HD 104555

HD 104555, also known as HR 4595, is a star located in the southern circumpolar constellation Octans. It has an apparent magnitude of 6.02,^[2] allowing it to be faintly visible to the naked eye. Based on parallax measurements from Gaia Data Release 3, it is estimated to be 336 light years distant.^[1] It appears to be receding from the Solar System, having a heliocentric radial velocity of 17.1 km/s.^[6]

HD 104555

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Octans
Right ascension	12h 02m 20.23931s[1]
Declination	−85° 37′ 54.3264″[1]
Apparent magnitude (V)	6.02±0.01[2]
Characteristics
Evolutionary stage	horizontal branch[3]
Spectral type	K3 III[4]
U−B color index	+1.54[5]
B−V color index	+1.29[5]
Astrometry
Radial velocity (Rv)	17.1±0.4[6] km/s
Proper motion (μ)	RA: −57.259 mas/yr[1] Dec.: +1.452 mas/yr[1]
Parallax (π)	9.7144±0.0241 mas[1]
Distance	335.7 ± 0.8 ly (102.9 ± 0.3 pc)
Absolute magnitude (MV)	+0.78[7]
Details
Mass	2.18+0.02 −0.01[8] M☉
Radius	9.82+1.95 −0.92[8] R☉
Luminosity	59.8[9] L☉
Temperature	4,497±122[10] K
Metallicity [Fe/H]	−0.06+0.11 −0.08[8] dex
Rotational velocity (v sin i)	<1[11] km/s
Age	955+68 −42[8] Myr
Other designations
12 G. Octantis[12], CPD−84°371, FK5 3983, GC 16449, HD 104555, HIP 58697, HR 4595, SAO 258632, WDS J12023-8538A[13]
Database references
SIMBAD	data

This is an evolved, orange hued giant star with a stellar classification of K3 III.^[4] It is currently on the horizontal branch,^[3] generating energy via helium fusion at its core. It has twice the mass of the Sun but at 955 million years old, it has expanded to 9.82 times its girth.^[8] It radiates 60 times the luminosity of the Sun^[9] from its photosphere at an effective temperature of 4,497 K.^[10] HD 10455 has an iron abundance 12% below solar levels, making it slightly metal deficient.^[8] Like most giants, it spins slowly, having a projected rotational velocity lower than 1 km/s.^[11]

HIP 58713 is an 8th magnitude co-moving star located 24.8″ away along a position angle of 146°.^[14] It is a main sequence star with a spectral class of F8, and is estimated to be around the same distance as HD 104555.^[15]