SHARE









The US National Aeronautics and Space Administration, NASA, revealed on Monday the discovery of an exoplanet resembling Mercury. The new finding made by the NASA Kepler Space Telescope will help to investigate the origin and evolution of Mercury, specialists say, since it is the first time that astronomers find another world that resembles the Mercury planet, the most unknown planet in our Solar System.

K2-229 b Mercury-like exoplanet is made of iron and nickel

The new exoplanet, which has been named K2-229 b, is, in fact, a bigger version of Mercury as it is four times bigger and five times hotter, explained the US space agency.

The exoplanet orbits a star like our Sun, however, the diurnal side of the planet can reach temperatures so high that they can vaporize rocks – about 2,000 degrees Celsius.

K2-229 b is mainly composed of heavy elements, such as iron and nickel, which can survive near the heat of a star.

Unlike Earth, which has only 35 percent iron, K2-229 b, whose name comes from the mission that found it, has 70 percent iron, exactly like Mercury.

The Mercury-like exoplanet can help scientists learn more about Mercury and rocky planets formation

Earth, Venus, Mars, and some exoplanets have a mass composed of approximately 30% metallic core and 70% silicate mantle. On the other hand, the composition of Mercury, located on the inner border of the Solar System, is exactly the opposite.

Astronomers believe that the new discovery can help explain what happened to Mercury and how the rocky planets in the Solar System were formed.

K2-229b is so close to its star that it is possible that the extreme radiation evaporated the mantle, its outermost part, and an atmosphere of silicate vapors formed, according to the astronomers.

Besides, some of this material could have been lost in space, which would explain the unique composition of the planet. An alternative explanation would be the impact with large asteroids, analogous to what happened to the Earth when the Moon was formed.

In conclusion, NASA has just revealed the discovery made by Kepler Space Telescope of an exoplanet similar to Mercuri.</s>We are grateful to the HARPS observers who conducted part of the visitor-mode observations at La Silla Observatory: R. I. Bustos, N. Astudillo, A. Wyttenbach, E. Linder, X. Bonfils, E. Hébrard and A. Suarez. A.S. thanks E. Hugot for comments on the manuscript. This publication is based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 198.C-0168. This publication makes use of The Data & Analysis Center for Exoplanets (DACE), which is a facility based at the University of Geneva (CH) dedicated to extrasolar planet data visualization, exchange and analysis. DACE is a platform of the Swiss National Centre of Competence in Research (NCCR) PlanetS, federating the Swiss expertise in exoplanet research. The DACE platform is available at https://dace.unige.ch. This research has made use of the NASA (National Aeronautics and Space Administration) Exoplanet Archive, which is operated by the California Institute of Technology, under contract with NASA under the Exoplanet Exploration Program. This research has made use of the VizieR catalogue access tool, CDS (http://vizier.u-strasbg.fr/vizier/surveys.htx). The original description of the VizieR service was published in ref. 76. This publication makes use of data products from the Two-Micron All-Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by NASA and the National Science Foundation. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by NASA. The Porto group acknowledges support from Fundação para a Ciência e a Tecnologia (FCT) through national funds and from FEDER through COMPETE2020 by the grants UID/FIS/04434/2013 & POCI–01–0145-FEDER–007672, PTDC/FIS-AST/1526/2014 & POCI–01–0145-FEDER–016886 and PTDC/FIS-AST/7073/2014 & POCI-01-0145-FEDER-016880. FCT is further acknowledged through the Investigador FCT contracts IF/01312/2014/CP1215/CT0004 (S.C.C.B.), IF/00849/2015/CP1273/CT0003 (E.D.M.), IF/00650/2015/CP1273/CT0001 (V.A.), IF/01037/2013/CP1191/CT0001 (P.F.), IF/00169/2012/CP0150/CT0002 (N.C.S.) and IF/00028/2014/CP1215/CT0002 (S.G.S.) and for the fellowships SFRH/BD/93848/2013 (J.P.F.), PD/BD/128119/2016 (S.H.) and PD/BD/52700/2014 (J.J.N.), which are funded by FCT (Portugal) and POPH/FSE (EC). J.L.-B. acknowledges support from the Marie Curie Actions of the European Commission (FP7-COFUND). D.Bar. has been supported by the Spanish grant ESP2015-65712-C5-1-R. D.J.A. is funded under STFC consolidated grant reference ST/P000495/1. D.J.A.B. acknowledges support from the University of Warwick and the UKSA. E.F. is funded by the Qatar National Research Foundation (programme QNRF-NPRP-X-019-1). X.D. is grateful to the Society in Science–The Branco Weiss Fellowship for its financial support. R.L. thanks CNES for financial support through its postdoctoral programme. The project leading to this publication has received funding from Excellence Initiative of Aix-Marseille University–A*MIDEX, a French Investissements d’Avenir programme. The French group acknowledges financial support from the French Programme National de Planétologie (PNP, INSU). This work has been carried out in the frame of the NCCR PlanetS supported by the Swiss National Science Foundation (SNSF).</s>Surface of Mercury. Credit: NASA/JHUAPL/Carnegie Institution of Washington/USGS/Arizona State University

