GG Carinae is a binary star system in the southern constellation of Carina, abbreviated GG Car. It is a variable star with a brightness that fluctuates around an apparent visual magnitude of 8.67,[3] making it too faint to be visible to the naked eye. The distance to this system is approximately 8,000 light years based on parallax measurements.[2]

GG Carinae

A visual band light curve for GG Carinae, plotted from data published by Gosset et al. (1984)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Carina
Right ascension 10h 55m 58.915s[2]
Declination −60° 23′ 33.44″[2]
Apparent magnitude (V) 8.67[3] (8.4 to 8.9)[4]
Characteristics
Evolutionary stage Supergiant
Spectral type B0/2eq[5]
B−V color index 0.552±0.025[3]
Variable type Unique[4]
Astrometry
Proper motion (μ) RA: −6.966 mas/yr[2]
Dec.: 2.056 mas/yr[2]
Parallax (π)0.4079 ± 0.0185 mas[2]
Distance8,000 ± 400 ly
(2,500 ± 100 pc)
Absolute magnitude (MV)−6.21[6]
Orbit[6]
Period (P)31.01±0.01 d
Semi-major axis (a)0.61±0.03 AU
Eccentricity (e)0.50±0.03
Inclination (i)60±20°
Periastron epoch (T)2,452,069.36±1.30 JD
Argument of periastron (ω)
(secondary)
339.87+3.10
−3.06
°
Semi-amplitude (K1)
(primary)
48.57+2.04
−1.87
km/s
Details[6]
Supergiant
Mass24±M
Radius27+9
−7
 R
Luminosity1.8+1.0
−0.7
×105
 L
Temperature23,000±2,000 K
Companion
Mass7.2 M
Other designations
GG Car, CD−59°3425, CPD−59°2855, HD 94878, HIP 53444, SAO 251181, PPM 358340, WDS J10560-6024A[7]
Database references
SIMBADdata

This star was found to have a peculiar spectrum by W. P. Fleming in 1892,[8] matching the profile of a P Cygni star[9] with bright emission lines of hydrogen.[10] In 1930, the brightness of the star was found to be variable by W. E. Kruytbosch, who determined a period of 31.043±0.014 d and suggested it may be both an eclipsing binary and intrinsically variable.[11] This period was confirmed by D. Hoffleit in 1933.[9] A near infrared excess was detected in 1973, indicating a circumstellar dust shell.[12]

Analysis of the spectrum by C. A. Hernández and associates in 1981 suggested the star is surrounded by a thick, extended envelope that is concealing absorption lines formed in the stellar photosphere. They used measurements of radial velocity variations to estimate a period of 31.03 days.[13] In 1984, E. Gosset and associates used photoelectric photometry to find a period of 31.020 days, but were convinced by the data that the orbital period is twice that value, or 62.039 days.[1] GG Carinae was classified as a supergiant B[e] star by Henny Lamers and associates in 1998, based on properties similar to B[e] supergiants in the Magellanic Clouds.[14]

In 2004, M. A. Machado and associates used high resolution spectral measurements to confirm that this is a binary system with intrinsic variability.[15] M. Kraus detected an enriched abundance of carbon-13 (in the form of 13CO) in the stellar wind, confirming that this is an evolved B[e] supergiant rather than a pre-main-sequence star.[16] Kraus and associates in 2013 detected CO gas in a circumbinary ring, which was possibly placed there by the primary as a rapidly-spinning Be star.[17] Alternatively, it may have come via Roche lobe overflow from the secondary member of the system,[6] about which little is known.[17] Brightness variations related to the orbital period are thought to be due to mass transfer between the components during periastron.[6]

GG Carinae is almost certainly a member of the rich but faint open cluster ASCC 63, which is thought to have about 1,700 member stars. The cluster is calculated to be 18 million years old and 3,500 pc away.[18]

