HD 191939

HD 191939

Location of HD 191939 in the night sky. The star is marked within the red diamond.
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Draco
Right ascension	20h 08m 5.75s[1]
Declination	+66° 51′ 2.1″[1]
Apparent magnitude (V)	8.971[2]
Characteristics
HD 191939
Evolutionary stage	main sequence
Spectral type	G8V[3]
Astrometry
Radial velocity (Rv)	+9.266±0.0018[1] km/s
Proper motion (μ)	RA: +150.256[1] mas/yr Dec.: −63.909[1] mas/yr
Parallax (π)	18.6247 ± 0.0253[1] mas
Distance	175.1 ± 0.2 ly (53.69 ± 0.07 pc)
Absolute magnitude (MV)	5.32
Details[3]
HD 191939
Mass	0.92 M☉
Radius	0.945 R☉
Luminosity (visual, LV)	0.69 L☉
Surface gravity (log g)	4.44 cgs
Temperature	5427 K
Metallicity [Fe/H]	−0.16 dex
Rotational velocity (v sin i)	0.6 km/s
Age	7±3 Gyr
Other designations
HIP 99175, TYC 4244-964-1, USNO-A2 1500-07227721, 2MASS J20080574+6651019, Gaia DR2 2248126315275354496, TOI 1339
Database references
SIMBAD	data
Exoplanet Archive	data
Extrasolar Planets Encyclopaedia	data

HD 191939 is a single yellow (G-type) main-sequence star, located approximately 175 light-years away in the constellation of Draco, taking its primary name from its Henry Draper Catalogue designation.

Characteristics[]

HD 191939 is a Sun-like G-type main-sequence star, likely older than the Sun and relatively depleted in metals.

Planetary system[]

In 2020, an analysis carried out by a team of astronomers led by astronomer Mariona Badenas-Agusti of the TESS project confirmed the existence of three gas giants,^[3] all smaller than Neptune, in orbit around HD 191939. Another non-transiting gas giant planet designated HD 191939 e was detected in 2021, along with a substellar object on a highly uncertain, 9 to 46 year orbit.^[4]