14 Trianguli

14 Trianguli (14 Tri), also known as HD 15656, is a spectroscopic binary^[14] located in the northern constellation Triangulum. It has an apparent magnitude of 5.14,^[2] making it faintly visible to the naked eye in ideal conditions. Gaia DR3 parallax measurements place the system 433 light years away,^[1] and it is currently approaching the Solar System with a heliocentric radial velocity of −37 km/s.^[5] At its current distance, 14 Tri's brightness is diminished by 0.21 magnitude due to interstellar dust.^[15] It has an absolute magnitude of −0.46.^[6]

14 Trianguli

Location of 14 Trianguli (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Triangulum
Right ascension	02h 32m 06.16977s[1]
Declination	+36° 08′ 50.1813″[1]
Apparent magnitude (V)	5.14±0.01[2]
Characteristics
Spectral type	K5 III[3]
U−B color index	+1.78[4]
B−V color index	+1.47[4]
Astrometry
Radial velocity (Rv)	−36.8±0.3[5] km/s
Proper motion (μ)	RA: +45.066 mas/yr[1] Dec.: +11.901 mas/yr[1]
Parallax (π)	7.5319±0.1060 mas[1]
Distance	433 ± 6 ly (133 ± 2 pc)
Absolute magnitude (MV)	−0.46[6]
Orbit[7]
Primary	14 Tri A
Companion	14 Tri B
Period (P)	6,257±73 d
Eccentricity (e)	0.22±0.04
Periastron epoch (T)	2,448,284±166 JD
Argument of periastron (ω) (secondary)	40±11°
Semi-amplitude (K1) (primary)	2.27±0.09 km/s
Details
Mass	1.85±0.09[8] M☉
Radius	38.66±1.18[9] R☉
Luminosity	325±17[9] L☉
Surface gravity (log g)	1.65[10] cgs
Temperature	3,991[9] K
Metallicity [Fe/H]	−0.16[11] dex
Rotational velocity (v sin i)	2.1±1.2[12] km/s
Other designations
14 Trianguli, AG+35°233, BD+35°497, FK5 1070, GC 3032, HD 15656, HIP 11784, HR 736, SAO 55635[13]
Database references
SIMBAD	data

The visible component is an evolved red giant with a stellar classification of K5 III. It has 1.85 times the mass of the Sun,^[8] but it has expanded to 39 times its girth. It radiates 325 times the luminosity of the Sun from its photosphere at an effective temperature of 3,991 K,^[9] giving it an orangish-red hue. 14 Tri is slightly metal-deficient with [Fe/H] = −0.16,^[11] and spins modestly with a projected rotational velocity of 2.1 km/s.^[12] This is a single-lined spectroscopic binary that completes an eccentric orbit within 17 years. The secondary star has not been detected visually or in the spectrum and is expected to be a low-mass red dwarf or white dwarf.^[7] 14 Tri may be part of the Wolf 630 moving group.^[16]