A hot, metallic, Earth-sized planet with a density similar to Mercury—situated 340 light years away—has been detected and characterised by a global team of astronomers, including the University of Warwick.

Named K2-229b, the planet is almost 20% larger than Earth but has a mass which is over two-and-a-half times greater—and reaches a dayside temperature of over 2000°C (2330 Kelvin).

It finds itself very close to its host star (0.012 AU, around a hundredth of the distance between the Earth and the Sun), which itself is a medium-sized active K dwarf in the Virgo Constellation. K2-229b orbits this star every fourteen hours.

Led overall by researchers at Aix-Marseille Université in France, Dr. David Armstrong and colleagues at the University of Warwick's Astronomy and Astrophysics Group independently detected the planet in the first instance, alongside researchers at the Universidade do Porto.

Using the K2 telescope, Dr. Armstrong and colleagues employed the Doppler spectroscopy technique—also known as the 'wobble method' to discover and characterise this faraway planet.

The astronomers knew the planet was there due to dips in the light from its host star as it orbited, periodically blocking starlight.

They then calculated the size, position and mass of K2-229b by measuring the radial velocity of the star, and finding out how much the starlight 'wobbles' during orbit, due to the gravitational tug from the planet, which changes depending on the planet's size.

Dr. David Armstrong from the University of Warwick's Astronomy and Astrophysics Group, commented:

"Mercury stands out from the other Solar System terrestrial planets, showing a very high fraction of iron and implying it formed in a different way. We were surprised to see an exoplanet with the same high density, showing that Mercury-like planets are perhaps not as rare as we thought.

"Interestingly K2-229b is also the innermost planet in a system of at least 3 planets, though all three orbit much closer to their star than Mercury. More discoveries like this will help us shed light on the formation of these unusual planets, as well as Mercury itself."

The dense, metallic nature of K2-229b has numerous potential origins, and one hypothesis is that its atmosphere might have been eroded by intense stellar wind and flares, as the planet is so close to its star.

Dr. David Armstrong from the University of Warwick's Astronomy and Astrophysics Group. Credit: University of Warwick

Another possibility is that K2-229b was formed after a huge impact between two giant astronomical bodies in space billions of years ago—much like the theory that the Moon was formed after Earth collided with a body the size of Mars.

Discovering details about far-flung planets across the universe gives us more clues as to how planets in our own solar system formed. As K2-229b is similar to Mercury, knowing more about the former can potentially reveal more about the latter.

Explore further 'Monster' planet discovery challenges formation theory

More information: An Earth-sized exoplanet with a Mercury-like composition, Nature Astronomy, nature.com/articles/doi:10.1038/s41550-018-0420-5 Journal information: Nature Astronomy An Earth-sized exoplanet with a Mercury-like composition,</s>March 28 (UPI) -- Astronomers have discovered a hot and metallic exoplanet situated 340 light-years from Earth.

