Kappa1 Coronae Australis

For other star systems with this Bayer designation see κ Coronae Australis

κ^1 Coronae Australis

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Corona Australis
Right ascension	18^h 33^m 23.0809^s[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
κ^1 CrA, 16 G. Coronae Australis[11], CD−38°12896, CPD−38°7538, GC 25315, HD 170868, HIP 90969, HR 6952, SAO 210293, 210296, WDS J18334-3844B[12]
Database references
SIMBAD	data

Kappa^1 Coronae Australis (Kappa^1 CrA), Latinized from κ^1 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.

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 κ^2 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

1. 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.
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. 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.
12. "kap01 CrA". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved August 1, 2022.
13. 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.
14. 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.
15. 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.

External links

• Server7.wikisky.org