distance of 0.921 AU from the star with a period of 310.55 days. The planet may be located at a distance close enough to the star to receive a comparable amount of ultraviolet radiation as the Earth does from the Sun. However, it is too close to the star to be able to support liquid water at its surface. Furthermore, given its mass, the planet is likely to be a gas giant with no solid surface.
Name.
In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars. The process involved public nomination and voting for the new names. In December 2015, the IAU announced the winning name was Rocinante for this planet. The winning name was submitted by the Planetario de Pamplona, Spain. Rocinante was the horse of the lead character of the novel "El Ingenioso Hidalgo Don Quixote de la Mancha".


NGC 3675

NGC 3675 is a spiral galaxy located in the constellation Ursa Major. It is located at a distance of circa 50 million light years from Earth, which, given its apparent dimensions, means that NGC 3675 is about 100,000 light years across. It was discovered by William Herschel in 1788.
It hosts a low-ionization nuclear emission-line region (LINER). In the nucleus there is a supermassive black hole with an estimated mass of 10-39 million , based on the intrinsic velocity dispersion as measured by the Hubble Space Telescope. Although the galaxy was reported to have a strong bar visible in infrared images, it has not been any indication of bar in further observations. Its spiral disk in of type III and there is a dust structure which is more prominent to the east. The galaxy features two ring structures, with diameter 1.62 and 2.42 arcminutes. The spiral arms are tightly wound and form an inner pseudoring and they continue for one revolution outside the ring. The outer arms are very patchy and filamentary.
One supernova has been observed in NGC 3675, SN 1984R. NGC 3675 belongs to the Ursa Major Cluster, part of the Virgo Supercluster.


Nu Orionis

Nu Orionis (ν Orionis) is a binary star system in the northeastern part of the constellation Orion. It should not be confused with the variable star NU Orionis. Nu Orionis has an apparent visual magnitude of 4.42, which is bright enough to be seen with the naked eye. Based upon an annual parallax shift of 0.00632 arcseconds, the distance to this system is roughly 520 light years.
This is a single-lined spectroscopic binary system, which means that only the absorption line features of one of the components can be distinguished. The components orbit each other with a period of 131.2 days and an eccentricity of 0.64. Depending on the source, the primary is either a B-type main sequence star with a stellar classification of B3 V, or a more evolved B-type subgiant star of class B3 IV. It has an angular diameter of 0.251 mas, which, at the estimated distance of this system, yields a physical size of about 4.3 times the radius of the Sun. The mass is 6.7 times that of the Sun and it shines with 1,965 times the solar luminosity from its outer atmosphere at an effective temperature of 17,880 K.
References.
\end{align}</math></ref>


HR 2554

HR 2554, also known as V415 Carinae and A Carinae, is an eclipsing spectroscopic binary of the Algol type in the constellation of Carina whose apparent visual magnitude varies by 0.06 magnitudes and is approximately 4.39 at maximum brightness. Its primary is a G-type bright giant star and its secondary is an A-type main sequence star. It is approximately 553 light years from Earth.
HR 2554 A.
The primary component, HR 2554 A, is a yellow G-type bright giant with a mean apparent magnitude of +4.4.
HR 2554 B.
The secondary component, HR 2554 B, is a white A-type main sequence dwarf, about three magnitudes fainter than the primary.
HR 2554 binary system.
HR 2554 has two components in orbit around each other, making it a binary star. The semi-major axis of the secondary's orbit is 2.17 arcseconds. The two components regularly eclipse each other, making A Carinae a variable star. Its brightness varies by 0.06 magnitudes with a period equal to its orbital period of 195 days.


R Reticuli

R Reticuli is a Mira variable star in the southern constellation Reticulum. It is an aging red giant star on the asymptotic giant branch with a stellar classification that varies between M4e to M7.5e, being hottest near maximum visual magnitude. The brightness of the star varies between apparent visual magnitudes 6.35 and 14.2 with an average period of . The mean maximum magnitude is 7.57 and the mean minimum magnitude 13.80.
Although this star was also assigned the variable star designation S Reticuli, this designation is no longer in use.


