Tau2 Serpentis, Latinized from τ2 Serpentis, is a star in the constellation of Serpens, located approximately 480 light-years from the Sun.[1] It is a challenge to view with the naked eye, having an apparent visual magnitude of 6.22.[2] The star is drifting closer with a radial velocity of −19 km/s.[2]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Serpens |
| Right ascension | 15h 32m 09.67495s[1] |
| Declination | +16° 03′ 22.2056″[1] |
| Apparent magnitude (V) | 6.22[2] |
| Characteristics | |
| Spectral type | B9V[3] |
| U−B color index | −0.23[4] |
| B−V color index | −0.038±0.005[2] |
| Astrometry | |
| Radial velocity (Rv) | −19.3±2.7[2] km/s |
| Proper motion (μ) | RA: −2.92[5] mas/yr Dec.: +6.48[5] mas/yr |
| Parallax (π) | 6.7936 ± 0.0928 mas[1] |
| Distance | 480 ± 7 ly (147 ± 2 pc) |
| Absolute magnitude (MV) | +0.44[2] |
| Details | |
| Mass | 2.89±0.08[6] M☉ |
| Radius | 2.7[7] R☉ |
| Luminosity | 96.4+15.3 −12.6[6] L☉ |
| Temperature | 10,839+60 −50[6] K |
| Rotational velocity (v sin i) | 154[6] km/s |
| Age | 278[8] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This object is a late B-type main-sequence star with a stellar classification of B9V.[3] It is a probable Lambda Boötis star.[2][10] The star is 278[8] million years old and is spinning with a projected rotational velocity of 154 km/s.[6] It has nearly three times the mass and radius of the Sun.[6][7] Tau2 Serpentis is radiating 96[6] times the Sun's luminosity from its photosphere at an effective temperature of 10,839 K.[6]
There is evidence of a possible companion, which is contributing about 15% to the total emission of the system.[11]