T Ceti
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cetus |
| Right ascension | 00h 21m 46.27529s[2] |
| Declination | −20° 03′ 28.9098″[2] |
| Apparent magnitude (V) | 5.61[3] (5.0 - 6.9)[4] |
| Characteristics | |
| Spectral type | M5-6Se[5] |
| B−V color index | 1.58±0.03[3] |
| Variable type | SRc[6] |
| Astrometry | |
| Radial velocity (Rv) | +28.9±0.9[7] km/s |
| Proper motion (μ) | RA: +59.665[2] mas/yr Dec.: −10.229[2] mas/yr |
| Parallax (π) | 3.70 ± 0.47 mas[8] |
| Distance | approx. 900 ly (approx. 270 pc) |
| Absolute magnitude (MV) | −1.51[3] |
| Details[6] | |
| Mass | 3.0±0.3 M☉ |
| Radius | 275±34 R☉ |
| Luminosity | 8,128+2,587 −1,962 L☉ |
| Surface gravity (log g) | 0.01±0.11 cgs |
| Temperature | 3,396+103 −100 K |
| Metallicity [Fe/H] | 0.0 dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
T Ceti is a semiregular variable star located in the equatorial constellation of Cetus. It varies between magnitudes 5.0 and 6.9 over 159.3 days.[4] The stellar parallax shift measured by Hipparcos is 3.7 mas,[8] which yields a distance estimate of roughly 900 light years. It is moving further from the Earth with a heliocentric radial velocity of +29 km/s.[7]
This is an MS-type star on the asymptotic giant branch with a spectral type of M5-6Se.[5] (The 'e' notation indicates the presence of emission lines in the spectrum). The star is losing mass at the rate of 8.2×10−8 M☉ y−1,[10] and it is surrounded by a circumstellar dust shell consisting of crystallized, mostly iron-rich silicates.[11]
T Ceti has an estimated three times the mass of the Sun and has expanded to 275 times the Sun's radius. It is radiating 8,128 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,396 K.[6]
References
[edit]- ^ "ASAS All Star Catalogue". The All Sky Automated Survey. Retrieved 8 December 2021.
- ^ a b c d 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.
- ^ a b c 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. S2CID 119257644.
- ^ a b Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
- ^ a b Keenan, Philip C (1954). "Classification of the S-Type Stars". The Astrophysical Journal. 120: 484. Bibcode:1954ApJ...120..484K. doi:10.1086/145937.
- ^ a b c Cruzalebes, P.; et al. (2013). "Fundamental parameters of 16 late-type stars derived from their angular diameter measured with VLTI/AMBER". Monthly Notices of the Royal Astronomical Society. 434 (1): 437–450. arXiv:1306.3288. Bibcode:2013MNRAS.434..437C. doi:10.1093/mnras/stt1037. S2CID 49573767.
- ^ a b de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
- ^ a b 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. S2CID 18759600.
- ^ "T Cet". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 28 August 2018.
- ^ Wallerstein, G.; et al. (November 2011), "Carbon isotopic abundance ratios in S-type stars", Astronomy & Astrophysics, 535: 7, Bibcode:2011A&A...535A.101W, doi:10.1051/0004-6361/201015280, A101
- ^ Guha Niyogi, Suklima; et al. (June 2011), "A Temporal Study of the Oxygen-rich Pulsating Variable Asymptotic Giant Branch Star, T Cep: Investigation on Dust Formation and Dust Properties", The Astrophysical Journal, 733 (2): 15, arXiv:1103.5040, Bibcode:2011ApJ...733...93G, doi:10.1088/0004-637X/733/2/93, S2CID 118332811, 93