References

edit
  1. ^ a b Gosset, E.; et al. (March 1984), "Photoelectric photometry of the peculiar emission-line star GG Carinae", Astronomy and Astrophysics Supplement Series, 55: 411–424, Bibcode:1984A&AS...55..411G. Note: the bibcode page for this paper shows the wrong title.
  2. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  3. ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  4. ^ a b Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  5. ^ Lopes, D. F.; et al. (August 1992), "A spectroscopic study of luminous peculiar B-type stars", Astronomy and Astrophysics, 261: 482–492, Bibcode:1992A&A...261..482L.
  6. ^ a b c d e Porter, Augustus; et al. (March 2021), "GG Carinae: orbital parameters and accretion indicators from phase-resolved spectroscopy and photometry", Monthly Notices of the Royal Astronomical Society, 501 (4): 5554–5574, arXiv:2011.13858, Bibcode:2021MNRAS.501.5554P, doi:10.1093/mnras/staa3749.
  7. ^ "GG Car". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2022-08-15.
  8. ^ Fleming, M. (November 1892), "Stars having peculiar spectra", Astronomy and Astro-Physics, 11: 765–767, Bibcode:1892AstAp..11..765F. Listed as AGC 14965.
  9. ^ a b Hoffleit, Dorrit (July 1933), "A Search for Variable Light in Stars Having P Cygni Type Spectra", Harvard College Observatory Bulletin, 892: 19–22, Bibcode:1933BHarO.892...19H.
  10. ^ Merrill, Paul W.; Burwell, Cora G. (September 1933), "Catalogue and Bibliography of Stars of Classes B and A whose Spectra have Bright Hydrogen Lines", Astrophysical Journal, 78: 87, Bibcode:1933ApJ....78...87M, doi:10.1086/143490.
  11. ^ Kruytbosch, W. E. (August 1930), "Variability of the P Cygni-type star C.P.D. -59°2855", Bulletin of the Astronomical Institutes of the Netherlands, 6: 11, Bibcode:1930BAN.....6...11K.
  12. ^ Allen, D. A. (1973), "Near infra-red magnitudes of 248 early-type emission-line stars and related objects", Monthly Notices of the Royal Astronomical Society, 161 (2): 145–166, Bibcode:1973MNRAS.161..145A, doi:10.1093/mnras/161.2.145.
  13. ^ Hernández, C. A.; et al. (December 1981), "Further spectroscopic observations of GG Carinae", Publications of the Astronomical Society of the Pacific, 93: 747–751, Bibcode:1981PASP...93..747H, doi:10.1086/130920.
  14. ^ Lamers, Henny J. G. L. M.; et al. (December 1998), "An improved classification of B[e]-type stars", Astronomy and Astrophysics, 340: 117–128, Bibcode:1998A&A...340..117L.
  15. ^ Machado, M. A.; et al. (July 2004), Tovmassian, G.; Sion, E. (eds.), "Using High Resolution Data to Investigate the Variability of GG Carinae System", Compact Binaries in the Galaxy and Beyond, Proceedings of the conference held 17-22 November, 2003 in La Paz, Baja California Sur. IAU Colloquium 194, Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias), vol. 20, p. 239, Bibcode:2004RMxAC..20..239M.
  16. ^ Kraus, M. (January 2009), "The pre- versus post-main sequence evolutionary phase of B[e] stars. Constraints from 13CO band emission", Astronomy and Astrophysics, 494 (1): 253–262, arXiv:0901.0714, Bibcode:2009A&A...494..253K, doi:10.1051/0004-6361:200811020, S2CID 17577491.
  17. ^ a b Kraus, M.; et al. (January 2013), "Molecular emission from GG Carinae's circumbinary disk", Astronomy & Astrophysics, 549: A28, arXiv:1211.5149, Bibcode:2013A&A...549A..28K, doi:10.1051/0004-6361/201220442, S2CID 59034700, A28.
  18. ^ Sampedro, L.; et al. (2017), "A multimembership catalogue for 1876 open clusters using UCAC4 data", Monthly Notices of the Royal Astronomical Society, 470 (4): 3937, arXiv:1706.05581, Bibcode:2017MNRAS.470.3937S, doi:10.1093/mnras/stx1485.

Further reading

edit
  • Porter, Augustus; et al. (January 2022), "The circumbinary rings of GG Carinae: indications of disc eccentricity growth in the B[e] supergiant's atomic emission lines", Monthly Notices of the Royal Astronomical Society, 509 (2): 1720–1735, arXiv:2110.10779, Bibcode:2022MNRAS.509.1720P, doi:10.1093/mnras/stab3083.
  • Porter, Augustus; et al. (June 2021), "GG Carinae: discovery of orbital-phase-dependent 1.583-day periodicities in the B[e] supergiant binary", Monthly Notices of the Royal Astronomical Society, 503 (4): 4802–4814, arXiv:2103.09725, Bibcode:2021MNRAS.503.4802P, doi:10.1093/mnras/stab817.
  • Domiciano de Souza, A.; et al. (January 2015), "The circumstellar environment of the B[e] star GG Car: an interferometric modeling", New windows on massive stars: asteroseismology, interferometry, and spectropolarimetry, Proceedings of the International Astronomical Union, IAU Symposium, vol. 307, pp. 291–292, Bibcode:2015IAUS..307..291D, doi:10.1017/S1743921314006966.
  • Marchiano, P.; et al. (April 2012), "The spectroscopic orbits and physical parameters of GG Carinae", Astronomy & Astrophysics, 540: 9, Bibcode:2012A&A...540A..91M, doi:10.1051/0004-6361/201117715, A91.
  • Pereyra, Antonio; et al. (July 2011), "Hα spectropolarimetry of GG Car", Active OB stars: structure, evolution, mass loss, and critical limits, Proceedings of the International Astronomical Union, IAU Symposium, vol. 272, pp. 420–421, Bibcode:2011IAUS..272..420P, doi:10.1017/S174392131101101X.
  • Marchiano, Paula E.; et al. (July 2011), "The spectroscopic orbits and physical parameters of GG Car", Active OB stars: structure, evolution, mass loss, and critical limits, Proceedings of the International Astronomical Union, IAU Symposium, vol. 272, pp. 523–524, Bibcode:2011IAUS..272..523M, doi:10.1017/S1743921311011288.
  • Pereyra, A.; et al. (December 2009), "Hα spectropolarimetry of the B[e] supergiant GG Carinae", Astronomy and Astrophysics, 508 (3): 1337–1341, arXiv:0910.5569, Bibcode:2009A&A...508.1337P, doi:10.1051/0004-6361/200913250, S2CID 54751014.
  • Gosset, E.; et al. (December 1985), "Radial velocities along the light curve of the peculiar emission-line star GG Carinae.", Astronomy and Astrophysics, 153: 71–78, Bibcode:1985A&A...153...71G.
  • Chen, K. -Y.; et al. (February 1983), "Photoelectric photometry of GG Carinae", Publications of the Astronomical Society of the Pacific, 95: 157–162, Bibcode:1983PASP...95..157C, doi:10.1086/131138.
  • Swings, J. P. (1974), "Similarities in the spectra of three southern peculiar emission line stars with infrared excesses: HD 45677, HD 87643 and GG Carinae (HD 94878)", Astronomy and Astrophysics, 34: 333–334, Bibcode:1974A&A....34..333S.