7 Tauri

7 Tauri is a multiple star in the northern constellation of Taurus. It has a combined apparent visual magnitude of 5.95,^[10] so, according to the Bortle scale, it is faintly visible from suburban skies at night. Measurements made with the Gaia spacecraft show an annual parallax shift of 5.5 mas, which is equivalent to a distance of around 593 light years from the Sun.

7 Tauri

Observation data Epoch J2000      Equinox J2000
Constellation	Taurus
A
Right ascension	03h 34m 26.629s[1]
Declination	+35° 27′ 51.86″[1]
Apparent magnitude (V)	6.58[2]
B
Right ascension	03h 34m 26.633s[3]
Declination	+35° 27′ 52.17″[3]
Apparent magnitude (V)	6.84[2]
Characteristics
A
Spectral type	A3V[4]
B−V color index	+0.13[4]
B
Spectral type	A3V[4]
B−V color index	+0.13[4]
Astrometry
Radial velocity (Rv)	+28.1[5] km/s
Proper motion (μ)	RA: +9.908 mas/yr[1] Dec.: −28.201 mas/yr[1]
Parallax (π)	5.4993±0.0587 mas[1]
Distance	593 ± 6 ly (182 ± 2 pc)
Absolute magnitude (MV)	+0.5/+0.6[4]
Orbit[6]
Period (P)	522.16 yr
Semi-major axis (a)	0.625″
Eccentricity (e)	0.679
Details
A
Mass	2.5[4] M☉
Radius	9.0[7] R☉
Luminosity	52[7] L☉
Temperature	8,551[8] K
B
Mass	2.5[4] M☉
Other designations
7 Tau, BD+23°473, HD 22091, HIP 16664, HR 1086[9]
Database references
SIMBAD	data

7 Tauri is a binary star with two nearly equal components about 0.7″ apart, designated as A and B. The spectrum of each star matches a stellar classification of A7V.^[4] 22″ away is a 10th-magnitude star, component C, which is itself a spectroscopic binary. In the past, these stars had been treated as a single system, but they are now known to have different proper motions and somewhat different distances.^[4]