Kappa Serpentis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Serpens |
| Right ascension | 15h 48m 44.37720s |
| Declination | +18° 08′ 29.6337″ |
| Apparent magnitude (V) | 4.09 |
| Characteristics | |
| Evolutionary stage | red giant branch |
| Spectral type | M0.5III |
| U−B color index | +1.95 |
| B−V color index | +1.62 |
| Astrometry | |
| Radial velocity (Rv) | −38.48 km/s |
| Proper motion (μ) | RA: −52.407 mas/yr Dec.: −88.419 mas/yr |
| Parallax (π) | 8.5231±0.1657 mas |
| Distance | 383 ± 7 ly (117 ± 2 pc) |
| Absolute magnitude (MV) | −1.25 |
| Details | |
| Mass | 2.7 M☉ |
| Radius | 71.31+1.42 −1.48 R☉ |
| Luminosity | 1,021±57 L☉ |
| Surface gravity (log g) | 1.96 cgs |
| Temperature | 3,863±39 K |
| Metallicity [Fe/H] | −0.30 dex |
| Other designations | |
| Gudja, κ Ser, 35 Ser, NSV 7269, BD+18 3074, FK5 584, HD 141477, HIP 77450, HR 5879, SAO 101752 | |
| Database references | |
| SIMBAD | data |
Kappa Serpentis, Latinised from κ Serpentis, is a single, red-hued star in the constellation Serpens, in its head (Serpens Caput). It has the proper name Gudja /ˈɡuːdʒə/ and the Flamsteed designation 35 Serpentis. This star is visible to the naked eye with an apparent visual magnitude of +4.09. It is located approximately 383 light years from the Sun, based on parallax, and is drifting closer with a radial velocity of −38 km/s.
This object is an aging red giant star with a stellar classification of M0.5III. After exhausting the supply of hydrogen at its core, the star cooled and expanded off the main sequence, and now has around 71 times the Sun's radius. It is radiating nearly 1,000 times the luminosity of the Sun from its photosphere at an effective temperature of 3,863 K. This is a suspected variable star. Although simple grading based on its colour and luminosity mark this star as possibly being on the asymptotic giant branch, a closer study places it as being towards the most luminous part of the red giant branch, before starting core helium fusion.