HD 90089

HD 90089 (HR 4084; Gliese 392.1) is a star located in the northern circumpolar constellation Camelopardalis. With an apparent magnitude of 5.25,^[3] it is faintly visible to the naked eye under ideal conditions. This star is located relatively close at a distance of 75 light years,^[10] but is drifting away at a rate of almost 8 km/s.^[7]

HD 90089

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Camelopardalis[1]
Right ascension	10h 31m 04.7079s[2]
Declination	+82° 33′ 31.146″[2]
Apparent magnitude (V)	5.252±0.009[3]
Characteristics
Evolutionary stage	main sequence[4]
Spectral type	F4 V kF2 mF2[5]
U−B color index	−0.05[6]
B−V color index	+0.37[6]
Astrometry
Radial velocity (Rv)	+7.9±0.9[7] km/s
Proper motion (μ)	RA: −86.133[2] mas/yr Dec.: +19.832[2] mas/yr
Parallax (π)	43.4367±0.5983 mas[2]
Distance	75 ± 1 ly (23.0 ± 0.3 pc)
Absolute magnitude (MV)	3.60[8]
Details
Mass	1.29[9] M☉
Radius	1.40+0.03 −0.06[10] R☉
Luminosity	3.36±0.02[10] L☉
Surface gravity (log g)	4.43±0.14[9] cgs
Temperature	6,602+159 −69[10] K
Metallicity [Fe/H]	−0.26[3] dex
Rotational velocity (v sin i)	56.2[3] km/s
Age	1.074[9] Gyr
Other designations
BD+83°297, FK5 911, GJ 392.1, HD 90089, HIP 51502, HR 4084, SAO 1714, WDS J10311+8234A
Database references
SIMBAD	data

HD 90089 is an F4 main-sequence star with the calcium K-line and metallic lines of an F2 star.^[5] Although the spectral type is of a form that would indicate an Am star, it is not listed in any of the major catalogues of chemically peculiar stars.^[11] At present it has 1.29 times the mass of the Sun^[9] and 1.4 times its radius. It radiates at 3.36 times the luminosity of the Sun from its photosphere at an effective temperature of 6,602 K,^[10] which gives it a yellowish-white hue.

HD 90089's exact age depends on the method, with its X-ray luminosity giving it a young age of only 300 million years.^[3] David et al. gave it an age of 1.1 billion years,^[9] significantly older than the previous solution; it spins rapidly with a projected rotational velocity of 56.2 km/s,^[3] and has an M0 companion separated 13" away^[12] and at approximately the same distance.^[13]

An infrared excess has been detected around this star, most likely indicating the presence of a circumstellar disk at a radius of 145 AU. The temperature of this dust is 30 K.^[3]