NGC 5966

NGC 5966 is an elliptical galaxy in the constellation Boötes. NGC 5966 is its New General Catalogue designation. The galaxy was discovered by William Herschel on March 18, 1787. Based on its redshift, it is located about 220 million light-years (67 Mpc) away from the Sun.


69 Virginis

69 Virginis is a single star in the zodiac constellation of Virgo, located about 259 light years away. It is visible to the naked eye as a faint orange-hued star with an apparent visual magnitude of 4.76, although it is a suspected variable that may range in magnitude from 4.75 down to 4.79. This object is moving closer to the Earth with a heliocentric radial velocity of −13 km/s. The light from this star is polarized due to intervening interstellar dust.
This is an evolved K-type giant star with a stellar classification of , showing overabundances of CN and CH molecules in the spectrum. It is a red clump giant, which indicates is on the horizontal branch generating energy via helium fusion at its core. The star is about 288 million years old with 3.5 times the mass of the Sun and 15 times the Sun's radius. It is radiating 87 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,909 K.


List of stars in Crater

This is the list of notable stars in the constellation Crater, sorted by decreasing brightness.


NGC 3597

NGC 3597 is a galaxy located approximately 150 million light-years away in the constellation of Crater. It was discovered by John Herschel on March 21, 1835.
Characteristics.
NGC 3597 is thought to be the product of the collision of two large galaxies, and it appears to be slowly evolving to become an elliptical galaxy. Because of this, NGC 3597 is interesting to astronomers. Galaxies smashing together pool their available gas and dust, triggering new rounds of star birth. Some of this material ends up in dense pockets initially called proto-globular clusters, dozens of which festoon NGC 3597. These pockets will go on to collapse and form globular clusters, packed tightly full of millions of stars.


Mu Hydrae

μ Hydrae, Latinised as Mu Hydrae, is a solitary, orange-hued star in the equatorial constellation of Hydra. It is visible to the naked eye with an apparent visual magnitude of 3.83. Positioned just 1.8° to the south-southwest is the planetary nebula NGC 3242. Mu Hydrae has an annual parallax shift of 13.93 mas, which yields a distance estimate of 234 light years.
This is an evolved K-type giant star with a stellar classification of K4 III, having used up its core hydrogen and has expanded to around 45 times the radius of the Sun. It is a suspected variable star, with a brightness that varies about 0.03 in magnitude. The relatively cool outer atmosphere has an effective temperature of 3999 K.


35 Pegasi

35 Pegasi is a single star in the northern constellation of Pegasus. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.80. The star is located approximately 155 light years away from the Sun based on parallax, and is drifting further away with a radial velocity of +54 km/s. The star has a relatively high proper motion, traversing the celestial sphere at the rate of 0.318 arc seconds per annum.
This is an aging giant star with a stellar classification of K0III, having exhausted the hydrogen at its core and expanded to 8.5 times the Sun's radius. It is a red clump giant, indicating it is on the horizontal branch and is generating energy through helium fusion at its core. The star is five billion years old with 1.2 times the mass of the Sun. It is radiating 32 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,676 K.
There are two distant visual companions: component B, at an angular separation of and magnitude 10.0, and C, at separation 176.3″ and magnitude 10.64.


Pismis 20

Pismis 20 is a compact open cluster in Circinus. It is located at the heart of the Circinus OB1 association in the Norma arm of the Milky Way Galaxy. Pismis 20 is about away and only about 5 million years old. HD 134959, a blue supergiant variable star also called CX Circinus, is the brightest star in Pismis 20.


