# V729 Sgr: A long period dwarf nova showing negative superhumps during quiescence

## TL;DR

This study presents K2 observations of V729 Sgr, revealing unique long and short outburst patterns, and the detection of negative superhumps during quiescence in a long-period cataclysmic variable.

## Contribution

First detection of negative superhumps during quiescence in a long-period CV, with detailed outburst characterization from K2 data.

## Key findings

- Five short and two long outbursts observed
- Negative superhumps detected during quiescence
- Outburst intervals are unprecedented for CVs above the period gap

## Abstract

We report K2 observations of the eclipsing cataclysmic variable V729 Sgr which covered nearly 80 days in duration. We find five short outbursts and two long outbursts, one of which shows a clear plateau phase in the rise to maximum brightness. The mean time between successive short outbursts is ~10 d while the time between the two long outbursts is ~38 d. The frequency of these outbursts are unprecedented for a CV above the orbital period gap. We find evidence that the mid-point of the eclipse occurs systematically earlier in outburst than in quiescence. During five of the six quiescent epochs we find evidence for a second photometric period which is roughly 5 percent shorter than the 4.16 h orbital period which we attribute to negative superhumps. V729 Sgr is therefore one of the longest period CVs to show negative superhumps during quiescence.