Optical photometry of GM Cep: evidence for UXor type of variability

Abstract

Results from optical photometric observations of the pre-main sequence star GM Cep are reported in the paper. The star is located in the field of the young open cluster Trumpler 37 - a region of active star formation. GM Cep shows a large amplitude rapid variability interpreted as a possible outburst from EXor type in previous studies. Our data from BVRI CCD photometric observations of the star are collected from June 2008 to February 2011 in Rozhen observatory (Bulgaria) and Skinakas observatory (Crete, Greece). A sequence of sixteen comparison stars in the field of GM Cep was calibrated in the BVRI bands. Our photometric data for a 2.5 years period show a high amplitude variations (Delta V ~ 2.3m) and two deep minimums in brightness are observed. The analysis of collected multicolor photometric data shows the typical of UX Ori variables a color reversal during the minimums in brightness. On the other hand, high amplitude rapid variations in brightness typical for the Classical T Tauri stars also present on the light curve of GM Cep. Comparing our results with results published in the literature, we conclude that changes in brightness are caused by superposition of both: (1) magnetically channeled accretion from the circumstellar disk, and (2) occultation from circumstellar clouds of dust or from features of a circumstellar disk.

7 pages, 3 figures, accepted for publication in Ap&SS

References in corpus (3)

• Variable accretion as a mechanism for brightness variations in T Tau S
• The Rapid Outbursting Star GM Cep: An EX-or in Tr 37?
• Long-Term Light Curve of Highly-Variable Protostellar Star GM Cep

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• A Possible Detection of Occultation by a Proto-planetary Clump in GM Cephei
• Diagnosing the Clumpy Protoplanetary Disk of the UXor Type Young Star GM Cephei
• A new insight into the V1184 Tau variability
• Long-term Photometric Study of the Pre-main Sequence Star V1180 Cas
• Study of the long-term $BV{R}_c{I}_c$ photometric variability of eight PMS stars in the young open cluster Trumpler 37
• Simultaneous photometric and spectral analysis of a new outburst of V1686 Cyg