NGC 694

NGC 694 is a spiral galaxy approximately 136 million light-years away from Earth in the constellation of Aries. It was discovered by German astronomer Heinrich Louis d'Arrest on December 2, 1861 with the 11-inch refractor at Copenhagen.
Nearby galaxies.
NGC 694 is a member of a small galaxy group known as the NGC 691 group, the main other members of which are NGC 680, NGC 691 and NGC 697. IC 167 lies 5.5 arcminutes to the south-southeast.
Supernova SN 2014bu.
Supernova SN 2014bu was discovered in NGC 694 on June 17, 2014 by Berto Monard.
SN 2014bu had magnitude about 15.5 and was located at (coordinates: RA 01h50m58.4s, DEC +22d00m00s, J2000.0). It was classified as type II-P supernova.


R Normae

R Normae is a Mira variable star located near Eta Normae in the southern constellation of Norma.
This is an intermediate-mass red giant star that is generating part of its energy through hydrogen fusion. Because this fusion is thought to be occurring under conditions of convection, it is generating an excess of lithium. The star ranges from magnitude 6.5 to 12.8 and has a relatively long period of 496 days. Located around 2,900 light-years distant, it shines with a luminosity 7764 times that of the Sun and has a surface temperature of 3161 K.


HD 73634

HD 73634 is a single star in the southern constellation of Vela. It has the Bayer designation e Velorum; "HD 73634" is the star's designation from the "Henry Draper Catalogue". The star is white in hue and is faintly visible to the naked eye, having an apparent visual magnitude of +4.11. Parallax measurements provide a distance estimate of approximately 1,900 light years from the Sun. It is drifting further away with a radial velocity of +19 km/s.
This evolved object has received stellar classifications of A7Ia and A6II, indicating that it is a massive supergiant or bright giant star. It has 7.8 times the mass of the Sun and is around 40 million years old. The star has expanded to nearly 34 times the girth of the Sun and is radiating around 4,140 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 7,977 K.


NGC 384

NGC 384 is an elliptical galaxy located in the constellation Pisces. It was discovered on November 4, 1850 by Bindon Stoney. It was described by Dreyer as "pretty faint, pretty small, southwestern of 2.", the other being NGC 385. Along with galaxies NGC 375, NGC 379, NGC 382, NGC 383, NGC 385, NGC 386, NGC 387 and NGC 388, NGC 384 forms a galaxy cluster called Arp 331.


Andromeda XXI

Andromeda XXI (And 21, And XXI) is a moderately bright dwarf spheroidal galaxy about away from the Sun in the constellation Andromeda. It is the fourth largest Local Group dwarf spheroidal galaxy.
This large satellite of the Andromeda Galaxy (M31) has a half-light radius of nearly 1 kpc.
The discovery arose from the first year data of a photometric survey of the M31/M33 subgroupings of the Local Group by the Pan-Andromeda Archaeological Survey (PAndAS). This survey was conducted with the Megaprime/MegaCam wide-field camera mounted on the Canada-France-Hawaii Telescope.
Andromeda XXI appears as a spatial overdensity of stars. It has red giant branches at the distance of M31/M33, and follows metal-poor, [Fe/H]=-1.8 when plotted in a color-magnitude diagram.
Although moderately bright (MV=-9.9 ± 0.6), it has low surface brightness. This indicates that numerous relatively luminous M31 satellites remain undiscovered.


List of star names in Pisces

This is the list of the proper names for the stars in the constellation Pisces. (Used modern western astronomy and uranography only).


