CX Canis Majoris explained

CX CMa (CX Canis Majoris) is a blue variable star in the Canis Major constellation.^{[1] [2]} Discovery of this variable is usually credited to German Astronomer Cuno Hoffmeister in 1931, although this remains uncertain.^[3]

It is an eclipsing binary of Algol (detached) whose magnitude varies between 9.9 and 10.4 with a period of 0.95462500 day (22.911000 hour). The variability was first discovered in 1931.^[4] Doubts arose because of scatter in the data and the small amplitude,^[5] but the discovery was confirmed by 1949.^[6] Its Algol-type light curve exhibits the O'Connell effect, meaning that there is a magnitude difference between subsequent maxima.^[7]

The temperature of the secondary star has been estimated at 10,600 K and its mass at . The spectral type of the secondary star is estimated to be in the B8 to A0 range.^[8]

Notes and References

1. Web site: CX CMa. SIMBAD Astronomical Database. Strasbourg Astronomical Data Center. 2016-09-01.
2. Web site: VSX: Detail for CX CMa. The International Variable Star Index. American Association of Variable Star Observers. 2016-09-01.
3. 1984BAAS...16..506M. Photometry &Spectroscopy of Southern O'Connell Effect Systems VY Cru, CX CMa, TU Cru, AQ Mon, &DQ Vel. Bulletin of the American Astronomical Society. 16. 506. Milone. E. F.. 1984.
4. 1931AN....242..129H . Hoffmeister, C. . 1931 . 316 neue Veränderliche . Astronomische Nachrichten . 242 . 7 . 131. 10.1002/asna.19312420702 .
5. Florya, N. . Untersuchungen von 77 veränderlichen Sternen in Monoceros, Canis major und Puppis . Trudy Gosudarstvennogo Astronomicheskogo Instituta Im. P.K. Sternberga; T. 8 . 8 . 5 . 1937TrSht...8....5F . 1937 . 2 .
6. 1949PLAGL..12E..17D . Deurinck, R. . 1949 . Fourteen New Variable Stars in Canis Major, Puppis and Monoceros. Publications du Laboratoire d'Astronomie et de Géodésie de l'Université de Louvain . 12 . 1ll . E17.
7. E. F. Milone . 1984 . Photometry and Spectroscopy of Southern O'Connell Effect Systems VY Cru, CX CMa, TU Cru, AQ Mon, and DQ Vel . Bulletin of the American Astronomical Society . 16 . 506 . 1984BAAS...16..506M .
8. Robert H. Nelson, Dirk Terrell . CX CMa - an early type detached eclipsing binary . Information Bulletin on Variable Stars . 5545 . 30 July 2004 . 2004IBVS.5545....1N . 5545. 1 .