15 Trianguli

15 Trianguli is a suspected variable star located in the northern constellation Triangulum, with an apparent magnitude of 5.4^[2] making it faintly visible to the naked eye under ideal conditions, although it is suspected of being an irregular variable with a range of 0.14 magnitudes.^[5] The star is situated about 480 light years^[1] away but is approaching with a heliocentric radial velocity of −8.646 km/s.^[6]

15 Trianguli

Location of 15 Trianguli (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Triangulum
Right ascension	02h 35m 46.821s[1]
Declination	+34° 41′ 15.18″[1]
Apparent magnitude (V)	5.396[2]
Characteristics
Evolutionary stage	AGB[3]
Spectral type	M3 III[2][4]
Variable type	suspected[5]
Astrometry
Radial velocity (Rv)	−8.646±2.407[6] km/s
Proper motion (μ)	RA: 26.689±0.361[1] mas/yr Dec.: −48.894±0.233[1] mas/yr
Parallax (π)	4.8075±0.2721 mas[1]
Distance	680 ± 40 ly (210 ± 10 pc)
Details
Mass	1.689±0.084[2] M☉
Radius	118.453±5.923[2] R☉
Luminosity	1,668[7] L☉
Surface gravity (log g)	0.489[8] cgs
Temperature	3,572[8] K
Metallicity [Fe/H]	0.08[8] dex
Other designations
15 Trianguli, NSV 866, AG+34°259, BD+34°469, GC 3103, HD 16058, HIP 12086, HR 750, SAO 55687
Database references
SIMBAD	data

15 Trianguli has a stellar classification of M3 III.^[2][4] It has 1.7 times the mass of the Sun and 118 times the radius of the Sun.^[2] It has an effective temperature of 3,572 K^[8] and shines at 1,668 times the luminosity of the Sun^[7] from its photosphere, giving it an orange glow. It is an asymptotic giant branch star, which means it is fusing hydrogen and helium in separate shells around an inert carbon core.^[3]