Astron. Astrophys. 364, 694-700 (2000)

Activity of DX Andromedae - the dwarf nova with a very long recurrence time of outbursts ^*

V. imon

Academy of Sciences, Astronomical Institute, 251 65 Ondejov, Czech Republic (simon@asu.cas.cz)

Received 9 August 2000 / Accepted 9 October 2000

Abstract

An analysis of the historical light curve of the dwarf nova DX And, spanning over 18 years, is presented. The typical recurrence time of the outbursts 270-330 days is one of the longest among CVs above the period gap. The diagram for displays both smaller cycle-to-cycle variations and large occasional changes. The maximum brightness of the respective outbursts is variable by . There is a correlation between the maximum brightness of outburst and the length of the preceding cycle but no correlation with the length of the following cycle. While the slope of the rising branches of the outbursts is largely dependent on the maximum brightness (brighter outbursts having steeper rise) the decay branches remain very similar for most outbursts. The activity is discussed in the framework of the thermal instability model and implications of the different values of for the lengths of the respective cycles and the shapes of the outburst light curves are presented.

Key words: stars: activity stars: binaries: close stars: binaries: general stars: circumstellar matter stars: novae, cataclysmic variables stars: individual: DX And

* This research has made use of the AFOEV database, operated at CDS (France), and VSNET database (Japan).

Send offprint requests to: simon@asu.cas.cz

SIMBAD Objects

Contents

• 1. Introduction
• 2. Sources of the data
• 3. Analysis of the data
  • 3.1. General description
  • 3.2. The outburst cycle-length and its variations
  • 3.3. Relation between the maximum brightness and
  • 3.4. Morphology of the outburst light curves
• 4. Discussion
• Acknowledgements
• References

© European Southern Observatory (ESO) 2000

Online publication: January 29, 2001
helpdesk.link@springer.de