AAVSO: American Association of Variable Star Observers

A Photometric Study of the Near-Contact Binary XZ Persei

Volume 45 number 1 (2017)

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Edward J. Michaels
Stephen F. Austin State University, Department of Physics, Engineering and Astronomy, P.O. Box 13044, Nacogdoches, TX 75962; emichaels@sfasu.edu


Presented are two sets of multi-band CCD photometry of the Algol-type binary XZ Persei. Photometric solutions were derived using the Wilson-Devinney program for each dataset. The solution results indicate XZ Per is a semi-detached, near-contact binary whose less-massive secondary star fills its Roche lobe. Asymmetries in the light curves were modeled by including a hot spot on the primary star. This spot is likely caused by impact heating from mass transfer. The orbital period was analyzed using 473 light minima spanning 90 years. Several alternating period changes were found superimposed on a long term secular period decrease. With continued mass and angular momentum loss, the separation between the stars will likely decrease until the primary fills its Roche lobe forming a contact binary.