Though K2-229b is just 20 percent larger than Earth, its mass is 2.5 times greater, making it about as dense as Mercury. The alien planet orbits an active K dwarf in the Virgo Constellation at a distance of more than 1 million miles.

Astronomers at Aix-Marseille University in France confirmed the presence of K2-229b using data from the K2 telescope and a type of Doppler spectroscopy technique called the "wobble method."

Periodic dimming first revealed the presence of the Mercury-like planet, but scientists were able to better characterize its mass and composition by measuring the wobble of the K dwarf's light caused by the gravitational influence of K2-229b.

"Mercury stands out from the other solar system terrestrial planets, showing a very high fraction of iron and implying it formed in a different way," David Armstrong, an astronomer at the University of Warwick, said in a news release. "We were surprised to see an exoplanet with the same high density, showing that Mercury-like planets are perhaps not as rare as we thought."

"Interestingly K2-229b is also the innermost planet in a system of at least 3 planets, though all three orbit much closer to their star than Mercury," Armstrong said. "More discoveries like this will help us shed light on the formation of these unusual planets, as well as Mercury itself."

It's possible the exoplanet's dense, metallic nature is the product of its close proximity to its host star. Daily temperatures on the exoplanet exceed 2,000 degrees Celsius. When the planet was forming, solar flares may have stripped away its atmosphere and outer layers, leaving behind only a dense core.

It's also possible that K2-229b is the product of a violent collision between two large astronomical bodies, similar to the collision astronomers believe forged Earth's moon.

Studying the evolution of distant solar systems and the nature of the planets that reside in them -- including Mercury-like exoplanets like K2-229b -- can offer clues to the history of our own solar system, researchers say.

Researchers described the discovery of K2-229b this week in the journal Nature.</s>A hot, metallic, Earth-sized planet with a density similar to Mercury -- situated 260 million light years away- - has been detected and characterized by a global team of astronomers, including the University of Warwick
• Hot, metallic, Earth-sized planet with a density similar to Mercury detected 260 million light years away and characterised by global team of astronomers, including the University of Warwick
• K2-229b is 20% larger than Earth but has a mass 2.6 times greater - and a dayside temperature of over 2000°C
• Discovering details about far-flung planets across the universe gives us more clues as to how planets in our own solar system formed

A hot, metallic, Earth-sized planet with a density similar to Mercury - situated 260 million light years away -- has been detected and characterised by a global team of astronomers, including the University of Warwick.

Named K2-229b, the planet is almost 20% larger than Earth but has a mass which is over two-and-a-half times greater -- and reaches a dayside temperature of over 2000°C (2330 Kelvin).

It finds itself very close to its host star (0.012 AU, around a hundredth of the distance between the Earth and the Sun), which itself is a medium-sized active K dwarf in the Virgo Constellation. K2-229b orbits this star every fourteen hours.

Led overall by researchers at Aix-Marseille Université in France, Dr David Armstrong and colleagues at the University of Warwick's Astronomy and Astrophysics Group independently detected the planet in the first instance, alongside researchers at the Universidade do Porto.

Using the K2 telescope, Dr Armstrong and colleagues employed the Doppler spectroscopy technique -- also known as the 'wobble method' to discover and characterise this faraway planet.

The astronomers knew the planet was there due to dips in the light from its host star as it orbited, periodically blocking starlight.

They then calculated the size, position and mass of K2-229b by measuring the radial velocity of the star, and finding out how much the starlight 'wobbles' during orbit, due to the gravitational tug from the planet, which changes depending on the planet's size.

Dr David Armstrong from the University of Warwick's Astronomy and Astrophysics Group, commented:

"Mercury stands out from the other Solar System terrestrial planets, showing a very high fraction of iron and implying it formed in a different way. We were surprised to see an exoplanet with the same high density, showing that Mercury-like planets are perhaps not as rare as we thought.

