1 Trianguli

1 Trianguli, also known as HD 10407, is a star located in the northern constellation Triangulum. It has an apparent magnitude of 7.52,^[2] making it readily visible in binoculars but not to the naked eye. Gaia DR3 parallax measurements imply a distance of 723 light years^[1] and it is currently receding with a heliocentric radial velocity of 7 km/s.^[4] At its current distance 1 Trianguli's brightness is diminished by a quarter of a magnitudes due to interstellar dust^[12] and it has an absolute magnitude of +0.78.^[5] Even though it has a Flamsteed designation, 1 Trianguli is one of the 220 Flamsteed stars that are not in the Yale Bright Star Catalogue.^[13]

1 Trianguli

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Triangulum
Right ascension	01h 42m 05.92475s[1]
Declination	+29° 30′ 21.8431″[1]
Apparent magnitude (V)	7.52±0.01[2]
Characteristics
Evolutionary stage	main sequence star[1]
Spectral type	A2 V[3]
B−V color index	+0.06[2]
Astrometry
Radial velocity (Rv)	7±4.5[4] km/s
Proper motion (μ)	RA: −10.545 mas/yr[1] Dec.: −0.288 mas/yr[1]
Parallax (π)	4.5114±0.0515 mas[1]
Distance	723 ± 8 ly (222 ± 3 pc)
Absolute magnitude (MV)	+0.78[5]
Details
Mass	2.36+0.34 −0.30[6] M☉
Radius	2.69±0.14[7] R☉
Luminosity	52+1.5 −2.2[1] L☉
Surface gravity (log g)	3.90[8] cgs
Temperature	9,305+145 −192[6] K
Metallicity [Fe/H]	−0.02[8] dex
Age	371±23[9][10] Myr
Other designations
1 Trianguli, AG+29°220, BD+28°282, GC 2068, HD 10407, HIP 7948, SAO 74880, GSC 01762-00704[11]
Database references
SIMBAD	data

1 Trianguli has a stellar classification of A2 V,^[3] indicating that it is an ordinary A-type main-sequence star. It has 2.36 times the mass of the Sun^[6] and 2.69 times the Sun's radius.^[7] It radiates 52 times the luminosity of the Sun^[1] from its photosphere at an effective temperature of 9,305 K,^[6] giving it a white hue. It has a near solar metallicity at [Fe/H] = −0.02^[8] and 1 Trianguli is estimated to be 371 million years old.^[9][10]