Lambda Coronae Australis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Corona Australis |
| Right ascension | 18h 43m 46.94143s[1] |
| Declination | −38° 19′ 24.3941″[1] |
| Apparent magnitude (V) | 5.11[2] + 10.01[3] |
| Characteristics | |
| Spectral type | A0/1V[4] + K0[5] |
| B−V color index | +0.075±0.002[6] |
| Astrometry | |
| Radial velocity (Rv) | −26.40±4.2[7] km/s |
| Proper motion (μ) | RA: +1.047[1] mas/yr Dec.: −53.774[1] mas/yr |
| Parallax (π) | 15.8771 ± 0.2823 mas[1] |
| Distance | 205 ± 4 ly (63 ± 1 pc) |
| Absolute magnitude (MV) | 1.15[2] |
| Details | |
| λ CrA A | |
| Mass | 2.17±0.10[2] M☉ |
| Radius | 2.24[2] R☉ |
| Luminosity | 31.25[6] L☉ |
| Surface gravity (log g) | 4.08±0.08[2] cgs |
| Temperature | 8,609[8] K |
| Metallicity [Fe/H] | −0.30[8] dex |
| Rotational velocity (v sin i) | 148.6±1.6[9] km/s |
| Age | 273[10] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
λ Coronae Australis, Latinized as Lambda Coronae Australis is a binary star[5] system located in the southern constellation of Corona Australis. It is visible to the naked eye as a faint, white-hued point of light with an apparent visual magnitude of 5.11.[2] The system is located at a distance of 205 light-years, based on parallax,[1] and is drifting further away with a radial velocity of −26 km/s.[7]
The primary member of this system, designated component A, is an A-type main-sequence star with a stellar classification of A0/1V.[4] It is 273[10] million years old and is spinning with a projected rotational velocity of 149 km/s.[9] This high rotation rate is producing an equatorial bulge that is 7% larger than the polar radius.[12] It has 2.17 times the mass of the Sun and 2.24 times the Sun's radius.[2] The star is radiating 31[6] times the Sun's luminosity from its photosphere at an effective temperature of 8,609 K.[8]
The secondary companion, component B,[13] has an apparent visual magnitude of 10.01[3] and a class of K0.[5] As of 2016, it has an angular separation of 29.5″ from the primary along a position angle of 213°.[3] Component C[14] is a visual companion of magnitude 9.9 and separation 43.3″ from the primary.[3]
References
[edit]- ^ a b c d e f 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. Gaia DR2 record for this source at VizieR.
- ^ a b c d e f g Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A.
- ^ a b c d Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920, retrieved 2015-07-22
- ^ a b Houk, N.; Smith-Moore, M. (1988). Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Vol. 4. Ann Arbor, MI: Department of Astronomy, University of Michigan. Bibcode:1988mcts.book.....H.
- ^ a b c Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. S2CID 14878976.
- ^ 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.
- ^ a b Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 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.
- ^ a b c Erspamer, D.; North, P. (2003). "Automated spectroscopic abundances of a and F-type stars using echelle spectrographs. II. Abundances of 140 A-F stars from ELODIE". Astronomy and Astrophysics. 398 (3): 1121–1136. arXiv:astro-ph/0210065. Bibcode:2003A&A...398.1121E. doi:10.1051/0004-6361:20021711. S2CID 1109164.
- ^ a b Díaz, C. G.; et al. (July 2011). "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum". Astronomy & Astrophysics. 531: A143. arXiv:1012.4858. Bibcode:2011A&A...531A.143D. doi:10.1051/0004-6361/201016386. S2CID 119286673.
- ^ a b David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. S2CID 33401607.
- ^ "lam CrA". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-16.
- ^ van Belle, Gerard T. (March 2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review. 20 (1): 51. arXiv:1204.2572. Bibcode:2012A&ARv..20...51V. doi:10.1007/s00159-012-0051-2. S2CID 119273474.
- ^ "CD-38 13036B". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-16.
- ^ "CD-38 13036C". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-16.