"Interestingly K2-229b is also the innermost planet in a system of at least 3 planets, though all three orbit much closer to their star than Mercury. More discoveries like this will help us shed light on the formation of these unusual planets, as well as Mercury itself."

The dense, metallic nature of K2-229b has numerous potential origins, and one hypothesis is that its atmosphere might have been eroded by intense stellar wind and flares, as the planet is so close to its star.

Another possibility is that K2-229b was formed after a huge impact between two giant astronomical bodies in space billions of years ago -- much like the theory that the Moon was formed after Earth collided with a body the size of Mars.

Discovering details about far-flung planets across the universe gives us more clues as to how planets in our own solar system formed. As K2-229b is similar to Mercury, knowing more about the former can potentially reveal more about the latter.

The research, 'An Earth-sized exoplanet with a Mercury-like composition', is published in Nature Astronomy. DOI 10.1038/s41550-018-0420-5

It was led by Aix-Marseille Université in France. The UK research was funded by the Science and Technology Facilities Council.</s>Scientists have discovered a hot, metallic, Earth-sized planet orbiting a dwarf star located 260 million light years away. Named K2-229b, the planet is almost 20 per cent larger than Earth but has a mass which is over two-and-a-half times greater. It reaches a day side temperature of over 2000 degrees Celsius. It is located very close to its host star (0.012 AU, around a hundredth of the distance between the Earth and the Sun), which itself is a medium-sized active K dwarf in the Virgo Constellation. K2-229b orbits this star every fourteen hours.

Using the K2 telescope, researchers from Aix-Marseille Universite in France and University of Warwick in the UK employed the Doppler spectroscopy technique – also known as the ‘wobble method’ – to discover and characterise this faraway planet. The astronomers knew the planet was there due to dips in the light from its host star as it orbited, periodically blocking starlight.

They then calculated the size, position and mass of K2-229b by measuring the radial velocity of the star, and finding out how much the starlight ‘wobbles’ during orbit, due to the gravitational tug from the planet, which changes depending on the planet’s size. “Mercury stands out from the other Solar System terrestrial planets, showing a very high fraction of iron and implying it formed in a different way,” said David Armstrong from the University of Warwick.

“We were surprised to see an exoplanet with the same high density, showing that Mercury-like planets are perhaps not as rare as we thought,” Armstrong said. “Interestingly K2-229b is also the innermost planet in a system of at least three planets, though all three orbit much closer to their star than Mercury,” he said. The dense, metallic nature of K2-229b has numerous potential origins, and one hypothesis is that its atmosphere might have been eroded by intense stellar wind and flares, as the planet is so close to its star.

Another possibility is that K2-229b was formed after a huge impact between two giant astronomical bodies in space billions of years ago – much like the theory that the Moon was formed after Earth collided with a body the size of Mars. Discovering details about far-flung planets across the universe gives us more clues as to how planets in our own solar system formed, researchers said. As K2-229b is similar to Mercury, knowing more about the former can potentially reveal more about the latter, they said.</s>Scientists have discovered a hot, metallic, Earth-sized planet with a density similar to Mercury located 339 light years away from Earth.

“Mercury stands out from the other solar system terrestrial planets, showing a very high fraction of iron and implying it formed in a different way. We were surprised to see an exoplanet with the same high density, showing that Mercury-like planets are perhaps not as rare as we thought,” says David Armstrong, of the astronomy and astrophysics group at the University of Warwick.

Named K2-229b, the planet is almost 20 percent larger than Earth but has a mass which is over two-and-a-half times greater—and reaches a dayside temperature of over 2000°C (2330 Kelvin).

The new planet is very close to its host star (0.012 AU, around a hundredth of the distance between the Earth and the Sun), which itself is a medium-sized active K dwarf in the Virgo Constellation. K2-229b orbits this star every fourteen hours.

Using the K2 telescope, scientists used the Doppler spectroscopy technique—also known as the “wobble method” to discover and characterize the planet. Astronomers knew the planet was there thanks to dips in the light from its host star as it orbited.