27 Piscium

27 Piscium is a binary star system in the zodiac constellation of Pisces. It is visible to the naked eye with an apparent visual magnitude of 4.88. Based upon an annual parallax shift of , it is located about 234 light years away. The system is positioned near the ecliptic and so is subject to occultation by the Moon.
This star was found to be a double by American astronomer S. W. Burnham. By 2002, sufficient position data had been gathered that orbital motion could be demonstrated, and preliminary elements were determined. The system has an orbital period of 695 years and an eccentricity of 0.766. However, the orbital elements do not fully explain the radial velocity variations, which may indicate there is a brown dwarf companion. This candidate object would have a mass of at least and is orbiting with a semimajor axis of around .
At the age of around 710 million years, the primary, component A, is a first ascent giant star on the red giant branch with a stellar classification of G8 III, which means it is generating energy through hydrogen fusion along a shell surrounding an inert helium core. It has 2.4 times the mass of the Sun and has expanded to 10 times the Sun's radius. The star is radiating about 56 times the Sun's luminosity from its photosphere at an effective temperature of 5,014 K.
In 2012, the magnitude 8.9 companion, component B, was at an angular separation of 0.80 arcseconds along a position angle of 325°.


Kepler-8

Kepler-8 is a star located in the constellation Lyra in the field of view of the Kepler Mission, a NASA-led operation tasked with discovering terrestrial planets. The star, which is slightly hotter, larger, and more massive than the Sun, has one gas giant in its orbit, Kepler-8b. This gas giant is larger than Jupiter, but is less massive, and thus more diffuse. The planet's discovery was announced to the public on January 4, 2010 along with four other planets. As the fifth confirmed planetary system verified by Kepler, it helped demonstrate the capabilities of the Kepler spacecraft.
Nomenclature and history.
Kepler-8 was named the way it was because it is home to the eighth planetary system confirmed during the course of the Kepler Mission, a NASA-directed program tasked with searching a region of the sky for terrestrial planets that transit, or cross in front of (and thereby, for a while, make dimmer) the stars that they orbit with respect to Earth. The planet in orbit around Kepler-8, Kepler-8b, was the fifth of the first five planets discovered by the Kepler spacecraft; the first three planets confirmed by Kepler had been previously discovered, and were only used to verify the accuracy of Kepler's measurements. Kepler-8b's discovery was announced to the public on January 4, 2010 at the 215th meeting of the American Astronomical Society in Washington, D.C., alongside planets in orbit around Kepler-4, Kepler-5, Kepler-6, and Kepler-7.
The data that was used to identify Kepler-8b's existence was re-examined and verified by observatories in Hawaii, Arizona, Texas, California, and the Canary Islands.
Characteristics.
Kepler-8 is situated some 1050 pc (or light years) from Earth. With a mass of 1.213 Msun and a radius of 1.486 Rsun, Kepler-8 is more massive than the Sun by about a fifth of the Sun's mass, and is nearly three halves its size. The star is predicted to be 3.84 (± 1.5) billion years old, compared to the Sun's age at 4.6 billion years. Kepler-8 has a metallicity of [Fe/H] = -0.055 (± 0.03), making it 12% less metal-rich than the metal-rich Sun; metallicity is important in stars because stars richer in metal are more likely to harbor planets. The star also has an effective temperature of 6213 (± 150) K, meaning that it is hotter than the Sun, which has an effective temperature of 5778 K.
Kepler-8 has an apparent magnitude of 13.9; in other words, as seen from Earth, Kepler-8 is an extremely dim star. It cannot be seen with the naked eye.
Planetary system.
Kepler-8b is the only planet that has been discovered orbiting of Kepler-8. With a mass of .603 MJ and a radius of 1.419 RJ, the planet is 60% the mass of, but 42% larger than planet Jupiter. The planet is diffuse, with a density of .261 grams/cc, especially in comparison to Jupiter and its density of 5.515 grams/cc. At a distance of .0483 AU, Kepler-8b orbits its star every 3.5225 days. The eccentricity of Kepler-8 is assumed to be 0, which would give the planet a circular orbit. In comparison, planet Mercury orbits the Sun at .3871 AU every 87.97 days. Mercury also has an elliptical orbit, with an eccentricity of .2056.


