Astronomy:Lambda Chamaeleontis

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Short description: Star in the constellation Musca
λ Chamaeleontis
Location of λ Chamaeleontis (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Musca[1]
Right ascension  12h 07m 49.87572s[2]
Declination −75° 22′ 01.2650″[2]
Apparent magnitude (V) 5.165[3]
Characteristics
Evolutionary stage red giant branch[2]
Spectral type K2II/III[4]
U−B color index +1.37[5]
B−V color index +1.30[5]
Astrometry
Radial velocity (Rv)−45.30±0.8[6] km/s
Proper motion (μ) RA: −92.609[2] mas/yr
Dec.: +19.332[2] mas/yr
Parallax (π)6.6166 ± 0.0819[2] mas
Distance493 ± 6 ly
(151 ± 2 pc)
Absolute magnitude (MV)−0.40[1]
Details
Mass1.6[7] M
Radius28[8] R
Luminosity295[8] L
Surface gravity (log g)1.92[7] cgs
Temperature4,544[8] K
Metallicity [Fe/H]−0.26[7] dex
Other designations
λ Cha, CPD−74°880, FK5 2971, HD 105340, HIP 59151, HR 4617, SAO 256905[9]
Database references
SIMBADdata

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. It is located 493 light-years (151 parsecs) from the Sun, based on its parallax, but is drifting closer with a radial velocity of −45 km/s.

This is an aging K-type giant/bright giant with a stellar classification of K2II/III.[4] With the supply of hydrogen at its core exhausted, the star expanded and cooled. It now has 28 times the radius of the Sun[7] and is radiating 295 times the Sun's luminosity[7] from its enlarged photosphere at an effective temperature of 4,544 K.[8]

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.[10]

References

  1. 1.0 1.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A  XHIP record for this object at VizieR.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. Høg, E. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode2000A&A...355L..27H. 
  4. 4.0 4.1 Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars. 1. Bibcode1975mcts.book.....H. 
  5. 5.0 5.1 Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory 4: 99. Bibcode1966CoLPL...4...99J. 
  6. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode2006AstL...32..759G. 
  7. 7.0 7.1 7.2 7.3 7.4 Khalatyan, A.; Anders, F.; Chiappini, C.; Queiroz, A. B. A.; Nepal, S.; Dal Ponte, M.; Jordi, C.; Guiglion, G. et al. (2024). "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost". Astronomy and Astrophysics 691: A98. doi:10.1051/0004-6361/202451427. Bibcode2024A&A...691A..98K. 
  8. 8.0 8.1 8.2 8.3 Fetherolf, Tara; Pepper, Joshua; Simpson, Emilie; Kane, Stephen R.; Močnik, Teo; English, John Edward; Antoci, Victoria; Huber, Daniel et al. (2023). "Variability Catalog of Stars Observed during the TESS Prime Mission". The Astrophysical Journal Supplement Series 268 (1): 4. doi:10.3847/1538-4365/acdee5. Bibcode2023ApJS..268....4F. 
  9. "HD 105340". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+105340. 
  10. "Musca Constellation". Constellation Guide; Constellations: A Guide to the Night Sky. http://www.constellation-guide.com/constellation-list/musca-constellation/. 

Further reading