Sudden Period Change and Dimming of the Eclipsing Binary V752 Centauri

Volume 43 number 1 (2015)

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Anthony Mallama

14012 Lancaster Lane, Bowie, MD 20715; anthony.mallama@gmail.com

Hristo Pavlov

9 Chad Place, St. Clair, NSW 2759, Australia; hristo_dpavlov@yahoo.com

Abstract

Video photometry was used to determine a time of minimum light of V752 Centauri at heliocentric JD 2457051.1458 ± 0.0002. The observed time was late by nearly two hours relative to the ephemeris in the General Catalouge of Variable Stars (GCVS). Analysis of this and other timings indicates that the orbital period of V752 Cen increased abruptly by 7.49 × 10–6 days in 2004 after remaining constant for at least the previous 34 years. Simultaneously, the star became fainter by 0.07 magnitude in the V band during primary eclipse, as indicated by an analysis of ASAS data. Dimming of 0.02 to 0.03 magnitude occurred at other phases in the light curve, too. By 2008 the star had returned to its normal brightness. The dimming and the period change may both have been the consequence of material escaping from one of the stars. The deepening of the primary eclipse is also consistent with a color change.