Delta1 Chamaeleontis

Delta1 Chamaeleontis, Latinized from δ1 Chamaeleontis, is a close double star located in the constellation Chamaeleon. It has a combined apparent visual magnitude of 5.47,[2] which is just bright enough for the star to be faintly seen on a dark rural night. With an annual parallax shift of 9.36 mas,[1] it is located around 350 light years from the Sun. This pair is one of two stars named Delta Chamaeleontis, the other being the slightly brighter Delta2 Chamaeleontis located about 6 arcminutes away.[9] Delta Chamaeleontis forms the southernmost component of the constellation's "dipper" or bowl. Together with Gamma Chamaeleontis, they point to a spot that is within 2° of the south celestial pole.[10]

For other stars with this Bayer designation, see δ Chamaeleontis.
δ1 Chamaeleontis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Chamaeleon
Right ascension 10h 45m 16.31446s[1]
Declination −80° 28′ 10.5409″[1]
Apparent magnitude (V) 5.47[2] (6.266 + 6.503)[3]
Characteristics
Spectral type K0 III[4]
U−B color index +0.74[2]
B−V color index +0.95[2]
Astrometry
Radial velocity (Rv)+10.7[5] km/s
Proper motion (μ) RA: −17.28[1] mas/yr
Dec.: −29.25[1] mas/yr
Parallax (π)9.36 ± 0.45[1] mas
Distance350 ± 20 ly
(107 ± 5 pc)
Absolute magnitude (MV)+0.32[6]
Details
Luminosity76[7] L☉
Temperature5,052[7] K
Other designations
δ1 Cha, CPD−79° 554, HD 93779, HIP 52595, HR 4231, SAO 258592.[8]
Database references
SIMBADdata

The two components of Delta1 Chamaeleontis have visual magnitudes of 6.3 and 6.5. As of 2000, the pair had an angular separation of 0.783 arcseconds along a position angle of 83.8°.[3] They can be separated by a 7.9 in (20 cm) aperture telescope.[9] The pair is a source of X-ray emission with a flux of 27.4×10−17 W/m2.[11] The stellar classification of Delta1 Chamaeleontis is K0 III,[4] which matches an evolved K-type giant star.

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, S2CID 18759600.
  2. Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
  3. 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.
  4. Houk, N.; Cowley, A. P. (1975), Catalogue of two-dimensional spectral types for the HD stars, I, University of Michigan, Bibcode:1975mcts.book.....H.
  5. Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington, D.C., Bibcode:1953GCRV..C......0W.
  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, S2CID 119257644.
  7. McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
  8. "del01 Cha -- Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-12-11.
  9. Inglis, Michael (2012), Astronomy of the Milky Way: The Observer's Guide to the Southern Milky Way, The Patrick Moore Practical Astronomy Series, Springer Science & Business Media, p. 106, ISBN 978-1447106418.
  10. O'Meara, Stephen James (2002), Deep-Sky Companions: The Caldwell Objects, Cambridge University Press, p. 424, ISBN 0521827965.
  11. Hunsch, M.; et al. (January 1998), "The ROSAT all-sky survey catalogue of optically bright late-type giants and supergiants", Astronomy and Astrophysics Supplement, 127 (2): 251–255, Bibcode:1998A&AS..127..251H, doi:10.1051/aas:1998347.
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