Gamma Sextantis

Gamma Sextantis, Latinized as γ Sextantis, is a binary star^[13] system in the equatorial constellation of Sextans. The combined apparent visual magnitude of the system is 5.05,^[2] which means it is faintly visible to the naked eye. The annual parallax shift is 11.75 mas,^[1] indicating a distance of around 280 light years.

γ Sextantis

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Sextans
Right ascension	09h 52m 30.43727s[1]
Declination	−08° 06′ 18.1269″[1]
Apparent magnitude (V)	5.05[2] (5.6 + 6.0)[3]
Characteristics
Evolutionary stage	main sequence[4]
Spectral type	A0/1 V[5] (A1 V + A4 V)[6]
U−B color index	+0.06[2]
B−V color index	+0.04[2]
Astrometry
Radial velocity (Rv)	+12[7] km/s
Proper motion (μ)	RA: −57.28[1] mas/yr Dec.: −49.26[1] mas/yr
Parallax (π)	11.75±0.63 mas[1]
Distance	280 ± 10 ly (85 ± 5 pc)
Absolute magnitude (MV)	+0.43[8]
Orbit[3]
Period (P)	77.55 yr
Semi-major axis (a)	0.383″
Eccentricity (e)	0.691
Inclination (i)	145.1°
Longitude of the node (Ω)	31.0°
Argument of periastron (ω) (secondary)	141.5°
Details
Mass	2.60[9] M☉
Radius	3.2[10] R☉
Luminosity	69[4] L☉
Surface gravity (log g)	4.18±0.14[9] cgs
Temperature	9,825±334[9] K
Rotational velocity (v sin i)	134.6±1.4[11] km/s
Age	401[9] Myr
Other designations
γ Sex, 8 Sextantis, BD−07°2909, HD 85558, HIP 48437, HR 3909, SAO 137199.[12]
Database references
SIMBAD	data

The two components orbit each other with a period of 77.55 years and a high eccentricity of 0.691. The orbital plane is inclined by 145.1° to the line of sight from the Earth.^[1] With a visual magnitude of 5.6,^[6] the brighter component Gamma Sextantis A is an A-type main sequence star with a stellar classification of A1 V.^[6] The fainter companion Gamma Sextantis B has a classification of A4 V^[6] with a magnitude of 6.0.^[6] Their combined spectrum matches a classification of A0/1 V^[5] . Their angular separation 0.4 arcseconds, so observation with a telescope requires a diameter of at least 30 centimeters.

There is a magnitude 12.28 companion star Gamma Sextantis C at an angular separation of 36.9 arc seconds along a position angle of 333°, as of 2000. This separation has increased from 30.0 arc seconds in 1834. The proper motion of this star differs from the Gamma Sextantis AB system, having components μ_α = −29 mas/yr and μ_δ = +5 mas/yr.^[14]