26 Ursae Majoris

26 Ursae Majoris is a single star in the northern circumpolar constellation of Ursa Major, located 262 light years away from the Sun. It is visible to the naked eye as a faint, white-hued star with an apparent visual magnitude of 4.47. The object is moving further from the Earth with a heliocentric radial velocity of +22 km/s.
This is an A-type main-sequence star with a stellar classification of A0 Vn, where the 'n' indicates "nebulous" lines in the spectrum due to rapid rotation. It has a high rate of spin with a projected rotational velocity of 165 km/s, which is giving it an oblate shape with an equatorial bulge that is 8% larger than the polar radius. The star is 147 million years old with just over double the mass of the Sun and twice the Sun's radius. It is radiating 99 times the Sun's luminosity from its photosphere at an effective temperature of 9,757 K.


HD 59890

HD 59890 is a class G3Ib (yellow supergiant) star in the constellation Puppis. Its apparent magnitude is 4.65 and it is approximately 1500 light years away based on parallax.


HD 90264

HD 90264 is a binary star system in the southern constellation of Carina. It has the Bayer designation of "L Carinae", while "HD 90264" is the star's identifier in the "Henry Draper catalogue". This system has a blue-white hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.97. It is located at a distance of approximately 402 light years from the Sun based on parallax, and is drifting further away with a radial velocity of around +12 km/s. The system is a member of the Lower Centaurus Crux association of the Sco-Cen Complex.
This system was found to be a close double-lined spectroscopic binary in 1977, consisting of two B-type main-sequence stars. It has a near circular orbit with a period of 15.727 days and a semimajor axis of . They appear to be spin-orbit synchronized. Both stars appear to be deficient in helium. The primary is a helium variable star while the companion is a mercury-manganese star. The variability of both stars aligns favorably with the orbital period.


Epsilon Carinae

Epsilon Carinae (ε Carinae, abbreviated Epsilon Car, ε Car), officially named Avior , is a binary star in the southern constellation of Carina. At apparent magnitude +1.86 it is one of the brightest stars in the night sky, but is not visible from the northern hemisphere. The False Cross is an asterism formed of Delta Velorum, Kappa Velorum, Iota Carinae and ε Carinae. It is so called because it is sometimes mistaken for the Southern Cross, causing errors in astronavigation.
Epsilon Carinae is located roughly from the Sun. Measurements during the Hipparcos mission give the pair an angular separation of 0.46 arcseconds with a difference in magnitude of 2.0. At their estimated distance, this angle is equivalent to a physical separation of around 4 astronomical units.
The primary component has an apparent visual magnitude of 2.2, which by itself would still make it the third-brightest star in the constellation. It is an evolved giant star with a stellar classification of K0 III. However, examination of the ultraviolet flux from this star suggests it may instead be of spectral type K7. The fainter secondary companion has an apparent visual magnitude of 4.1, which, if it were a solitary star, would be bright enough to be seen with the naked eye. This is a hot, core hydrogen-fusing B-type main sequence star of spectral class B2 Vp. The secondary may itself have an orbiting stellar companion of spectral class F8. This pair may form an eclipsing binary system with a period of 785 days (2.15 years), resulting in a magnitude change of 0.12 during each eclipse.
Etymology.
"ε Carinae" (Latinised to "Epsilon Carinae") is the star's Bayer designation.
The name "Avior" is not classical in origin. It was assigned to the star by HM Nautical Almanac Office in the late 1930s during the creation of The Air Almanac, a navigational almanac for the Royal Air Force. Of the fifty-seven navigation stars included in the new almanac, two had no classical names: Epsilon Carinae and Alpha Pavonis. The RAF insisted that all of the stars must have names, so new names were invented. Alpha Pavonis was named "Peacock", a translation of Pavo, whilst Epsilon Carinae was called "Avior". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included "Avior" for this star.
In Chinese, (), meaning "Sea Rock", refers to an asterism consisting of ε Carinae, Iota Carinae, HD 83183, HD 84810 and Upsilon Carinae . Consequently, ε Carinae itself is known as (, .)


