Gamma Circini

γ Circini
Location of y Circini (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Circinus
Right ascension 15h 23m 22.64294s[1]
Declination −59° 19′ 14.8131″[1]
Apparent magnitude (V) 4.51[2] (4.94 + 5.73)[3]
Characteristics
Spectral type B5 IV[4] + F8 V[2]
Variable type Be[5]
Astrometry
Radial velocity (Rv)16.90±1.78[6] km/s
Proper motion (μ) RA: −12.97[1] mas/yr
Dec.: −34.24[1] mas/yr
Parallax (π)7.27 ± 0.81 mas[1]
Distanceapprox. 450 ly
(approx. 140 pc)
Absolute magnitude (MV)−1.18[7]
Orbit[4]
Period (P)258 yr
Semi-major axis (a)2.576″
Eccentricity (e)0.931
Details
γ Cir A
Mass6.0±0.3[8] M☉
Temperature15,135[9] K
Age63.1±19.6[8] Myr
γ Cir B
Temperature4,786[9] K
Other designations
γ Cir, CPD−58° 5908, HIP 75323, HR 5704, SAO 242463[10]
γ Cir A: HD 136415
γ Cir B: HD 136416
Database references
SIMBADγ Cir AB
γ Cir A
γ Cir B

Gamma Circini, Latinized from γ Circini, is a star system in the constellation Circinus. It was noted as a double star by Herschel in 1835, who estimated the separation as 1 arc second.[11] It is visible to the naked eye with an apparent visual magnitude of 4.51.[2] Based upon an annual parallax shift of 7.27 mas,[1] it is about 450 light-years away.

A light curve for Gamma Circini, plotted from TESS data[12]

This is a wide binary star system and may even be a triple star.[9] The two visible components orbit each other with a preliminary estimated period of 258 years and a large eccentricity of 0.931.[4] As of 2014, the visible components have an angular separation of 0.80 arc seconds on a position angle of 359°.[3]

The primary star, component A, is a B-type subgiant star with a stellar classification of B5 IV.[4] Based upon isochrone curve fitting it is hypothesized to be a pair of matching B5 stars,[9] and is a Be variable with an uncertain maximum.[5] It has an effective temperature of 15,135[9] K and an estimated mass six[8] times that of the Sun. The companion, component B, is an F-type main-sequence star with a stellar classification of F8 V.[2] It has an effective temperature of 4,786[9] K.

  1. ^ a b c d e f 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 Buscombe1971 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Mason2014 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Malkov2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Kazarovets1999 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference deBruijne2012 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 Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  9. ^ a b c d e f Cite error: The named reference Parsons2004 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Carette1995 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).