X Caeli

X Caeli
Observation data
Epoch J2000      Equinox ICRS
Constellation Caelum
Right ascension 05h 04m 26.157s
Declination −35° 42′ 18.38″
Apparent magnitude (V) 6.28 – 6.39 (6.43 + 9.65)
Characteristics
Spectral type F2 IV/V
B−V color index 0.311±0.006
Variable type δ Sct
Astrometry
Radial velocity (Rv)+6.4±0.8 km/s
Proper motion (μ) RA: +28.361 mas/yr
Dec.: +40.338 mas/yr
Parallax (π)9.7026±0.0221 mas
Distance336.2 ± 0.8 ly
(103.1 ± 0.2 pc)
Absolute magnitude (MV)1.36
Details
X Cae A
Mass1.52 M☉
Radius3.43±0.32 R☉
Luminosity23.65 L☉
Surface gravity (log g)3.80 cgs
Temperature7,227±246 K
Rotational velocity (v sin i)69.0±1.0 km/s
Age961 Myr
Other designations
γ2 Cae, γ2 Caeli, X Caeli, CD−35°2090, GC 6214, HD 32846, HIP 23596, HR 1653, SAO 195534, CCDM 05044-3542, WDS J05044-3542AB
Database references
SIMBADdata

X Caeli is a binary star system in the southern constellation of Caelum. It has the Bayer designation Gamma2 Caeli, which is Latinized from γ2 Caeli and abbreviated Gamma2 Cae or γ2 Cae; X Caeli is the system's variable star designation. This system is barely visible to the naked eye with a combined apparent visual magnitude of 6.32. Based upon an annual parallax shift of 9.7 mas, it is located at a distance of 336 light-years (103 pc) from Earth. The system is moving further away from the Sun with a radial velocity of +6 km/s.

Properties

A visual-band light curve for X Caeli, adapted from Mantegazza and Poretti (1996)

The yellow-white-hued primary, component A, has an apparent magnitude of +6.32 and stellar classification of F2 IV/V, showing mixed traits of an F-type main-sequence star and a subgiant. The spectral lines display a narrow absorption core that suggests the presence of a circumstellar shell.

This star is classified as a Delta Scuti variable with a brightness varies from magnitude 6.28 to 6.39 over a period of 3.25 hours. A 2000 observing campaign identified at least six independent pulsation modes for this variation. It has 1.5 times the mass of the Sun and 3.4 times the Sun's radius. This star is radiating 24 times the luminosity of the Sun from its photosphere at an effective temperature of 7,227 K. It is nearly a billion years old, with a relatively high rate of rotation, showing a projected rotational velocity of 69 km/s.

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°. The orbital period for this binary star system is unknown.

References

  1. 1 2 3 4 5 6 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. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 6 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.
  3. ↑ VSX:Detail for X Cae, retrieved 2018-08-24.
  4. 1 2 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.
  5. 1 2 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.
  6. ↑ Samus', N. N; et al. (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.
  7. 1 2 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.
  8. 1 2 3 4 5 6 7 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.
  9. 1 2 3 4 5 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.
  10. ↑ "HD 32846", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 24 August 2018.
  11. 1 2 Liakos, Alexios; Niarchos, Panagiotis (February 2017), "Catalogue and properties of δ Scuti stars in binaries", Monthly Notices of the Royal Astronomical Society, 465 (1): 1181–1200, arXiv:1611.00200, Bibcode:2017MNRAS.465.1181L, doi:10.1093/mnras/stw2756.
  12. 1 2 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.
  13. ↑ Mantegazza, L.; Poretti, E. (February 1992), "Pulsational behaviour of the delta Scuti star X Caeli", Astronomy and Astrophysics, 255: 153–157, Bibcode:1992A&A...255..153M.