Lambda Chamaeleontis

Lambda Chamaeleontis, Latinized from λ Chamaeleontis, is a star located in the constellation Musca. Lambda Chamaeleontis is also known as HR 4617, and HD 105340. This star is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.165.[2] It is located 472 light-years (145 parsecs) from the Sun, based on its parallax,[1] but is drifting closer with a radial velocity of −45 km/s.[5]

Lambda Chamaeleontis
Observation data
Epoch J2000      Equinox J2000
Constellation Musca
Right ascension 12h 07m 49.87515s[1]
Declination −75° 22′ 01.2583″[1]
Apparent magnitude (V) 5.165[2]
Characteristics
Spectral type K2II/III[3]
U−B color index +1.37[4]
B−V color index +1.30[4]
Astrometry
Radial velocity (Rv)−45.30±0.8[5] km/s
Proper motion (μ) RA: −92.465[1] mas/yr
Dec.: +18.898[1] mas/yr
Parallax (π)6.9109 ± 0.0916 mas[1]
Distance472 ± 6 ly
(145 ± 2 pc)
Absolute magnitude (MV)−0.40[6]
Details
Radius30.21+1.30
−4.03[1] R☉
Luminosity286.8+4.7
−13.3[1] L☉
Temperature4322+320
−90[1] K
Other designations
λ Cha, CPD−74°880, FK5 2971, HD 105340, HIP 59151, HR 4617, SAO 256905[7]
Database references
SIMBADdata

This is an aging K-type giant/bright giant with a stellar classification of K2II/III.[3] With the supply of hydrogen at its core exhausted, the star expanded and cooled. It now has 30[1] times the radius of the Sun and is radiating 287[1] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,322 K.[1]

The star was first designated Lambda Chamaeleontis by French astronomer Lacaille, in his Coelum Australe Stelliferum. He listed it close to Pi Chamaeleontis in both brightness and location. The IAU redefinition of the constellation borders in 1930, has placed Lambda Chamaeleontis slightly over the border in Musca, rather than Chamaeleon.[8]

References
  1. 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. Gaia DR2 record for this source at VizieR.
  2. Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
  3. Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Vol. 1. Bibcode:1975mcts.book.....H.
  4. Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99. Bibcode:1966CoLPL...4...99J.
  5. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 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.
  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. "HD 105340". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-27.{{cite web}}: CS1 maint: postscript (link)
  8. "Musca Constellation". Constellation Guide; Constellations: A Guide to the Night Sky. Retrieved 25 January 2018.

Further reading
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