7 Trianguli

7 Trianguli is a solitary^[11] star located in the northern constellation Triangulum. It has an apparent magnitude of 5.25,^[2] making it faintly visible to the naked eye under ideal conditions. The star is situated at distance of 360 light years^[1] but is approaching with a heliocentric radial velocity of −1.3 km/s,^[6] which is poorly constrained.

7 Trianguli

Location of 7 Trianguli (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Triangulum
Right ascension	02h 15m 56.2876s[1]
Declination	+33° 21′ 32.032″[1]
Apparent magnitude (V)	5.25±0.01[2]
Characteristics
Spectral type	A0 V[3] or B9.5 V[4]
U−B color index	−0.03[5]
B−V color index	−0.01[5]
Astrometry
Radial velocity (Rv)	−1.3±2[6] km/s
Proper motion (μ)	RA: −15.234[1] mas/yr Dec.: −32.711[1] mas/yr
Parallax (π)	9.0683±0.137 mas[1]
Distance	360 ± 5 ly (110 ± 2 pc)
Absolute magnitude (MV)	0.58[7]
Details
Mass	2.77[8] M☉
Radius	3.24±0.11[9] R☉
Luminosity	89.1+10.5 −8.1[9] L☉
Surface gravity (log g)	4.02±0.14[8] cgs
Temperature	10685±363[8] K
Rotational velocity (v sin i)	130[10] km/s
Age	283[8] Myr
Other designations
7 Trianguli, AG+33° 210, BD+32° 409, GC 2710, HD 13869, HIP 10559, HR 655, SAO 55397
Database references
SIMBAD	data

7 Trianguli has a stellar classification of A0 V^[3] or B9.5 V,^[4] depending on the study. At present it has 2.77 times the mass of the Sun^[8] and 3.24 times the radius of the Sun.^[9] It shines at 89.1 times the luminosity of the Sun^[9] from its photosphere at an effective temperature of 10,685 K,^[8] giving it a blueish white glow. 7 Trianguli is a young star, with an age of 283 million years^[8] and spins rapidly with a projected rotational velocity of 130 km/s.^[10] It has been classified as having a peculiar spectrum,^[12] but it is considered doubtful that it is actually a chemically peculiar star.^[13]

Together with δ Trianguli and γ Trianguli, it forms an optical (line-of-sight) triple.