Omicron Leonis
Omicron Leonis is located to the lower far right on this map of the constellation. | |
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Leo |
Right ascension | 09h 41m 09.03s |
Declination | +09° 53' 32.30" |
Apparent magnitude (V) | +3.52[1] |
Characteristics | |
Spectral type | F8-G0III + A7m[2] |
U−B color index | 0.21[1] |
B−V color index | 0.49[1] |
Astrometry | |
Proper motion (μ) | RA: -143.20[3] mas/yr Dec.: -37.20[3] mas/yr |
Parallax (π) | 25.03[3] ± 0.22 mas |
Distance | 135 ly (41.4±0.1[4] pc) |
Absolute magnitude (MV) | +0.51[5] |
Orbit[4] | |
Period (P) | 14.498064 ± 0.000009 days |
Semi-major axis (a) | 4.46 ± 0.01 mas |
Eccentricity (e) | 0 |
Inclination (i) | 57.6 ± 0.1° |
Longitude of the node (Ω) | 191.4 ± 0.1° |
Periastron epoch (T) | TJD 10629.831 ± 0.003 |
Details[4] | |
ο Leo A | |
Mass | 2.12 M☉ |
Radius | ±0.5 5.9 R☉ |
Luminosity | ±2.4 39.4 L☉ |
Temperature | ±200 6,000 K |
Age | 800(estimate) Myr |
ο Leo B | |
Mass | ±0.01 1.87 M☉ |
Radius | ±0.3 2.2 R☉ |
Luminosity | ±1.0 15.4 L☉ |
Temperature | ±400 7,600 K |
Other designations | |
Database references | |
SIMBAD | data |
Omicron Leonis (ο Leonis, abbreviated Omicron Leo, ο Leo) is a multiple star system in the constellation of Leo, west of Regulus, some 130 light-years from the Sun, where it marks one of the lion's forepaws.
It consists of a binary pair, designated Omicron Leonis A and an optical companion, Omicron Leonis B.[6] 'A's' two components are themselves designated Omicron Leonis Aa (also named Subra[7]) and Ab.
Nomenclature
ο Leonis (Latinised to Omicron Leonis) is the star's Bayer designation. The designations of the two constituents as Omicron Leonis A and B, and those of A's components - Omicron Leonis Aa and Ab - derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).[8]
It bore the traditional name Subra.[9] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[10] to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[11] It approved the name Subra for the component Omicron Leonis Aa on 12 September 2016 and it is now so included in the List of IAU-approved Star Names.[7]
Properties
The primary is given the type F8-G0III giant and the secondary is a type A7m dwarf.[4] Their combined apparent magnitude is +3.52.
References
- 1 2 3 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
- ↑ Ginestet, N.; Carquillat, J. M. (2002). "Spectral Classification of the Hot Components of a Large Sample of Stars with Composite Spectra, and Implication for the Absolute Magnitudes of the Cool Supergiant Components". The Astrophysical Journal Supplement Series. 143 (2): 513. Bibcode:2002ApJS..143..513G. doi:10.1086/342942.
- 1 2 3 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357.
- 1 2 3 4 Hummel, C. A.; Carquillat, J. -M.; Ginestet, N.; Griffin, R. F.; Boden, A. F.; Hajian, A. R.; Mozurkewich, D.; Nordgren, T. E. (2001). "Orbital and Stellar Parameters of Omicron Leonis from Spectroscopy and Interferometry". The Astronomical Journal. 121 (3): 1623. Bibcode:2001AJ....121.1623H. doi:10.1086/319391.
- ↑ 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.
- ↑ "Washington Double Star Catalog". United States Naval Observatory. Retrieved 2 January 2018.
- 1 2 "Naming Stars". IAU.org. Retrieved 16 December 2017.
- ↑ Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
- ↑ Jim Kaler's website: http://stars.astro.illinois.edu/sow/subra.html (online 6th Sep 2015)
- ↑ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016.
- ↑ "WG Triennial Report (2015-2018) - Star Names" (PDF). p. 5. Retrieved 2018-07-14.
External links
- Omicron Leo/Subra in Kaler Stars
- Subra (HIP 47508) Relates to the A star, Subra-B
- Subra - Omi Leonis brief data.