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A Photometric Study of the Misclassified Variable AK Ursae Minoris

Volume 43 number 2 (2015)

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Horace A. Dale III
Emory University Department of Physics, 400 Dowman Drive, Atlanta, GA 30322; hdale@emory.edu
Lauren A. Sgro
Emory University Department of Physics, 400 Dowman Drive, Atlanta, GA 30322; hdale@emory.edu

Abstract

The star AK UMi [GSC 4656-0461] was originally misidentified as an RRc-Lyrae pulsating variable by analyzing undersampled survey data. We used greater time resolved differential photometry to positively identify this variable as a W UMa overcontact (subtype A) binary system. The secondary minimum is a total eclipse, which enabled us to approximate the model for this system using some well-known characteristics of overcontact binaries. Our model solution parameters were found to be: i = 90˚, q = 0.21 (M2/M1), and T1 = 6750K, which indicated that the primary should be an F4.