. The Radial Velocity, that is the speed at which the star is moving away/towards us is -28.20000 km/s with an error of about 4.20 km/s .
Luminosity is the amount of energy that a star pumps out and its relative to the amount that our star, the Sun gives out. The figure of 31.41 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.
Pi Serpentis has a spectral type of A3V. This means the star is a blue main sequence dwarf star. The star is 7,371.00 Parsecs from the Galactic Centre or terms of Light Years is 24,041.50 s. The star has a B-V Colour Index of 0.06 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 8,815 Kelvin.
Pi Serpentis Radius has been calculated as being 2.36 times bigger than the Sun.The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,640,332.56.km. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 2.39. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures. The star's Iron Abundance is 0.38 with an error value of 9.99 Fe/H with the Sun has a value of 1 to put it into context.
Pi Serpentis has an apparent magnitude of 4.82 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. If you used the 1997 Parallax value, you would get an absolute magnitude of 1.15 If you used the 2007 Parallax value, you would get an absolute magnitude of 1.12. Magnitude, whether it be apparent/visual or absolute magnitude is measured by a number, the smaller the number, the brighter the Star is. Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.
Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 18.42 which gave the calculated distance to Pi Serpentis as 177.07 light years away from Earth or 54.29 parsecs. It would take a spaceship travelling at the speed of light, 177.07 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.
In 2007, Hipparcos data was revised with a new parallax of 18.22 which put Pi Serpentis at a distance of 179.01 light years or 54.88 parsecs. It should not be taken as though the star is moving closer or further away from us. It is purely that the distance was recalculated.
The star's Galacto-Centric Distance is 7,371.00 Parsecs or 24,041.50 Light Years. The Galacto-Centric Distance is the distance from the star to the Centre of the Galaxy which is Sagittarius A*.
The source of the information if it has a Hip I.D. is from Simbad, the Hipparcos data library based at the University at Strasbourg, France. Hipparcos was a E.S.A. satellite operation launched in 1989 for four years. The items in red are values that I've calculated so they could well be wrong. Information regarding Metallicity and/or Mass is from the E.U. Exoplanets. The information was obtained as of 12th Feb 2017.
|Primary / Proper / Traditional Name||Pi Serpentis|
|Alternative Names||Pi. Ser, HD 143894, HIP 78554, HR 5972, 44 Serpentis, 44 Ser, BD+23 2886|
|Multiple Star System||No / Unknown|
|Star Type||main sequence Dwarf Star|
|Absolute Magnitude||1.15 / 1.12|
|Visual / Apparent Magnitude||4.82|
|Naked Eye Visible||Yes - Magnitudes|
|Right Ascension (R.A.)||16h 02m 17.69|
|Declination (Dec.)||+22° 48` 15.8|
|Galactic Latitude||46.78 degrees|
|Galactic Longitude||38.14 degrees|
|1997 Distance from Earth||18.42 Parallax (milliarcseconds)|
|177.07 Light Years|
|2007 Distance from Earth||18.22 Parallax (milliarcseconds)|
|179.01 Light Years|
|Galacto-Centric Distance||24,041.50 Light Years / 7,371.00 Parsecs|
|Proper Motion Dec.||23.60 ± 0.21 milliarcseconds/year|
|Proper Motion RA.||4.03 ± 0.26 milliarcseconds/year|
|Radial Velocity||-28.20 ± 4.20 km/s|
|Iron Abundance||0.38 ± 9.99 Fe/H|
