X Caeli, or Gamma2 Caeli, is a binary star system in the southern constellation of Caelum. It is barely visible to the naked eye with an apparent visual magnitude of 6.32.[5] based upon an annual parallax shift of 9.6 mas,[1] it is located 341 light-years from Earth. The system is moving further away with a heliocentric radial velocity of +6 km/s.[7]
 The constellation Caelum near the horizon, with the four main stars marked by a line | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Caelum |
| Right ascension | 05h 04m 26.19316s[1] |
| Declination | −35° 42′ 17.7574″[1] |
| Apparent magnitude (V) | 6.28 – 6.39[2] (6.43 + 9.65)[3] |
| Characteristics | |
| Spectral type | F2 IV/V[4] |
| B−V color index | 0.311±0.006[5] |
| Variable type | δ Sct[6] |
| Astrometry | |
| Radial velocity (Rv) | +6.4±0.8[7] km/s |
| Proper motion (μ) | RA: +28.39[8] mas/yr Dec.: +41.71[8] mas/yr |
| Parallax (π) | 9.5567 ± 0.0583 mas[1] |
| Distance | 341 ± 2 ly (104.6 ± 0.6 pc) |
| Absolute magnitude (MV) | 1.36[5] |
| Details | |
| Mass | 1.52[9] M☉ |
| Radius | 3.43±0.32[10] R☉ |
| Luminosity | 23.65[5] L☉ |
| Surface gravity (log g) | 3.80[9] cgs |
| Temperature | 7,227±246[9] K |
| Rotational velocity (v sin i) | 69.0±1.0[10] km/s |
| Age | 961[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
The yellow-white-hued primary, component A, has an apparent magnitude of +6.32 and stellar classification of F2 IV/V,[4] showing mixed traits of an F-type main-sequence star and a subgiant. It is classified as a Delta Scuti-type variable star and its brightness varies from magnitude +6.28 to +6.39 with a period of 3.25 hours. A 2000 observing campaign identified at least six independent pulsation modes for this variation.[10] The companion star, component B, has an apparent magnitude of +9.65 and, as of 2000, is at an angular separation of 0.890″ along a position angle of 183°.[3]
References
edit- ^ 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.
- ^ VSX:Detail for X Cae, retrieved 2018-08-24.
- ^ a b Fabricius, C.; Makarov, V. V. (April 2000), "Two-colour photometry for 9473 components of close Hipparcos double and multiple stars", Astronomy and Astrophysics, 356: 141–145, Bibcode:2000A&A...356..141F.
- ^ a b Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
- ^ a b c d 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.
- ^ 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): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
- ^ 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.
- ^ a b van Leeuwen, F. (November 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.
- ^ a b c d David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ a b c Mantegazza, L.; et al. (February 2000), "Simultaneous intensive photometry and high resolution spectroscopy of delta Scuti stars. IV. An improved picture of the pulsational behaviour of X Caeli", Astronomy and Astrophysics, 354: 112–124, arXiv:astro-ph/9911337, Bibcode:2000A&A...354..112M.
- ^ "HD 32846". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 24 August 2018.
- ^ Mantegazza, L.; Poretti, E. (August 1996), "Simultaneous intensive photometry and high resolution spectroscopy of δ Scuti stars. II. X Caeli: a star with unusual spectral features", Astronomy & Astrophysics, 312: 855–864, Bibcode:1996A&A...312..855M.