37 Cancri

37 Cancri is a star in the zodiac constellation of Cancer. It is a challenge to view with the naked eye, having an apparent magnitude of 6.54.^[2] The star is moving away from the Earth with a heliocentric radial velocity of +22 km/s, having come as close as 246 light-years some 2.7 million years ago.^[6]

37 Cancri

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Cancer
Right ascension	08h 38m 05.17248s[1]
Declination	+09° 34′ 28.6006″[1]
Apparent magnitude (V)	6.542[2]
Characteristics
Evolutionary stage	main sequence[3]
Spectral type	A1 V[4][5]
B−V color index	−0.010±0.006[6]
Astrometry
Radial velocity (Rv)	+22.1±2.2[6] km/s
Proper motion (μ)	RA: −28.271[1] mas/yr Dec.: −4.237[1] mas/yr
Parallax (π)	6.5093±0.0735 mas[1]
Distance	501 ± 6 ly (154 ± 2 pc)
Absolute magnitude (MV)	1.30[6]
Details
Mass	2.66±0.05[3] M☉
Radius	1.8[7] R☉
Luminosity	30.9+3.0 −2.7[2] L☉
Surface gravity (log g)	4.30[2] cgs
Temperature	9,830[2] K
Metallicity [Fe/H]	−0.21±0.13[2] dex
Rotational velocity (v sin i)	35.2±1.1[2] km/s
Other designations
37 Cnc, BD+10°1840, HD 73316, HIP 42353, HR 3412, SAO 116975[5]
Database references
SIMBAD	data

This is an ordinary A-type main-sequence star with a stellar classification of A1 V,^[4] which indicates it is generating energy through hydrogen fusion at its core. It is spinning with a projected rotational velocity of 35 km/s.^[2] The star has 2.7^[3] times the mass of the Sun and around 1.8^[7] times the Sun's radius. It is radiating 31 times the luminosity of the Sun from its photosphere at an effective temperature of 9,830 K.^[2]