They then calculated the size, position, and mass of K2-229b by measuring the radial velocity of the star, and finding out how much the starlight wobbles during orbit, due to the planet’s gravitational tug, which changes depending on its size.

“Interestingly K2-229b is also the innermost planet in a system of at least three planets, though all three orbit much closer to their star than Mercury. More discoveries like this will help us shed light on the formation of these unusual planets, as well as Mercury itself,” Armstrong says.

Scorching hot Mercury has more ice than we thought

The dense, metallic nature of K2-229b has numerous potential origins. One hypothesis is that its atmosphere might have been eroded by intense stellar wind and flares, as the planet is so close to its star.

Another possibility is that K2-229b formed after a huge impact between two giant astronomical bodies in space billions of years ago—much like the theory that the moon was formed after Earth collided with a body the size of Mars.

Researchers report their findings in Nature Astronomy. Researchers from Aix-Marseille Université in France and the Universidade do Porto in Portugal are coauthors.</s>NASA’s Kepler Space Telescope has helped discover a new kind of exploding star. Buzz60</s>An international team of astronomers has discovered a new Earth-sized exoplanet, a distant world that could reveal the origin story of Mercury, one of the hottest planets of our solar system.

The new planet, dubbed K2-229b, sits some 339 light years away from us and orbits its star — a medium-sized active K dwarf in the Virgo Constellation — every fourteen hours. It’s nearly 20% larger than Earth, but the find doesn’t improve our chances of finding life-support on an alien planet.

This is because K2-229b is far from being in the habitable zone. The planet is located eerily close to its star, approximately a hundredth of the distance between Earth and sun, and makes one hell of a place to live where daytime temperatures going way beyond 2000°C.

An international team of astronomers using the K2 space telescope first spotted the distant world. Essentially, they took a close look at the light emitted from its host star and witnessed regular dimming periods. These dips hinted at the presence of an orbiting body or a planet, which came between the Earth and the distant star from time to time and blocked the light.

The group started employing sophisticated techniques to delve into the specifics of the newly discovered planet. They discovered K2-229b is just a little bigger than Earth, but its mass is two and a half times greater.

The most interesting bit, however, was the similarity between Mercury and the new planet. They both are not only metallic and extremely hot but also carry the same high-level of density.

“Mercury stands out from the other Solar System terrestrial planets, showing a very high fraction of iron and implying it formed in a different way,” University of Warwick’s David Armstrong, one of the members of the team, said in a statement. “We were surprised to see an exoplanet with the same high density, showing that Mercury-like planets are perhaps not as rare as we thought.”

The team now believes further studies revolving around the new planet could help them understand how Mercury and other rare planets like it first came to be. It is also worth noting K2-229b is not orbiting its star alone. The planet is the innermost member of “a system of at least 3 planets, though all three orbit much closer to their star than Mercury," according to Armstrong.

For now, scientists have two hypothesis regarding the past of K2-229b. The first relies on the closeness between the planet and its star and suggests intense solar winds and flares might have evaporated its atmosphere, while the second hints at a more chaotic past where a collision between two massive astronomical bodies would have led to the formation of the planet. This is much like the famous Moon theory which suggests the satellite formed after Earth collided with a body as big as Mars.

The discovery was published in a paper titled "An Earth-sized exoplanet with a Mercury-like composition" in journal Nature Astronomy.</s>Astronomer Ed Shaya was in his office looking at data from NASA’s Kepler space telescope in 2012 when he noticed something unusual: The light from a galaxy had quickly brightened by 10 percent. The sudden bump in light got Shaya instantly excited, but also nervous. The effect could be explained by the massive explosion of a star — a supernova! — or, more troublingly, a computer error.

“I just remember on that day, not knowing whether I should believe it or not,” he remembers. Rather than celebrate, he thought, “Did I make a mistake? Am I doing this all wrong?”

