Detection of Change in Supercycles in ER Ursae Majoris
Abstract
We examined data on about 20 years of observations of ER UMa available in AAVSO, VSNET, AFOEV, NSVS, VSOLJ databases together with published light curves. The obtained O-C diagram revealed a systematic change of the supercycle (time interval between two successive superotbursts) within 43.6 and 59.2 d. The time-scale of this change variation is from 300 to 1900 d. The number of normal outbursts within the supercycles also varied from 4 to 6 although no strong correlation between this number and supercycle length was found. We suggest that appearance of negative superhumps is responsible for the observed variations of number of normal outbursts. Our results generally confirms the expectations by the thermal-tidal instability theory.
Keywords
Cite
@article{arxiv.1212.5940,
title = {Detection of Change in Supercycles in ER Ursae Majoris},
author = {Polina Zemko and Taichi Kato and Sergey Shugarov},
journal= {arXiv preprint arXiv:1212.5940},
year = {2015}
}
Comments
10 pages, 6 figures, accepted for publication in PASJ