Low-mass X-ray binary star in the constellation Corona Borealis
UW Coronae Borealis
Observation data Epoch J2000.0 Equinox J2000.0 (ICRS)
Constellation
Corona Borealis
Right ascension
16h 05m 45.873s[1]
Declination
+36° 48′ 35.2″[1]
Apparent magnitude (V)
19.7[2]
Other designations
1E 1603.6+2600, 2E 1603.6+2600, 1RXS J160545.3+255131, SDSS J160545.87+255145.1
Six representative white-light light curves for UW Coronae Borealis, adapted from Hakala et al. (2009)[3]
UW Coronae Borealis, also known as MS 1603.6+2600, is a low-mass X-ray binary star system in the constellation Corona Borealis.[1] Astronomer Simon Morris and colleagues discovered the X-ray source in 1990 and were able to match it up with a faint star with an average visual magnitude of 19.4.[4] The system is thought to be made up of a neutron star that has an accretion disk that draws material from its companion, a star less massive than the Sun. The disk is asymmetrical. The variability of the system is complex, with several periods identified: the two components orbit each other every 111 minutes, while there is another period of 112.6 minutes. The beat period of these is 5.5 days, which is thought to represent the precession of the asymmetrical accretion disk around the neutron star.[5]
^Liu, Q. Z. (2007). "A catalogue of low-mass X-ray binaries in the Galaxy, LMC, and SMC (Fourth edition)". Astronomy and Astrophysics. 469 (2): 807–810. arXiv:0707.0544. Bibcode:2007A&A...469..807L. doi:10.1051/0004-6361:20077303. S2CID 14673570. Retrieved 7 December 2016.
^Hakala, Pasi; Hjalmarsdotter, Linnea; Hannikainen, Diana C.; Muhli, Panu (April 2009). "Light curve morphology study of UW CrB – evidence for a 5 d superorbital period". Monthly Notices of the Royal Astronomical Society. 394 (2): 892–899. arXiv:0812.0130. Bibcode:2009MNRAS.394..892H. doi:10.1111/j.1365-2966.2008.14374.x.
^Morris, Simon L.; Liebert, James; Stocke, John T.; Gioia, Isabella M.; Schild, Rudy E.; Wolter, Anna (1990). "MS 1603.6 + 2600, an unusual X-ray selected binary system at high Galactic latitude". Astrophysical Journal. 365 (20): 686–95. Bibcode:1990ApJ...365..686M. doi:10.1086/169523.
^Mason, Paul A.; Robinson, Edward L.; Bayless, Amanda J.; Hakala, Pasi J. (2012). "Long-term Optical Observations of Two LMXBS: UW CrB (=MS 1603+260) and V1408 Aql (=4U 1957+115)". The Astronomical Journal. 144 (4): 108. Bibcode:2012AJ....144..108M. doi:10.1088/0004-6256/144/4/108. hdl:2152/34339. S2CID 122184568.