Tau3 Serpentis
Star in the constellation Serpens
From Wikipedia, the free encyclopedia
Tau3 Serpentis, Latinized from Ï3 Serpentis, is a giant star in the constellation of Serpens. It has an apparent visual magnitude of approximately 6.11,[2] which is bright enough to be dimly visible to the naked eye under favorable viewing conditions. The distance to this star is approximately 358 light years based on parallax measurements, but it is drifting closer with a heliocentric radial velocity of â22 km/s.[6]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Serpens |
| Right ascension | 15h 35m 33.230s[1] |
| Declination | +17° 39â² 20.00â³[1] |
| Apparent magnitude (V) | 6.10[2] |
| Characteristics | |
| Spectral type | G8III:[3] |
| BâV color index | +0.975±0.006[2] |
| Astrometry | |
| Radial velocity (Rv) | â22.3±2.9[4] km/s |
| Proper motion (μ) | RA: â77.745 mas/yr[1] Dec.: â13.437 mas/yr[1] |
| Parallax (Ï) | 9.1014±0.0329 mas[1] |
| Distance | 358 ± 1 ly (109.9 ± 0.4 pc) |
| Absolute magnitude (MV) | +0.78[2] |
| Details[1] | |
| Mass | 2.703+0.107 â0.040 Mâ |
| Radius | 9.68+0.20 â0.19 Râ |
| Luminosity | 47.28+0.33 â0.31 Lâ |
| Surface gravity (log g) | 2.478±0.005 cgs |
| Temperature | 4,864±1 K |
| Age | 502+51 â69 Myr |
| Other designations | |
| Ï3 Ser, 15 Serpentis, BD+18°3044, FK5 3230, GC 20962, HD 139074, HIP 76337, HR 5795, SAO 101631, PPM 131527[5] | |
| Database references | |
| SIMBAD | data |
The stellar classification of this star is G8III:,[3] which matches a G-type giant star. However, the trailing colon ':' indicates some uncertainty in the classification. About 500 million years old and with 2.7 times the mass of the Sun, Tau3 Serpentis has expanded to 9.7 times the Sun's radius, and is radiating 47 times the luminosity of the Sun from its photosphere at an effective temperature of 4,864 K.[1]
