HD 138573

HD 138573 is a G-type main-sequence star in the constellation Serpens, class G5IV-V, roughly 98.4 light-years (30.2 parsecs) from Earth.^[7] This is a solar twin, with nearly the same characteristics of the Sun.^[4] It is more active than the Sun.^[8]

HD 138573

Observation data Epoch J2000      Equinox J2000
Constellation	Serpens
Right ascension	15h 32m 43.653s[1]
Declination	+10° 58′ 05.88″[1]
Apparent magnitude (V)	7.22[2]
Characteristics
Evolutionary stage	Main sequence[1]
Spectral type	G5 IV-V[3]
B−V color index	0.656[4]
Astrometry
Radial velocity (Rv)	−35.67±0.12[1] km/s
Proper motion (μ)	RA: −5.880 mas/yr[1] Dec.: 158.609 mas/yr[1]
Parallax (π)	33.1373±0.0240 mas[1]
Distance	98.43 ± 0.07 ly (30.18 ± 0.02 pc)
Absolute magnitude (MV)	4.82[4]
Details
Mass	0.98±0.01[5] M☉
Radius	1.038±0.021[1] R☉
Luminosity	0.994±0.005[1] L☉
Surface gravity (log g)	4.41±0.01[5] cgs
Temperature	5,740±3[5] K
Metallicity [Fe/H]	−0.024±0.003[5] dex
Rotational velocity (v sin i)	1.30[6] km/s
Age	6.50+0.29 −0.42[5] Gyr
Other designations
BD+11 2816, HD 138573, HIP 76114, SAO 101603[7]
Database references
SIMBAD	data

Mahdi et al. (2016) named the star the best solar twin candidate out of their dataset of around 2,800 candidates.^[4]

Sun comparison

Chart compares the Sun to HD 138573.

Identifier	J2000 Coordinates		Distance (ly)	Stellar Class	Temperature (K)	Metallicity (dex)	Age (Gyr)	Notes
	Right ascension	Declination
Sun	—	—	0.00	G2V	5,778	+0.00	4.6	[9]
HD 138573	15h 32m 43.7s	+10° 58′ 06″	98	G5IV-V	5,740	−0.024	6.5	[7][5][1]

See also

• HD 192699
• HD 210702