Kappa1 Coronae Australis
Kappa1 Coronae Australis (Kappa1 CrA), Latinized from κ1 Coronae Australis, is a star located in the southern constellation Corona Australis. It has an apparent magnitude of 6.17, placing it near the limit for naked eye visibility.
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Corona Australis |
| Right ascension | 18h 33m 23.0809s[1] |
| Declination | −38° 43′ 12.166″[1] |
| Apparent magnitude (V) | 6.17±0.01[2] |
| Characteristics | |
| Spectral type | A0 IV[3] |
| B−V color index | −0.06[4] |
| Astrometry | |
| Radial velocity (Rv) | −16±3.7[5] km/s |
| Proper motion (μ) | RA: −0.512 mas/yr[1] Dec.: −22.550 mas/yr[1] |
| Parallax (π) | 4.4833 ± 0.0831 mas[1] |
| Distance | 730 ± 10 ly (223 ± 4 pc) |
| Absolute magnitude (MV) | −0.78 |
| Details[6] | |
| Mass | 2.82±0.38 M☉ |
| Radius | 3.79±0.15 R☉ |
| Luminosity | 179±14 L☉ |
| Surface gravity (log g) | 3.73±0.07 cgs |
| Temperature | 11,079[7] K |
| Metallicity [Fe/H] | −0.2[8] dex |
| Rotational velocity (v sin i) | 339[9] km/s |
| Age | 4.1±1.8[10] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
There has been some disagreement about the object's distance. The New Hipparcos Reduction calculates a parallax of 21.18±6.53 mas,[13] yielding a distance of 154±47 light years, somewhat poorly constrained. New analysis from the Gaia spacecraft find that it has a physical relation to κ2 Coronae Australis.[14] Both of their currently parallaxes place them around 700 light years away.[1] As of 2018, the two stars have an angular separation of 20.5″ along a position angle of 359°.[15]
Kappa1 CrA has a stellar classification of A0 IV,[3] indicating that it is a slightly evolved A-type star. At present it has 2.8 times the mass of the Sun and a slightly enlarged radius of 3.79 R☉.[6] It radiates at 179 times the luminosity of the Sun[6] from its photosphere at an effective temperature of 11,079 K.[7] Kappa1 CrA's metallicity – specifically the iron abundance – is 63% that of the Sun.[8] With an age of about four million years, Kappa1 CrA is modelled to be a young star only about 10% of the way through its main sequence life.[9]
References
- Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361.
- Pickles, A.; Depagne, É. (December 2010). "All-Sky Spectrally MatchedUBVRI - ZY and u′g′r′i′z′ Magnitudes for Stars in the Tycho2 Catalog". Publications of the Astronomical Society of the Pacific. 122 (898): 1437–1464. arXiv:1011.2020. Bibcode:2010PASP..122.1437P. doi:10.1086/657947. eISSN 1538-3873. ISSN 0004-6280.
- Corben, P. M. (1971). "Photoelectric Magnitudes and Colours for Bright Southern Stars". Monthly Notes of the Astronomical Society of South Africa. 30: 37. Bibcode:1971MNSSA..30...37C. ISSN 0024-8266.
- Kharchenko, N.V.; Scholz, R.-D.; Piskunov, A.E.; Röser, S.; Schilbach, E. (November 2007). "Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ~55000 stars and mean radial velocities of 516 Galactic open clusters and associations". Astronomische Nachrichten. 328 (9): 889–896. arXiv:0705.0878. Bibcode:2007AN....328..889K. doi:10.1002/asna.200710776. ISSN 0004-6337.
- Stassun, Keivan G.; et al. (9 September 2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal. 158 (4): 138. arXiv:1905.10694. Bibcode:2019AJ....158..138S. doi:10.3847/1538-3881/ab3467. ISSN 0004-6256.
- McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (21 November 2012). "Fundamental parameters and infrared excesses of Hipparcos stars: Parameters and IR excesses from Hipparcos". Monthly Notices of the Royal Astronomical Society. 427 (1): 343–357. arXiv:1208.2037. Bibcode:2012MNRAS.427..343M. doi:10.1111/j.1365-2966.2012.21873.x. ISSN 0035-8711.
- Anders, F.; et al. (February 2022). "Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia EDR3 stars brighter than G = 18.5". Astronomy & Astrophysics. 658: A91. arXiv:2111.01860. Bibcode:2022A&A...658A..91A. doi:10.1051/0004-6361/202142369. eISSN 1432-0746. ISSN 0004-6361.
- Zorec, J.; Royer, F. (January 2012). "Rotational velocities of A-type stars IV: Evolution of rotational velocities". Astronomy & Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. eISSN 1432-0746. ISSN 0004-6361. S2CID 55586789.
- Tetzlaff, N.; et al. (January 2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. S2CID 118629873.
- Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
- "kap01 CrA". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved August 1, 2022.
- van Leeuwen, F. (13 August 2007). "Validation of the new Hipparcos reduction". Astronomy & Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. eISSN 1432-0746. ISSN 0004-6361.
- Makarov, Valeri V. (2020). "Two-epoch Orbit Estimation for Wide Binaries Resolved in Hipparcos and Gaia". The Astronomical Journal. 160 (6): 284. arXiv:2010.03628. Bibcode:2020AJ....160..284M. doi:10.3847/1538-3881/abbe1c. S2CID 222209002.
- Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (December 2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. ISSN 0004-6256.