HD 10550

HD 10550 is a single^[8] star in the equatorial constellation of Cetus. It is a faint star but visible to the naked eye with an apparent visual magnitude of 4.98.^[2] Based upon an annual parallax shift of 2.9564 mas,^[1] it is located around 1,100 light years from the Sun. The star is moving closer with a heliocentric radial velocity of −33 km/s.^[1] It has a high peculiar velocity of 72.7+5.7
−4.3 km/s and may be a runaway star.^[9]

HD 10550

Observation data Epoch J2000      Equinox J2000
Constellation	Cetus
Right ascension	01h 42m 43.51077s[1]
Declination	–03° 41′ 24.7210″[1]
Apparent magnitude (V)	4.98[2]
Characteristics
Spectral type	K2/3 III CN II[3]
B−V color index	1.378±0.003[2]
Astrometry
Radial velocity (Rv)	−33.28±0.15[1] km/s
Proper motion (μ)	RA: −8.989[1] mas/yr Dec.: −33.238[1] mas/yr
Parallax (π)	2.9564±0.1730 mas[1]
Distance	1,100 ± 60 ly (340 ± 20 pc)
Absolute magnitude (MV)	−2.82[2]
Details
Radius	77[4] R☉
Luminosity	2,537.45[2] L☉
Surface gravity (log g)	1.83[5] cgs
Temperature	4,110[5] K
Metallicity [Fe/H]	−0.12[5] dex
Rotational velocity (v sin i)	10[6] km/s
Other designations
BD−04° 260, FK5 1049, HD 10550, HIP 7999, HR 500, SAO 129465[7]
Database references
SIMBAD	data

The stellar classification of this star is K2/3 III CN II,^[3] showing the spectrum of an evolved K-type giant star with an overabundance of CN in the atmosphere. The measured angular diameter of this star, after correction for limb darkening, is 2.11±0.04 mas.^[10] At the estimated distance of this star, this yields a physical size of about 77 times the radius of the Sun.^[4] The star is radiating around 2,537^[2] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,110 K.^[5]