Beta Caeli

Beta Caeli (β Caeli) is the Bayer designation for a star in the southern constellation of Caelum. It is a dim star but visible to the naked eye, having an apparent visual magnitude of 5.04.[2] Based upon an annual parallax shift of 4.88 mas as seen from Earth,[1] it is located 94 light years from the Sun. The star is moving away from the Sun with a radial velocity of +28.8 km/s.[4]

Beta Caeli
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Caelum
Right ascension  04h 42m 03.48029s[1]
Declination −37° 08 39.4641[1]
Apparent magnitude (V) 5.04[2]
Characteristics
Spectral type F3 V[3] or F3 IV[4]
U−B color index +0.01[2]
B−V color index +0.38[2]
Astrometry
Radial velocity (Rv)28.8±0.8[4] km/s
Proper motion (μ) RA: +46.59[1] mas/yr
Dec.: +193.56[1] mas/yr
Parallax (π)34.88 ± 0.42[1] mas
Distance94 ± 1 ly
(28.7 ± 0.3 pc)
Absolute magnitude (MV)+2.64[5]
Details
Mass1.32[6] M
Radius1.3[7] R
Surface gravity (log g)4.09[6] cgs
Temperature6,763±230[6] K
Metallicity [Fe/H]−0.12[3] dex
Rotational velocity (v sin i)97.5±4.9[5] km/s
Age1.753[6] Gyr
Other designations
β Cae, CD−37° 1867, FK5 1130, GJ 176.1, HD 29992, HIP 21861, HR 1503, SAO 195239[8]
Database references
SIMBADdata

This is a probable single-lined spectroscopic binary star system.[9] The visible component has a stellar classification of F3 V[3] or F3 IV,[4] indicating it is either an F-type main-sequence star or a somewhat more evolved subgiant star, respectively. It has an estimated 1.3[6] times the mass of the Sun and about 1.3[7] times the Sun's radius. The star is 1.75[6] billion years old and has a high rate of spin with a projected rotational velocity of around 97.5 km/s.[5]

The companion may be a brown dwarf or a low-mass star orbiting more than 3 AU from the primary. This object may be the source of the X-ray emission coming from the same location.[9]

References

  1. 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.
  2. Cousins, A. W. J. (1973), "UBV photometry of some southern stars", Monthly Notes of the Astronomical Society of Southern Africa, 32: 11, Bibcode:1973MNSSA..32...11C.
  3. Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637.
  4. Torres, C. A. O.; et al. (December 2006), "Search for associations containing young stars (SACY). I. Sample and searching method", Astronomy and Astrophysics, 460 (3): 695–708, arXiv:astro-ph/0609258, Bibcode:2006A&A...460..695T, doi:10.1051/0004-6361:20065602.
  5. Ammler-von Eiff, M.; Reiners, A. (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: 31, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, A116.
  6. 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.
  7. Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (Third ed.), 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
  8. "bet Cae". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-09-09.
  9. Borgniet, Simon; et al. (2016), "Extrasolar planets and brown dwarfs around AF-type stars. IX. The HARPS southern sample", Astronomy & Astrophysics, 599: A57, arXiv:1608.08257, Bibcode:2017A&A...599A..57B, doi:10.1051/0004-6361/201628805.
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