Stellar explosions forge and distribute materials that make up the world in which we live, and also hold clues to how fast the universe is expanding. By understanding supernovae, scientists can unlock mysteries that are key to what we are made of and the fate of our universe. But to get the full picture, scientists must observe supernovae from a variety of perspectives, especially in the first moments of the explosion. That’s really difficult — there’s no telling when or where a supernova might happen next.

A small group of astronomers, including Shaya, realized Kepler could offer a new technique for supernova-hunting. Launched in 2009, Kepler is best known for having discovered thousands of exoplanets. But as a telescope that stares at single patches of space for long periods of time, it can capture a vast trove of other cosmic treasures –especially the kind that change rapidly or pop in and out of view, like supernovae.

“Kepler opened up a new way of looking at the sky,” said Jessie Dotson, Kepler’s project scientist, based at NASA’s Ames Research Center in California’s Silicon Valley. “It was designed to do one thing really well, which was to find planets around other stars. In order to do that, it had to deliver high-precision, continuous data, which has been valuable for other areas of astronomy.”

Originally, Shaya and colleagues were looking for active galactic nuclei in their Kepler data. An active galactic nucleus is an extremely bright area at the center of a galaxy where a voracious black hole is surrounded by a disk of hot gas. They had thought about searching for supernovae, but since supernovae are such rare events, they didn’t mention it in their proposal. “It was too iffy,” Shaya said.

Unsure if the supernova signal he found was real, Shaya and his University of Maryland colleague Robert Olling spent months developing software to better calibrate Kepler data, taking into account variations in temperature and pointing of the instrument. Still, the supernova signal persisted. In fact, they found five more supernovae in their Kepler sample of more than 400 galaxies. When Olling showed one of the signals to Armin Rest, who is now an astronomer at the Space Telescope Science Institute in Baltlimore, Rest’s jaw dropped. “I started to drool,” he said. The door had opened to a new way of tracking and understanding stellar explosions.

Today, these astronomers are part of the Kepler Extra-Galactic Survey, a collaboration between seven scientists in the United States, Australia and Chile looking for supernovae and active galactic nuclei to explore the physics of our universe. To date, they have found more than 20 supernovae using data from the Kepler spacecraft, including an exotic type reported by Rest in a new study in Nature Astronomy. Many more are currently being recorded by Kepler’s ongoing observations.

“We have some of the best-understood supernovae,” said Brad Tucker, astronomer at the Mt. Stromlo Observatory at the Australian National University, who is part of the Kepler Extra-Galactic Survey.



 Why do we care about supernovae?

A longstanding mystery in astrophysics is how and why stars explode in different ways. One kind of supernova happens when a dense, dead star called a white dwarf explodes. A second kind happens when a single gigantic star nears the end of its life, and its core can no longer withstand the gravitational forces acting on it. The details of these general categories are still being worked out.

The first kind, called “type Ia” (pronounced as “one a”) is special because the intrinsic brightness of each of these supernovae is almost the same. Astronomers have used this standard property to measure the expansion of the universe and found the more distant supernovae were less bright than expected. This indicated they were farther away than scientists had thought, as the light had become stretched out over expanding space. This proved that the universe is expanding at an accelerating rate and earned those researchers the Nobel Prize in 2011. The leading theory is that a mysterious force called “dark energy” is pushing everything in the universe apart from everything else, faster and faster.

But as astronomers find more and more examples of type Ia explosions, including with Kepler, they realize not all are created equal. While some of these supernovae happen when a white dwarf robs its companion of too much matter, others are the result of two white dwarfs merging. In fact, the white dwarf mergers may be more common. More supernova research with Kepler will help astronomers on a quest to find out if different type Ia mechanisms result in some supernovae being brighter than others — which would throw a wrench into how they are used to measure the universe’s expansion.

“To get a better idea of constraining dark energy, we have to understand better how these type Ia supernovae are formed,” Rest said.

