Groombridge 1830

Groombridge 1830
Groombridge 1830 (circled in red) in Ursa Major

Detailed position of HR 4550 ( = Groombridge 1830; bottom-left edge) related to χ UMa and ψ UMa
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Major
Right ascension 11h 52m 58.76734s
Declination +37° 43 07.2541
Apparent magnitude (V) 6.44
Characteristics
Evolutionary stage main sequence
Spectral type K1V Fe−1.5
U−B color index +0.16
B−V color index +0.75
Variable type Suspected
Astrometry
Radial velocity (Rv)−98.05±0.12 km/s
Proper motion (μ) RA: +4,002.7 mas/yr
Dec.: −5,817.8 mas/yr
Parallax (π)109.0296±0.0197 mas
Distance29.914 ± 0.005 ly
(9.172 ± 0.002 pc)
Absolute magnitude (MV)6.64
Details
Mass0.63±0.02 M
Radius0.586±0.004 R
Luminosity0.221±0.005 L
Surface gravity (log g)4.702±0.015 cgs
Temperature5,174±32 K
Metallicity [Fe/H]−1.26±0.07 dex
Rotation32.2
Rotational velocity (v sin i)0.5 km/s
Age4.7–5.3 Gyr
Other designations
Groombridge 1830, Argelander's Star, CF UMa, BD+38 2285, FK5 1307, GJ 451, HD 103095, HIP 57939, HR 4550, SAO 62738, LHS 44, LTT 13276, PLX 2745
Database references
SIMBADdata

Groombridge 1830 is a star 29.9 light-years away in the constellation Ursa Major. With an apparent magnitude of 6.4, it is near the limit of naked eye visibility under ideal conditions. It has a low metallicity and is thought to be a superflare star.