Tau Cancri
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer |
| Right ascension | 09h 08m 00.050s[1] |
| Declination | +29° 39′ 15.24″[1] |
| Apparent magnitude (V) | +5.42[2] |
| Characteristics | |
| Evolutionary stage | red clump[3] |
| Spectral type | G8 III[4] |
| U−B color index | +0.57[2] |
| B−V color index | +0.89[2] |
| Astrometry | |
| Radial velocity (Rv) | −13.90±0.14[5] km/s |
| Proper motion (μ) | RA: −32.199 mas/yr[1] Dec.: +2.640 mas/yr[1] |
| Parallax (π) | 12.0346±0.1007 mas[1] |
| Distance | 271 ± 2 ly (83.1 ± 0.7 pc) |
| Absolute magnitude (MV) | +0.81[6] |
| Details[5] | |
| Mass | 2.42±0.09 M☉ |
| Radius | 7.76±0.51 R☉ |
| Luminosity | 40 L☉ |
| Surface gravity (log g) | 3.21 cgs |
| Temperature | 5,153 K |
| Metallicity [Fe/H] | −0.06 dex |
| Rotational velocity (v sin i) | 1.95±0.45 km/s |
| Age | 620±60 Myr |
| Other designations | |
| τ Cnc, 72 Cancri, BD+30°1817, FK5 2719, HD 78235, HIP 44818, HR 3621, SAO 80650[7] | |
| Database references | |
| SIMBAD | data |
Tau Cancri is a solitary,[4] yellow-hued star in the zodiac constellation of Cancer. Its name is a Bayer designation that is Latinized from τ Cancri, and abbreviated Tau Cnc or τ Cnc. With an apparent visual magnitude of +5.42,[2] it is faintly visible to the naked eye. Based upon an annual parallax shift of 12.03 mas as seen from Earth,[1] it is located around 272 light-years (83 pc) from the Earth. The star is drifting closer to the Sun with a line of sight velocity of −14 km/s.[5]
With an age of about 620[5] million years and a stellar classification of G8 III,[4] this is a red-clump giant star,[3] which indicates that it has evolved onto the horizontal branch and is generating energy through helium fusion at its core. It is a microvariable, showing a luminosity variation of 0.04 in magnitude.[8] Tau Cancri has an estimated 2.4 times the mass of the Sun and 7.8 times the Sun's radius. The star radiates 40 times the solar luminosity from its photosphere at an effective temperature of 5,153 K.[5] It is spinning slowly with a projected rotational velocity of 2 km/s.[5]
References
- ^ a b c d e 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.
- ^ a b c d Argue, A. N. (1963), "UBV photometry of 300 G and K type stars", Monthly Notices of the Royal Astronomical Society, 125 (6): 557–570, Bibcode:1963MNRAS.125..557A, doi:10.1093/mnras/125.6.557
- ^ a b Adelman, Saul J. (2001), "On the Photometric Variability of Red Clump Giants", Baltic Astronomy, 10 (4): 593–597, Bibcode:2001BaltA..10..593A, doi:10.1515/astro-2001-0404, S2CID 118317147.
- ^ 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 d e f Jofré, E.; et al. (2015), "Stellar parameters and chemical abundances of 223 evolved stars with and without planets", Astronomy & Astrophysics, 574: A50, arXiv:1410.6422, Bibcode:2015A&A...574A..50J, doi:10.1051/0004-6361/201424474, S2CID 53666931.
- ^ Da Silva, Ronaldo; et al. (2015), "Homogeneous abundance analysis of FGK dwarf, subgiant, and giant stars with and without giant planets", Astronomy & Astrophysics, 580: A24, arXiv:1505.01726, Bibcode:2015A&A...580A..24D, doi:10.1051/0004-6361/201525770, S2CID 119216425.
- ^ "tau Cnc", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2017-06-11.
- ^ Adelman, S. J.; et al. (December 2000), "On the Variability of G0-G9 Stars", Information Bulletin on Variable Stars, 4993: 1, Bibcode:2000IBVS.4993....1A.