Photometric Observations and Period Analysis of an SU UMa-type Dwarf Nova, MASTER OT J004527.52+503213.8

Volume 51 number 1 (2023)

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Sena A. Matsui

Division of Particle and Astrophysical Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464–8602, Japan, and Department of Biosphere-Geosphere Science, Okayama University of Science, 1-1 Ridaicho, Kita-ku, Okayama 700–0005, Japan; sena.ma@nagoya-u.jp

Tsutomu T. Takeuchi

Division of Particle and Astrophysical Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464–8602, Japan, and The Research Center for Statistical Machine Learning, the Institute of Statistical Mathematics, 10-3 Midori-cho, Tachikawa, Tokyo 190—8562, Japan; takeuchi.tsutomu.g8@f.mail.nagoya-u.ac.jp

Kai T. Kono

Division of Particle and Astrophysical Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464–8602, Japan; kono.kai@c.mbox.nagoya-u.ac.jp

Suchetha Cooray

Division of Particle and Astrophysical Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464–8602, Japan, and Research Fellow of the Japan Society for the Promotion of Science (DC1); cooray@nagoya-u.jp

Abstract

MASTER OT J004527.52+503213.8 (hereafter MASTER J004527) is a dwarf nova discovered by the MASTER project in 2013. At 18:20 UTC on 24 October 2020, brightening of this object was reported to vsnet-alert (24843 by Denisenko). This was the second report of a superoutburst after its discovery. Photometric observations were made using the 23.5-cm Schmidt-Cassegrain telescope at Okayama University of Science observatory soon after the alert through 4 November 2020. In this work, we present the photometric data from our observation, and the analysis of the light curves of MASTER J004527 during the 2020 outburst. We propose a method to determine the period of superhumps by polynomial fitting, which can be applied to a light curve with many missing data. In addition to our own data, we incorporate other all sky survey data of the outburst to better understand the properties of the superhumps. Based on our observations, we conclude that MASTER J004527 is an SU UMa-type dwarf nova, since no early superhumps occurred.