Gamma Sextantis

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
Spectral type A0/1 V[4] (A1 V + A4 V)[5]
U−B color index +0.06[2]
B−V color index +0.04[2]
Astrometry
Radial velocity (Rv)+12[6] 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]
Distance280 ± 10 ly
(85 ± 5 pc)
Absolute magnitude (MV)+0.43[7]
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
Mass2.60[8] M☉
Luminosity57[9] L☉
Surface gravity (log g)4.18±0.14[8] cgs
Temperature9,825±334[8] K
Rotational velocity (v sin i)134.6±1.4[10] km/s
Age401[8] Myr
Other designations
γ Sex, 8 Sextantis, BD−07° 2909, HD 85558, HIP 48437, HR 3909, SAO 137199.[11]
Database references
SIMBADdata

Gamma Sextantis, Latinized as γ Sextantis, is a binary star[12] 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.

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,[5] the brighter component A is an A-type main sequence star with a stellar classification of A1 V.[5] The fainter companion B has a classification of A4 V[5] with a magnitude of 6.0.[5] Their combined spectral matches a classification of A0/1 V[4] and their angular separation 0,4 arcseconds, so for the observation a telescope with at least 30 centimetres aperture is require.

There is a magnitude 12.28 companion star 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 μα = −29 mas/yr and μδ = +5 mas/yr.[13]

  1. ^ a b c d e f g Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Heintz1982 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1999 was invoked but never defined (see the help page).
  5. ^ a b c d e Cite error: The named reference Edwards1976 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Wilson1953 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference David2015 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Diaz2011 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).