72 Tauri
Star in the constellation of Taurus
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72 Tauri (abbreviated 72 Tau) is a possible binary star in the zodiac constellation of Taurus. It is faintly visible to the naked eye with an apparent visual magnitude of +5.5, although only 0.29° from the brighter υ Tauri. Based upon an annual parallax shift of 7.9 mas seen from Earth, it is around 410 light years from the Sun.
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 27m 17.4508s[1] |
| Declination | +22° 59′ 46.778″[1] |
| Apparent magnitude (V) | 5.514[2] |
| Characteristics | |
| Evolutionary stage | main sequence[1] |
| Spectral type | B7V[3] |
| U−B color index | −0.48[4] |
| B−V color index | −0.10[4] |
| Astrometry | |
| Radial velocity (Rv) | 32.2±1.1[5] km/s |
| Proper motion (μ) | RA: −1.409[1] mas/yr Dec.: −13.722[1] mas/yr |
| Parallax (π) | 7.9390±0.398 mas[1] |
| Distance | 410 ± 20 ly (126 ± 6 pc) |
| Absolute magnitude (MV) | +0.21[6] |
| Details | |
| Mass | 3.47[1] M☉ |
| Radius | 2.8[1] R☉ |
| Luminosity | 185[1] L☉ |
| Surface gravity (log g) | 3.97[1] cgs |
| Temperature | 12,689[1] K |
| Rotational velocity (v sin i) | 115[7] km/s |
| Age | 38[8] Myr |
| Other designations | |
| υ2 Tau, 72 Tauri, BD+22°699, HD 28149, HIP 20789, HR 1399[9][10] | |
| Database references | |
| SIMBAD | data |
Properties
72 Tauri is a B-type main sequence star with a stellar classification of B7V.[3] With a mass of 3.48 M☉ and an estimated age of 38 million years,[8] it is 2.8 times the size of the Sun and 185 times its luminosity.[1]
Occasionally this star system is given the Bayer designation υ2 Tauri with υ Tauri, which is separated from it by 0.29° in the sky.[4] υ Tauri is a foreground star, the two are unrelated,[11] and although 72 Tauri lies near the Hyades open cluster, it is much further away.[1]
72 Tauri lies near the ecliptic and can be occulted by the moon. Observations of an occultation in 1985 showed that it was a binary star with the two components separated by 0.1″.[12] There has been no confirmation of this finding and other sources list the star as single.[13]