Tau2 Serpentis
Star in the constellation Serpens
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Tau2 Serpentis, Latinized from Ï2 Serpentis, is a star in the constellation of Serpens, located approximately 480 light-years from the Sun.[2] It is a challenge to view with the naked eye, having an apparent visual magnitude of 6.22.[1] The star is drifting closer with a radial velocity of â19 km/s.[1]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Serpens[1] |
| Right ascension | 15h 32m 09.67495s[2] |
| Declination | +16° 03â² 22.2056â³[2] |
| Apparent magnitude (V) | 6.22[1] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | B9V[4] |
| UâB color index | â0.23[5] |
| BâV color index | â0.038±0.005[1] |
| Astrometry | |
| Radial velocity (Rv) | â19.3±2.7[1] km/s |
| Proper motion (μ) | RA: â2.92[6] mas/yr Dec.: +6.48[6] mas/yr |
| Parallax (Ï) | 6.7936±0.0928 mas[2] |
| Distance | 480 ± 7 ly (147 ± 2 pc) |
| Absolute magnitude (MV) | +0.44[1] |
| Details | |
| Mass | 2.82[7] Mâ |
| Radius | 2.70[7] Râ |
| Luminosity | 91[7] Lâ |
| Surface gravity (log g) | 4.02[7] cgs |
| Temperature | 10,839[7] K |
| Rotational velocity (v sin i) | 154[3] km/s |
| Age | 278[8] Myr |
| Other designations | |
| Ï2 Ser, 12 Serpentis, BD+16°2797, GC 20880, HD 138527, HIP 76069, HR 5770, SAO 101600, PPM 131484[9] | |
| Database references | |
| SIMBAD | data |
This object is a late B-type main-sequence star with a stellar classification of B9V.[4] It is a probable Lambda Boötis star.[1][10] The star is 278[8] million years old and is spinning with a projected rotational velocity of 154 km/s.[3] It has nearly three times the mass and radius of the Sun. Tau2 Serpentis is radiating 91 times the Sun's luminosity from its photosphere at an effective temperature of 10,839 K.[7]
There is evidence of a possible companion, which is contributing about 15% to the total emission of the system.[11]