HD 87816
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Vela |
| Right ascension | 10h 06m 07.21043s |
| Declination | −52° 11′ 16.5788″ |
| Apparent magnitude (V) | 6.499±0.009 |
| Characteristics | |
| Evolutionary stage | Red clump |
| Spectral type | K1III |
| B−V color index | 0.986 |
| Astrometry | |
| Radial velocity (Rv) | 4.7±0.4 km/s |
| Proper motion (μ) | RA: −55.682 mas/yr Dec.: +16.413 mas/yr |
| Parallax (π) | 7.4825±0.0196 mas |
| Distance | 436 ± 1 ly (133.6 ± 0.4 pc) |
| Absolute magnitude (MV) | +0.876±0.013 |
| Details | |
| Mass | 2.41±0.10 M☉ |
| Radius | 9.0±0.2 R☉ |
| Luminosity | 45±1 L☉ |
| Surface gravity (log g) | 2.860±0.096 cgs |
| Temperature | 4,989±46 K |
| Metallicity [Fe/H] | +0.139±0.035 dex |
| Other designations | |
| R Vel (obsolete), CD−51°4471, HD 87816, HIP 49477, HR 3978, TYC 8194-294-1 | |
| Database references | |
| SIMBAD | data |
HD 87816 is a star in the constellation Vela. With an apparent magnitude of 6.499, it is very close to the average threshold for naked eye visibility, and can only be viewed from sufficiently dark skies, far from light pollution. Based on parallax measurements, it lies at a distance of 436 light-years. It is moving away from the Solar System at a velocity of 4.7 km/s.
The spectrum of this star matches a spectral class of K1III, with the luminosity class III indicating it is a giant star that has exhausted the hydrogen at its core. It is now fusing helium, being in the evolutionary stage known as the horizontal branch. The star has 2.4 times the Sun's mass, having grown to a radius 9.0 times the radius of the Sun. It shines with 45 times the Sun's luminosity at an effective temperature of 4,989 K. The temperature gives it the orange hue typical of K-type stars.
HD 87816 was once believed to be a variable star and received the variable-star designation R Velorum, but it is now considered a constant star.