HD 194612

HD 194612 (HR 7812) is a solitary^[14] orange hued star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.9,^[2] making it visible to the naked eye under ideal conditions. Parallax measurements place it at a distance of 760 light years^[1] and it has a low heliocentric radial velocity of 0.3 km/s.^[6]

HD 194612

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Octans
Right ascension	20h 38m 18.6064s[1]
Declination	−81° 17′ 20.6261″[1]
Apparent magnitude (V)	5.89±0.01[2]
Characteristics
Evolutionary stage	RGB[3]
Spectral type	K5 III[4]
U−B color index	+2.02[5]
B−V color index	+1.71[5]
Astrometry
Radial velocity (Rv)	0.3±0.4[6] km/s
Proper motion (μ)	RA: +1.597 mas/yr[1] Dec.: −37.819 mas/yr[1]
Parallax (π)	4.3006±0.0707 mas[1]
Distance	760 ± 10 ly (233 ± 4 pc)
Absolute magnitude (MV)	−0.56[7]
Details
Mass	2.1[8] M☉
Radius	59.9[9] R☉
Luminosity	598±13[10] L☉
Surface gravity (log g)	0.99±0.02[3] cgs
Temperature	3941±122[9] K
Rotational velocity (v sin i)	2.3±1.2[11] km/s
Other designations
49 G. Octantis[12], CPD−81°906, GC 28578, HD 194612, HIP 101843, HR 7812, SAO 258864[13]
Database references
SIMBAD	data

This is a red giant with a stellar classification of K5 III,^[4] and Gaia DR3 stellar evolution models place it on the red giant branch.^[3] It has double the mass of the Sun^[8] and an enlarged radius of 59.9 R_☉^[9] due to its evolved status. It shines with a luminosity of 598 L_☉^[10] from its photosphere at an effective temperature of 3,941 K.^[9] Like many giants, HD 194612 has a comparatively modest projected rotational velocity, which is around 2.3 km/s.^[11]