Tau7 Serpentis
Star in the constellation Serpens
From Wikipedia, the free encyclopedia
Tau7 Serpentis, Latinized from τ7 Serpentis, is an A-type star in the constellation of Serpens, 174 light-years from the Earth. It has an apparent visual magnitude of approximately 5.804. It is a well-known Am star, a type of chemically peculiar star with unusually strong lines of heavier elements (metals) due to slow rotation and stratification of elements in the star's atmosphere.[10]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Serpens[1] |
| Right ascension | 15h 41m 54.7166s[2] |
| Declination | +18° 27′ 50.531″[2] |
| Apparent magnitude (V) | 5.8[3] |
| Characteristics | |
| Evolutionary stage | main sequence[2] |
| Spectral type | A8Vam[4] |
| U−B color index | +0.11[5] |
| B−V color index | +0.20[5] |
| R−I color index | +0.10[5] |
| Astrometry | |
| Radial velocity (Rv) | −31.38±0.12[2] km/s |
| Proper motion (μ) | RA: −61.654[2] mas/yr Dec.: +54.319[2] mas/yr |
| Parallax (π) | 18.7185±0.0408 mas[2] |
| Distance | 174.2 ± 0.4 ly (53.4 ± 0.1 pc) |
| Absolute magnitude (MV) | +2.18[1] |
| Details | |
| Mass | 1.8[6] M☉ |
| Radius | 1.8[6] R☉ |
| Luminosity | 11[6] L☉ |
| Surface gravity (log g) | 4.20[6] cgs |
| Temperature | 7,809[6] K |
| Metallicity [Fe/H] | −0.02[7] dex |
| Rotational velocity (v sin i) | 78[8] km/s |
| Age | 839[7] Myr |
| Other designations | |
| τ7 Ser, 22 Serpentis, BD+18°3059, GC 21111, HD 140232, HIP 76878, HR 5845, SAO 101686, PPM 131613, WDS J15419+1828AB[9] | |
| Database references | |
| SIMBAD | data |
