Results of a campaign to observe outbursts of the dwarf nova CSS 121005:212625+201948

TL;DR

This study monitored the dwarf nova CSS 121005 over two seasons, revealing its short supercycle, typical outburst behavior, and detailed superhump characteristics, contributing valuable observational data to the understanding of SU UMa-type dwarf novae.

Contribution

It provides the first detailed observational analysis of CSS 121005's superoutbursts, superhumps, and supercycle duration, highlighting its unique short supercycle among SU UMa stars.

Findings

Supercycle length of 66.9 days.

Superoutburst lasted 14 days with >4.8 mag amplitude.

Superhump period of 0.08838 days.

Abstract

A monitoring programme of CSS 121005:212625+201948 covering nearly two observing seasons has shown that it is a typical SU UMa dwarf nova, but it has one of the shortest supercycles of its class, at 66.9(6) d. The superoutbursts are interspersed with 3 to 7 short duration (~2 days) normal outbursts each of which are separated by a mean interval of 11 days, but can be as short as 2 days. The most intensively studied superoutburst was that of 2014 November, which lasted 14 days and had an outburst amplitude of >4.8 magnitudes, reaching magnitude 15.7 at its brightest. Time resolved photometry revealed superhumps with a peak-to-peak amplitude of 0.2 magnitudes, later declining to 0.1 magnitude. The superhump period was Psh = 0.08838(18) d. Time resolved photometry was conducted during several other superoutbursts, which gave broadly similar results.