Light Curve Morphology Study of UW CrB -- Evidence for a 5 d Superorbital Period

• Published in: arXiv.org
• Main Authors: Hakala, Pasi, Hjalmarsdotter, Linnea, Hannikainen, Diana C, Muhli, Panu
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 30.11.2008
• Subjects: Deposition; Light curve; Mathematical morphology; Morphology; Phase distribution; Photometry; Physics - Astrophysics of Galaxies; Physics - Cosmology and Nongalactic Astrophysics; Physics - Earth and Planetary Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics; Physics - Solar and Stellar Astrophysics; X ray binaries; X ray stars
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0812.0130

Since its discovery in 1990, UW CrB (also known as MS1603+2600) has remained a peculiar source without firm classification. Our current understanding is that it is an Accretion Disc Corona (ADC) low mass X-ray binary. In this paper we present results from our photometric campaign dedicated to studying the changing morphology of the optical light curves. We find that the optical light curves show remarkable evidence for strongly evolving light curve shapes. In addition we find that these changes show a modulation at a period of \(\sim\) 5 days. We interpret these changes as either due to strong periodic accretion disc warping or other geometrical changes due to disc precession at a period of 5 days. Finally, we have detected 11 new optical bursts, the phase distribution of which supports the idea of a vertically extended asymmetric accretion disc.