7 Trianguli
Star in the constellation Triangulum
From Wikipedia, the free encyclopedia
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.
 | |
| 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 | |
| Evolutionary stage | main sequence[1] |
| 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]
It was once designated Eta Trianguli by John Flamsteed and was included in his Atlas Coelestis, but the designation is now dropped.[14]
Together with δ Trianguli and γ Trianguli, it forms an optical (line-of-sight) triple.