Another kind of supernova, the “core collapse” variety, happens when a massive star ends its life in an explosion. This includes “Type II” supernovae. These supernovae have a characteristic shockwave called the “shock breakout,” which was captured for the first time in optical light by Kepler. The Kepler Extra-Galactic Survey team, led by team member Peter Garnavich, an astrophysics professor at the University of Notre Dame in Indiana, spotted this shock breakout in 2011 Kepler data from a supernova called KSN 2011d, an explosion from a star roughly 500 times the size of our Sun. Surprisingly, the team did not find a shock breakout in a smaller type II supernova called KSN 2011a, whose star was 300 times the size of the Sun — but instead found the supernova nestled in a layer of dust, suggesting that there is diversity in type II stellar explosions, too.

Kepler data have revealed other mysteries about supernovae. The new study led by Rest in Nature Astronomy describes a supernova from data captured by Kepler’s extended mission, called K2, that reaches its peak brightness in just a little over two days, about 10 times less than others take. It is the most extreme known example of a “fast-evolving luminous transient” (FELT) supernova. FELTs are about as bright as the type Ia variety, but rise in less than 10 days and fade in about 30. It is possible that the star spewed out a dense shell of gas about a year before the explosion, and when the supernova happened, ejected material hit the shell. The energy released in that collision would explain the quick brightening.

Telescopes on Earth offer a lot of information about exploding stars, but only over short periods of time — and only when the Sun goes down and the sky is clear – so it’s hard to document the “before” and “after” effects of these explosions. Kepler, on the other hand, offers astronomers the rare opportunity to monitor single patches of sky continuously for months, like a car’s dashboard camera that is always recording. In fact, the primary Kepler mission, which ran from 2009 to 2013, delivered four years of observations of the same field of view, snapping a picture about every 30 minutes. In the extended K2 mission, the telescope is holding its gaze steady for up to about three months.

With ground-based telescopes, astronomers can tell the supernova’s color and how it changes with time, which lets them figure out what chemicals are present in the explosion. The supernova’s composition helps determine the type of star that exploded. Kepler, on the other hand, reveals how and why the star explodes, and the details of how the explosion progresses. Using the two datasets together, astronomers can get fuller pictures of supernovae behavior than ever before.

Kepler mission planners revived the telescope in 2013, after the malfunction of the second of its four reaction wheels — devices that help control the orientation of the spacecraft. In the configuration called K2, it needs to rotate every three months or so — marking observing “campaigns.” Members of the Kepler Extra-Galactic Survey made the case that in the K2 mission, Kepler could still monitor supernovae and other exotic, distant astrophysical objects, in addition to exoplanets.

The possibilities were so exciting that the Kepler team devised two K2 observing campaigns especially useful for coordinating supernovae studies with ground-based telescopes. Campaign 16, which began on Dec. 7, 2017, and ended Feb. 25, 2018,included 9,000 galaxies. There are about 14,000 in Campaign 17, which is just beginning now. In both campaigns, Kepler faces in the direction of Earth so that observers on the ground can see the same patch of sky as the spacecraft. The campaigns have excited a community of researchers who can advantage of this rare coordination between Kepler and telescopes on the ground.

A recent possible sighting got astronomers riled up on Super Bowl Sunday this year, even if they weren’t into the game. On that “super” day, the All Sky Automated Survey for SuperNovae (ASASSN) reported a supernova in the same nearby galaxy Kepler was monitoring. This is just one of many candidate events that scientists are excited to follow up on and perhaps use to better understand the secrets of the universe.

A few more supernovae may come from NASA’s Transiting Exoplanet Survey Satellite, (TESS) which is expected to launch on April 16. In the meantime, scientists will have a lot of work ahead of them once they receive the full dataset from K2’s supernova-focused campaigns.

“It will be a treasure trove of supernova information for years to come,” Tucker said.

Ames manages the Kepler and K2 missions for NASA’s Science Mission Directorate. NASA’s Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.
Led overall by researchers at Aix-Marseille Université in France using NASA's Kepler Space Telescope, Nature Astronomy publishes observations of what may be a new exoplanet named K2-229b, whose attributes may resemble the planet of Mercury (hot, metallic, and dense).