The dwarf nova MN Dra: Periodic processes at various phases of the supercycle |
| |
Authors: | E P Pavlenko I B Voloshina M V Andreev S Yu Shugarov A V Baklanov O I Antonyuk N A Parakhin D A Samsonov V G Metlov |
| |
Institution: | (1) National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, China |
| |
Abstract: | We analyze photometry of the dwarf nova MN Dra carried out using various instruments at four observatories on 18 nights between
May 20 and June 28, 2009. The observations cover a variety of activity states of the system: a superoutburst, three normal
outbursts, and quiescence. Analysis of the system’s light curve during the superoutburst decline reveals positive superhumps
that recur, on average, with a period of 0.105 days and are due to the direct apsidal precession of the accretion disk. These
are observed until the end of the superoutburst, but their period decreases at a rate of −24.5 × 10−5 of the period per period. Both the positive-superhump period and its derivative are in good agreement with estimates made
during previous superoutbursts. At the brightness minimum and in normal outbursts, MN Dra displays brightness variations with
a period of 0.096 days, whose amplitude is much larger during the brightness minimum (0.8
m
–1.5
m
) than during normal outbursts (0.1
m
–0.2
m
). We suggest that these brightness variations could be negative superhumps due to nodal precession of the oblique accretion
disk. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|