HD 15920
Giant star in the constellation Cassiopeia
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HD 15920 is a single[7] star in the northern constellation of Cassiopeia. It has a yellow hue and is visible to the naked eye as a dim point of light with an apparent visual magnitude of 5.17.[1] This object is located at a distance of approximately 269 light years from the Sun based on parallax, but it is drifting closer with a radial velocity of −4 km/s.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Cassiopeia[1] |
| Right ascension | 02h 38m 02.03317s[2] |
| Declination | +72° 49′ 05.7106″[2] |
| Apparent magnitude (V) | 5.17[1] |
| Characteristics | |
| Evolutionary stage | red giant branch[2] |
| Spectral type | G8III[3] |
| B−V color index | +0.896±0.003[1] |
| Astrometry | |
| Radial velocity (Rv) | −3.81±0.12[2] km/s |
| Proper motion (μ) | RA: −27.072[2] mas/yr Dec.: +15.618[2] mas/yr |
| Parallax (π) | 12.1337±0.0717 mas[2] |
| Distance | 269 ± 2 ly (82.4 ± 0.5 pc) |
| Absolute magnitude (MV) | 0.70[1] |
| Details | |
| Mass | 2.55±0.68[4] M☉ |
| Radius | 10.26±0.73[5] R☉ |
| Luminosity | 64+6 −5[5] L☉ |
| Surface gravity (log g) | 2.91±0.11[4] cgs |
| Temperature | 5,104±148[5] K |
| Metallicity [Fe/H] | 0.02±0.05[4] dex |
| Age | 977+198 −164[4] Myr |
| Other designations | |
| BD+72°140, FK5 87, GC 3116, HD 15920, HIP 12273, HR 743, SAO 4694, GSC 04320-02109[6] | |
| Database references | |
| SIMBAD | data |
This object is an aging giant star with a stellar classification of G8III.[3] After exhausting the supply of hydrogen at its core, this star has cooled and expanded off the main sequence – at present it has ten times the girth of the Sun.[5] The star is around a billion years old with 2.6 times the mass of the Sun.[4] It is radiating 64 times the Sun's luminosity from its swollen photosphere at an effective temperature of 5,104 K.[5] HD 15920 is the most likely source for the X-ray emission detected at these coordinates.[8]