7 Draconis

7 Draconis, also named Tianyi , is a single star in the northern circumpolar constellation of Draco. It is visible to the naked eye as a faint orange-hued star with a stellar classification of 5.43. Based upon an annual parallax shift of as seen from the Earth, the star is located approximately 780 light-years from the Sun.
This is an evolved giant star with a stellar classification of K5 III. The measured angular diameter of this star, after correction for limb darkening, is . At its estimated distance, this yields a physical size of about 67 times the radius of the Sun. It is radiating about 1,024 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,945 K.
Nomenclature.
7 Draconis is the star's Flamsteed designation.
The star bore the traditional Chinese name of "Tianyi", from 天乙 ("Tiān Yǐ") or 天一 ("Tiān Yī", the Celestial Great One), a deity in Taoism. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name "Tianyi" for this star on 30 June 2017 and it is now so entered on the List of IAU-approved Star Names.
References.
\end{align}</math></ref>


93 Herculis

93 Herculis is a star located around 750 light years away from the Sun in the northern constellation of Hercules. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.67 The brightness of the star is diminished by an extinction of 0.21 due to interstellar dust. It is moving closer to the Earth with a heliocentric radial velocity of −24.5 km/s. This star, together with 95 Her, 102 Her, and 109 Her, made up the obsolete constellation Cerberus.
This object has a stellar classification of K0.5IIb, which indicates it is an evolved bright giant. With the supply of hydrogen at its core exhausted, the star has expanded to 51 times the Sun's radius. It is radiating around 919 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,471 K. It is generally deficient in metal elements, but appears weakly enhanced in barium and other heavier elements. This is a suspected barium star and hence may have a white dwarf companion in orbit.


Eta Leporis

Eta Leporis, Latinized from η Leporis, is a single, yellow-white hued star in the southern constellation of Lepus, the hare. It is visible to the naked eye with an apparent visual magnitude of approximately 3.72. The annual parallax shift of 67.21 mas yields a distance estimate of 49 light years. It is moving closer to the Sun with a radial velocity of −1.6 km/s.
This is an ordinary F-type main-sequence star with a stellar classification of F2 V. It is about 1.8 billion years old and spinning with a projected rotational velocity of 26 km/s. The star has 1.4 times the mass of the Sun and 1.5 times the Sun's radius. It shines with six times the Sun's luminosity, which is being radiated from its photosphere at an effective temperature of around 6,899 K. Using the IRS instrument on the Spitzer Space Telescope, excess infrared emission has been observed from the star, which can be modeled by a dust disk extending from 1 to 16 astronomical units from Eta Leporis.


RU Lupi

RU Lupi is a star in the constellation of Lupus, located in the young Lupus Star Forming Region. Based on parallax measurements, the distance to this star is about . The apparent visual magnitude is 10.5, so viewing it would require a telescope with an aperture of
, but preferably larger.
This is a T Tauri star, which is a stage that a newly formed, low-mass star passes through before settling down onto the main sequence, where it will generate all of its energy through hydrogen fusion at its core. The age of this star is about 2–3 million years. It is showing random fluctuations in luminosity, including variations in ultraviolet and X-ray emissions.
The spectrum of the star is displaying emission lines of hydrogen overlaid on the star's normal spectra. This may be caused by the impact of infalling gas on the star's outer envelope, combined with the signature of a strong outflowing wind near the star. Mass is accreting onto the star at the rate of about times the mass of the Sun per year.
RU Lupi has an estimated mass of 0.6–0.7 times the mass of the Sun and 1.6 times the Sun's radius. It is radiating more than double the luminosity of the Sun, at an effective temperature of about 3,950 K. RU Lupi is surrounded by a circumstellar disk of dust that has a combined mass of up to 0.032 times the mass of the Sun. The particles in the disk vary in size, but range up to a centimeter in cross-section.
The star exhibits periodic radial velocity variations that are attributed to stellar spots on the surface of the star, based on the correlation between the radial velocity and the bisector inverse slope (a quantity that parametrises the shape of the spectral lines). The time period of the variations makes it unlikely that they are caused by stellar pulsations as these would be expected to occur on much shorter timescales (hours rather than days), and the correlation with the bisector inverse slope makes it unlikely that an orbiting companion is responsible as reflex motion would not cause the line profile variations.


