Omega1 Cancri
Omega1 Cancri, which is Latinized from ω1 Cancri, is a yellow-hued star in the zodiac constellation of Cancer. It is a faint star near the lower limit of visibility to the naked eye, having an apparent visual magnitude of 5.85.[2] Based upon an annual parallax shift of 5.2 mas as seen from Earth,[1] this system is roughly 628 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.10 due to interstellar dust.[5] It is receding from the Sun with a radial velocity of +2 km/s.[3]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 00m 55.87305s[1] |
| Declination | +25° 23′ 34.2160″[1] |
| Apparent magnitude (V) | 5.85[2] |
| Characteristics | |
| Spectral type | G8 III[3] |
| U−B color index | +0.88[2] |
| B−V color index | +1.02[2] |
| Astrometry | |
| Radial velocity (Rv) | +1.90[3] km/s |
| Proper motion (μ) | RA: +16.563[1] mas/yr Dec.: +7.102[1] mas/yr |
| Parallax (π) | 5.1955 ± 0.0817[1] mas |
| Distance | 628 ± 10 ly (192 ± 3 pc) |
| Absolute magnitude (MV) | −2.27[4] |
| Details | |
| Mass | 3.41[3] M☉ |
| Radius | 17.91±0.32[1] R☉ |
| Luminosity | 176.5±3.4[1] L☉ |
| Surface gravity (log g) | 2.21±0.57[5] cgs |
| Temperature | 5,070±177[3] K |
| Metallicity [Fe/H] | +0.15±0.19[5] dex |
| Age | 270[3] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
At an estimated age of 270 million years, this is an evolved G-type giant with a stellar classification of G8 III.[3] With the supply of hydrogen at its core exhausted, the star has cooled and expanded to 18 times the girth of the Sun.[1] It has 3.4 times the mass of the Sun and is radiating 224 times the solar luminosity from its photosphere at an effective temperature of 5,070.[3] The surface metallicity of this star – what astronomers term the abundance of elements other than hydrogen and helium – is 41% higher than in the Sun.[5]
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. Gaia DR2 record for this source at VizieR.
- Walker, R. L., Jr. (April 1971), "UBV Photometry of 173 PZT Stars", Publications of the Astronomical Society of the Pacific, 83 (492): 177, Bibcode:1971PASP...83..177W, doi:10.1086/129097.
- Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal, 150 (3), 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88.
- Schiavon, Ricardo P. (July 2007), "Population Synthesis in the Blue. IV. Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations", The Astrophysical Journal Supplement Series, 171 (1): 146–205, arXiv:astro-ph/0611464, Bibcode:2007ApJS..171..146S, doi:10.1086/511753.
- Koleva, M.; Vazdekis, A. (February 2012), "Stellar population models in the UV. I. Characterisation of the New Generation Stellar Library", Astronomy & Astrophysics, 538: 13, arXiv:1111.5449, Bibcode:2012A&A...538A.143K, doi:10.1051/0004-6361/201118065, A143.
- "ome Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-07.
