Astronomy:T Carinae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Carina |
| Right ascension | 10h 55m 17.22143s[1] |
| Declination | −60° 31′ 01.1999″[1] |
| Apparent magnitude (V) | 5.93[2] |
| Characteristics | |
| Evolutionary stage | Horizontal branch[3] |
| Spectral type | K0III[4] |
| B−V color index | +1.065±0.007[2] |
| Variable type | Constant[5] |
| Astrometry | |
| Radial velocity (Rv) | −25.5±2.9[2] km/s |
| Proper motion (μ) | RA: −34.858[1] mas/yr Dec.: +85.164[1] mas/yr |
| Parallax (π) | 11.4593 ± 0.0762[1] mas |
| Distance | 285 ± 2 ly (87.3 ± 0.6 pc) |
| Absolute magnitude (MV) | 1.08[2] |
| Details | |
| Radius | 9.25+0.21 −0.86[1] R☉ |
| Luminosity | 38.6±0.3[1] L☉ |
| Temperature | 4,729+237 −52[1] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
T Carinae is a star in the southern constellation of Carina. Although given a variable star designation, it is now thought to be constant;[5] the identifier HD 94776 from the Henry Draper catalogue may be used instead. It has an orange hue and is dimly visible to the naked eye with an apparent visual magnitude of 5.93.[2] The distance to this object is approximately 285 light years based on parallax,[1] and it has an absolute magnitude of 1.08.[2] It is drifting closer to the Sun with a radial velocity of −26 km/s.[2]
This is an aging giant star with a stellar classification of K0III,[4] which indicates it has exhausted the supply of hydrogen at its core and expanded off the main sequence. It is a red clump giant, which means it is on the horizontal branch and is undergoing core helium fusion.[3] At present it has nine times the Sun's radius and is radiating 39 times the luminosity of the Sun from its photosphere at an effective temperature of 4,729 K.[1]
When used as a comparison star for AG Carinae in 1914 by H. E. Wood,[7] this object was announced as a candidate variable star. A year later it was determined by R. Innis that it was AG Carinae that varied and this star is constant. Later, T Carinae became flagged as a low amplitude irregular variable.[8] It is now catalogued as a probable constant star.[5]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Laney, C. D. et al. (January 2012), "A new Large Magellanic Cloud K-band distance from precision measurements of nearby red clump stars", Monthly Notices of the Royal Astronomical Society 419 (2): 1637–1641, doi:10.1111/j.1365-2966.2011.19826.x, Bibcode: 2012MNRAS.419.1637L.
- ↑ 4.0 4.1 Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, 1, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode: 1978mcts.book.....H.
- ↑ 5.0 5.1 5.2 Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
- ↑ "HD 94776". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+94776.
- ↑ Wood, H. E. (June 1914), "Discovery of a variable star in Carina", Monthly Notices of the Royal Astronomical Society 74 (8): 698, doi:10.1093/mnras/74.8.698, Bibcode: 1914MNRAS..74..698W.
- ↑ "Variable Star Notes", Journal of the Royal Astronomical Society of Canada 63: 221, August 1969, Bibcode: 1969JRASC..63..221M.
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