X Trianguli Australis
X Trianguli Australis is a star in the southern constellation Triangulum Australe. It is a red-hued carbon star with an average apparent magnitude of +5.89. It is approximately 1173 light years (360 parsecs) from Earth,[7] though this could vary by up to 200 light years.[8] It is a semi-regular variable star with two periods of around 385 and 455 days, and is of spectral type C5.5(Nb).[9] It ranges from magnitudes 5.03 to 6.05.[10] Its designation is from the variable star designation developed by German astronomer Friedrich Wilhelm Argelander.
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Triangulum Australe |
Right ascension | 15h 14m 19.17448s[1] |
Declination | −70° 04′ 46.1266″[1] |
Apparent magnitude (V) | +5.75[2] |
Characteristics | |
Spectral type | C5.5[3] |
B−V color index | 3.271±0.019[2] |
Variable type | Lb[4] |
Astrometry | |
Radial velocity (Rv) | −3.2±1.5[5] km/s |
Proper motion (μ) | RA: +4.276[1] mas/yr Dec.: −7.566[1] mas/yr |
Parallax (π) | 3.5388 ± 0.1944[1] mas |
Distance | 920 ± 50 ly (280 ± 20 pc) |
Absolute magnitude (MV) | −1.97[2] |
Details | |
Luminosity (bolometric) | 8,599[6] L☉ |
Temperature | 2,860±350[6] K |
Other designations | |
Database references | |
SIMBAD | data |
It is a cool star, with estimates of its surface temperature ranging from 2200 to 2700 Kelvin.[8] A giant star, its diameter is 400 times that of the sun, and if placed at the center of the Solar System would stretch out to 30% further than Mars' orbit. Its absolute magnitude is −2.0.[8]
References
- Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051.
- 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.
- Warner, B. (1963). "Spectral classification of some Southern late-type peculiar stars". Monthly Notices of the Royal Astronomical Society. 126: 61. Bibcode:1963MNRAS.126...61W. doi:10.1093/mnras/126.1.61.
- Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
- Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- Rau, G.; et al. (April 2017). "The adventure of carbon stars. Observations and modeling of a set of C-rich AGB stars". Astronomy & Astrophysics. 600: 21. arXiv:1701.04331. Bibcode:2017A&A...600A..92R. doi:10.1051/0004-6361/201629337. S2CID 49571205. A92.
- "V* X TrA". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 18 January 2013.
- Kaler, Jim (19 October 2012). "X Trianguli Australis". Stars. University of Illinois. Retrieved 18 January 2013.
- Tabur, V.; Bedding, T. R. (2009). "Long-term Photometry and Periods for 261 Nearby Pulsating M Giants". Monthly Notices of the Royal Astronomical Society. 400 (4): 1945–61. arXiv:0908.3228. Bibcode:2009MNRAS.400.1945T. doi:10.1111/j.1365-2966.2009.15588.x. S2CID 15358380.
- "X TrA". International Variable Star Index. American Association of Variable Star Observers. 11 November 2011. Retrieved 18 January 2013.