14 Ceti
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cetus |
| Right ascension | 00h 35m 32.833s[1] |
| Declination | −00° 30′ 20.20″[1] |
| Apparent magnitude (V) | 5.84[2] |
| Characteristics | |
| Evolutionary stage | Hertzsprung gap[3] |
| Spectral type | F5 V[4][5] or F5 IV[2] |
| B−V color index | 0.444±0.006[6] |
| Astrometry | |
| Radial velocity (Rv) | 11.3±0.2[7] km/s |
| Proper motion (μ) | RA: 143.173 mas/yr[1] Dec.: −62.295 mas/yr[1] |
| Parallax (π) | 17.4181 ± 0.0314 mas[1] |
| Distance | 187.3 ± 0.3 ly (57.4 ± 0.1 pc) |
| Absolute magnitude (MV) | 2.26±0.04[8] |
| Details | |
| Mass | 1.55±0.1[2] M☉ |
| Radius | 2.6[2] R☉ |
| Luminosity | 10.7[2] L☉ |
| Surface gravity (log g) | 3.87±0.15[9] cgs |
| Temperature | 6,583±90[9] K |
| Metallicity [Fe/H] | −0.11±0.06[9] dex |
| Rotational velocity (v sin i) | 5[2] km/s |
| Age | 2.1±0.4[9] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
14 Ceti is a single[11] star in the equatorial constellation of Cetus. It is faintly visible to the naked eye under good viewing conditions, having an apparent visual magnitude of 5.84.[2] The distance to 14 Ceti can be estimated from its annual parallax shift of 17.4″,[1] which puts it 187 light years away. It is moving further from the Earth with a heliocentric radial velocity of 11 km/s,[7] having recently come no closer than 178 ly.[6]
Gray (1989) as well as Houk and Swift (1999) have this star classified as an F-type main-sequence star with a stellar classification of F5 V.[4][5] However, in the 5th revised edition of the Bright Star Catalogue it was classed by Hoffleit and Warren (1991) as a more evolved subgiant star with a class of F5 IV.[12] The absolute magnitude and effective temperature for this star shows that it is entering the Hertzsprung gap, which is occupied by a class of stars that have consumed the hydrogen at their core but have not yet begun hydrogen fusion along a shell surrounding the center.[11]
Evolutionary models for this star give an estimated age of around 2.1[9] billion years with 1.6[2] times the mass of the Sun. It has 2.6[2] times the Sun's radius and is radiating 10.7[2] times the Sun's luminosity from its photosphere at an effective temperature of about 6,583 K.[9] There is a thin convective envelope near its surface.[2] The star has a lower abundance of elements more massive than helium – what astronomers' term the metallicity – compared to the Sun.[9] The projected rotational velocity is a relatively low 5 km/s, but the rotation rate is unknown since the axial tilt hasn't been determined.[2]
14 Ceti shows an X-ray emission of 0.33×1030 erg s−1, which is on the high side for an F5 star. Both the corona and chromosphere of this star show indications of a magnetic field, and a surface field was detected in 2009 with a strength of −30 G. This made it the only known star between classes F0 and F7 to have a Zeeman effect detected. Two possible explanations for this field are that it is a fast rotator with a dynamo-driven field, or that it is a former Ap star.[11] The activity properties of this star make it more likely to be the latter.[3]
References
[edit]- ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
- ^ a b c d e f g h i j k l Aurière, M.; et al. (February 2015), "The magnetic fields at the surface of active single G-K giants", Astronomy & Astrophysics, 574: 30, arXiv:1411.6230, Bibcode:2015A&A...574A..90A, doi:10.1051/0004-6361/201424579, S2CID 118504829, A90.
- ^ a b Aurière, M.; et al. (November 2014), "Descendants of magnetic and non-magnetic A-type stars", in Mathys, G.; Griffin, E.; Kochukhov, O.; Monier, R.; Wahlgren, G. (eds.), Putting A Stars into Context: Evolution, Environment, and Related Stars, Proceedings of the international conference held on June 3-7, 2013 at Moscow M.V. Lomonosov State University in Moscow, Russia, Moscow: Pero, pp. 444–450, arXiv:1310.6942, Bibcode:2014psce.conf..444A.
- ^ a b Gray, R. O. (1989), "The extension of the MK spectral classification system to the intermediate population II F type stars", Astronomical Journal, 98 (3): 1049–1062, Bibcode:1989AJ.....98.1049G, doi:10.1086/115195.
- ^ a b Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Ann Arbor, Michigan: Department of Astronomy, University of Michigan, Bibcode:1999MSS...C05....0H.
- ^ a b 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 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065, S2CID 119231169.
- ^ Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191, S2CID 118577511.
- ^ a b c d e f g Bensby, T.; et al. (2014), "Exploring the Milky Way stellar disk. A detailed elemental abundance study of 714 F and G dwarf stars in the solar neighbourhood", Astronomy & Astrophysics, 562 (A71): 28, arXiv:1309.2631, Bibcode:2014A&A...562A..71B, doi:10.1051/0004-6361/201322631, S2CID 118786105.
- ^ "14 Cet". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved December 20, 2018.
- ^ a b c Aurière, M.; et al. (July 2012), "14 Ceti: a probable Ap-star-descendant entering the Hertzsprung gap", Astronomy & Astrophysics, 543: 6, arXiv:1205.6962, Bibcode:2012A&A...543A.118A, doi:10.1051/0004-6361/201219324, S2CID 118482901, A118.
- ^ Hoffleit, D.; Warren, W. H. Jr. (November 1995), "Bright Star Catalogue", VizieR Online Data Catalog (5th Revised ed.), Bibcode:1995yCat.5050....0H.