HD 69863

HD 69863 is a binary star system in the southern constellation of Carina. It is visible to the naked eye as a dim point of light with a combined apparent visual magnitude of 5.16. The system is located at a distance of about255 light years from the Sun based on parallax. The dual nature of this system was announced in 1832 by German astronomer Carl Rümker. As of 2015, the pair had an angular separation of along a position angle of 70°.
The brighter primary, designated component A, has a visual magnitude of 5.27 and is an A-type main-sequence star with a stellar classification of A2V. It is 635 million years old and is spinning with a projected rotational velocity of 191 km/s. The star has 2.1 times the mass of the Sun.
The magnitude 7.62 companion, component B, is a F-type main-sequence star with a class of F2V. It is radiating four times the luminosity of the Sun from its photosphere at an effective temperature of 6,806 K. The system is a source for X-ray emission, which is most likely coming from the secondary.


Sigma Geminorum

Sigma Geminorum (σ Gem) is a binary star system in the constellation Gemini, just to the northeast of Pollux. It is visible to the naked eye with an apparent visual magnitude of 4.20. Based upon an annual parallax shift of 26.08 mas, it is located 125 light years from the Sun.
Sigma Geminorum is a single-lined spectroscopic binary, which means that the spectrum of only one of the components can be discerned. It is an RS Canum Venaticorum variable with a period of 19.6 days, matching the orbital period. The stellar luminosity shows indications of ellipsoidal variation, as the primary component is partly filling its Roche lobe due to gravitational interaction between the two stars.
The primary component is an evolved K-type giant star with a stellar classification of K1 III. It has a relatively high rate of spin for a giant star, showing a projected rotational velocity of 26.2 km/s and a rotation period of 19.47 days. This rate is being maintained by the tidal interaction between the two stars. The surface of the primary has large star spots that are locked onto the face oriented toward the secondary component. These spots appear to migrate poleward at an average velocity of . The surface activity makes the star a bright X-ray emission source with a luminosity of . It displays indications of anti-solar differential rotation.
The primary has 1.28 times the mass of the Sun, but has expanded to 10.1 times the Sun's radius. It shines with 39 times the solar luminosity from its outer atmosphere at an effective temperature of 4571 K. It is roughly 5 billion years old.


Beta Equulei

Beta Equulei, Latinized from β Equulei, is the Bayer designation for a solitary star in the northern constellation of Equuleus. It is faintly visible to the naked eye with an apparent visual magnitude of 5.16. The annual parallax shift is 11.27 mas, indicating a separation of around 289 light years from the Sun. It is drifting closer with a radial velocity of −11 km/s.
This is an ordinary A-type main sequence star with a stellar classification of A3 V. It has 2.7 times the mass of the Sun and about four times the Sun's radius. The star is around 600 million years old – 93% of the way through its main sequence lifetime – and is spinning with a projected rotational velocity of 58 km/s. It is radiating 78 times the luminosity of the Sun from its photosphere at an effective temperature of about 9,000 K. The star emits an infrared excess indicating the presence of a dusty debris disk. The mean temperature of the dust is 85 K, indicating the semimajor axis of its orbit is 104 AU.
β Equulei has four optical companions. They are not physically associated with the star described above.


NGC 595

NGC 595 is an H II region in the Triangulum Galaxy. It was discovered by Heinrich Ludwig d'Arrest on October 1, 1864.


