Delta2 Tauri
Star in the constellation Taurus
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Delta2 Tauri (δ2 Tauri) is a solitary,[10] white-hued star in the zodiac constellation of Taurus. Based upon an annual parallax shift of 20.21 mas as seen from Earth,[1] it is located roughly 161 light years distant from the Sun. It is separated from δ1 Tauri by 0.3° on the sky[11] and is faintly visible to the naked eye with an apparent visual magnitude of +4.80.[2] The star is considered a member of the Hyades cluster.[12]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 24m 05.75985s[1] |
| Declination | +17° 26′ 38.8583″[1] |
| Apparent magnitude (V) | +4.80[2] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | A2 Vs[3] |
| U−B color index | +0.12[2] |
| B−V color index | +0.15[2] |
| Astrometry | |
| Radial velocity (Rv) | +37.1[4] km/s |
| Proper motion (μ) | RA: +108.16[1] mas/yr Dec.: −34.66[1] mas/yr |
| Parallax (π) | 20.21±0.40 mas[1] |
| Distance | 161 ± 3 ly (49.5 ± 1.0 pc) |
| Absolute magnitude (MV) | +1.62[5] |
| Details | |
| Mass | 1.79[6] M☉ |
| Radius | 1.8[7] R☉ |
| Luminosity | 27[8] L☉ |
| Surface gravity (log g) | 4.15[4] cgs |
| Temperature | 7,997[4] K |
| Metallicity [Fe/H] | +0.14[4] dex |
| Rotational velocity (v sin i) | 42[4] km/s |
| Age | 449[6] Myr |
| Other designations | |
| δ2 Tau, 64 Tauri, BD+17°714, HD 27819, HIP 20542, HR 1380, SAO 93907[9] | |
| Database references | |
| SIMBAD | data |
At the estimated age of 449 million years,[6] this is an A-type main-sequence star with a stellar classification of A2 Vs,[3] where the 's' suffix indicates narrow (sharp) absorption lines. It has 1.8[6] times the mass of the Sun and about 1.8[7] times the Sun's radius. The star is radiating 27[8] times the Sun's luminosity from its photosphere at an effective temperature of 7,997 K.[4]
δ2 Tauri is a source of X-ray emission with a luminosity of 101.1×1020 W. Since A-type stars are not normally a source of X-rays, this emission may be coming from an unknown companion or from a line of sight source.[13]