Misplaced Pages

Theta Chamaeleontis, Latinized from θ Cha, is a single, orange-hued star located in the southern constellation of Chamaeleon. It is a dim star but visible to the naked eye with an apparent magnitude of 4.34. Parallax measurements by the Hipparcos spacecraft put the system at 155 light-years, or 47.6 parsecs away. It is moving away from the Sun with a radial velocity of +22 km/s.

Theta Chamaeleontis is an evolved K-type giant star with a stellar classification of K2 IIIb CN0.5, where the suffix notation indicates the outer atmosphere has a mild overabundance of cyanogen. It has 0.94 times the mass of the Sun, and has expanded to 11.5 times as wide. The star is radiating 60 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,570 K.

It has a visual companion, Theta Chamaeleontis B. This is a magnitude 12.44 star at an angular separation of 21.1 arcseconds from component A along a position angle of 237°, as of 2000.

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. ^ Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A.
3. ^ Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373.
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. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
8. Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466–3471. Bibcode:2001AJ....122.3466M. doi:10.1086/323920.

v t e Constellation of Chamaeleon
List of stars in Chamaeleon Chamaeleon in Chinese astronomy
Stars	Bayer α β γ δ δ ε ζ η θ ι κ μ μ ν π Variable R T Z RS RZ CT CU DI DR DX DY HR 3393 3543 3695 4170 4268 4385 4397 4507 4509 4649 4976 5188 HD 63454 (Ceibo) 115088 116852 Other 2MASS J11011926–7732383 AB ChaHα8 CHXR 73 L 34-26 WISEA J120037.79-784508.3
Exoplanets Cha 110913−773444 ChaHα8 b COCONUTS-2b HD 63454 b OTS 44
Star clusters η Chamaeleontis cluster
Nebulae Chamaeleon complex NGC 3195 IC 2631
Galaxies	NGC 2915
Category

• K-type giants
• Chamaeleon
• Bayer objects
• Durchmusterung objects
• Henry Draper Catalogue objects
• Hipparcos objects
• Bright Star Catalogue objects