Kepler-68d

Kepler-68d is a gas giant with the minimum mass about the same as Jupiter. It is at least a jovian-mass planet orbiting 1.4 astronomical units from its parent star, Kepler-68, well within habitable zone of the star. It was detected by radial velocity.
After planets Kepler-68b and c were detected by observing planetary transits in front of its star, doppler spectroscopy measurements were used to make follow-up observations of the star. Kepler-68d was discovered using that method.


Omicron Hydrae

Omicron Hydrae (ο Hya) is the Bayer designation for a solitary star in the equatorial constellation Hydra. At one time it bore the Flamsteed designation 25 Crateris, but this is no longer used by astronomers so as to avoid confusion. With an apparent visual magnitude of 4.70, this star is visible to the naked eye. Based upon an annual parallax shift of 7.27 mas, it is located around 449 light years from the Sun.
This is a B-type main sequence star with a stellar classification of B9 V. It has completed an estimated of its lifetime on the main sequence. With 3.56 times the mass of the Sun, it radiates 309 times the Sun's luminosity from its outer atmosphere at an effective temperature of 10,495 K. The rate of spin is relatively high, with a projected rotational velocity of 160 km/s.


Robur Carolinum

Robur Carolinum (Latin for "Charles' oak") was a constellation created by the English astronomer Edmond Halley in 1679. The name refers to the Royal Oak where Charles II was said to have hidden from the troops of Oliver Cromwell after the Battle of Worcester. It was between the constellations of Centaurus and Carina, extending into half of Vela.
Robur Carolinum as a constellation never gained popularity, probably because it used the star Eta Carinae and the Eta Carinae Nebula, and was soon dropped from use after only fifty years. Nicolas Louis de Lacaille also complained bitterly that it took some of the finest stars from Argo Navis. Its brightest star was Beta Carinae (β Car) or Miaplacidus, which was known as α Roburis or α Roburis Carolii.


Theta Pyxidis

Theta Pyxidis (Theta Pyx, θ Pyxidis, θ Pyx) is a red M-type giant in the constellation Pyxis. It is approximately 500 ± 30 light years from Earth. It is of spectral type M1III and semi-regular variable with two measured periods of 13 and 98.3 days, and an average visual magnitude of 4.71, It shines with a luminosity approximately 970 times that of the Sun and has a surface temperature of 3825 K. It has a diameter around 54 times that of the Sun.
Theta Pyxidis is moving through the Galaxy at a speed of 22.8 km/s relative to the Sun. Its projected Galactic orbit carries it between 21,200 and 24,700 light years from the center of the Galaxy. It came closest to the Sun 5.8 million years ago when it had brightened to magnitude 3.12 from a distance of 241 light years.


Eta Centauri

Eta Centauri, Latinized from η Centauri, is a star in the southern constellation of Centaurus. It has an apparent visual magnitude of +2.35 and is located at a distance of around . In traditional Chinese astronomy, Eta Centauri was known as (meaning: the Second (Star) of "Koo Low").
The stellar classification of this star is B1.5 Vne, indicating that it is a B-type main sequence star. The 'n' suffix means that the absorption lines are broadened from rapid rotation. It has a projected rotational velocity of 330 km s−1 and completes a full rotation in less than a day. This is a Be star as shown by the 'e' suffix, which means it has variable emissions in its hydrogen spectral lines. This emission can be modeled by a decretion disk of gas that has been ejected from the star and now follows a near Keplerian orbit around the central body. Finally it is slightly variable, and classified as a Gamma Cassiopeiae variable star with multiple periods of variability. The International Variable Star Index lists Eta Centauri as both a Gamma Cassiopeiae variable and a Lambda Eridani variable.
Eta Centauri has about 12 times the mass of the Sun, placing it above the dividing line between stars that evolve into white dwarfs and those that turn into supernovae. It is radiating 8,700 times as much luminosity as the Sun from its outer atmosphere at an effective temperature of 25,700 K. This heat causes the star to glow with the blue-white hue common to B-type stars. Eta Centauri is a proper motion member of the Upper-Centaurus Lupus sub-group in the Scorpius-Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.