HD 7977

HD 7977 (also designated as TYC 4034-1077-1 or USNO-A2 1500-01356484) is a G-type main-sequence star located in the constellation of Cassiopeia, around 246.9 light-years away from Earth. HD 7977 is notable for its close flyby of the Solar System 2.8 million years ago.^[4] Its flyby may have taken it close enough to the Sun that it penetrated deep into the Oort Cloud and disturbed the population of Oort Cloud bodies and long-period comets there.^[5] Its mass is equivalent to 1.07 times the Sun's mass.^[6]

Schematic view to scale of past and future close approaches to the Sun (up to Alpha Centauri), which includes HD 7977

HD 7977

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Cassiopeia
Right ascension	01h 20m 31.596s[1]
Declination	+61° 52′ 57.01″[1]
Apparent magnitude (V)	9.04[2]
Characteristics
Evolutionary stage	main sequence[1]
Spectral type	G3[3]
Astrometry
Proper motion (μ)	RA: +0.144[1] mas/yr Dec.: +0.010[1] mas/yr
Parallax (π)	13.2118±0.0322 mas[1]
Distance	246.9 ± 0.6 ly (75.7 ± 0.2 pc)
Details
Mass	1.07[1] M☉
Radius	1.09[1] R☉
Luminosity	1.20[1] L☉
Surface gravity (log g)	4.35[1] cgs
Temperature	5,816[1] K
Metallicity [Fe/H]	−0.59[1] dex
Age	6.7[1] Gyr
Other designations
HD 7977, BD+61°250, SAO 11703
Database references
SIMBAD	data