Discovery of Two New Eruptions of the Ultrashort Recurrence Time Nova M31N 2017-01e

TL;DR

This paper reports the discovery of two new eruptions of the recurrent nova M31N 2017-01e, updates its recurrence time, and characterizes its quiescent counterpart, providing insights into its eruption cycle and stellar environment.

Contribution

It presents the first detection of two eruptions of M31N 2017-01e, refines its recurrence period, and offers spectral and photometric analysis of its quiescent state, advancing understanding of ultrashort recurrence novae.

Findings

Recurrence time of 924 days for M31N 2017-01e.

Discovery of two new eruptions in 2014 and 2024.

Identification of the quiescent counterpart as an evolved B star.

Abstract

We report the recent discovery of two new eruptions of the recurrent nova M31N 2017-01e in the Andromeda galaxy. The latest eruption, M31N 2024-08c, reached $R=17.8$ on 2024 August 06.85 UT, $\sim2$ months earlier than predicted. In addition to this recent eruption, a search of archival PTF data has revealed a previously unreported eruption on 2014 June 18.46 UT that reached a peak brightness of $R\sim17.9$ approximately a day later. The addition of these two eruption timings has allowed us to update the mean recurrence time of the nova. We find $\langle T_\mathrm{rec} \rangle = 924.0\pm7.0$ days ($2.53\pm0.02$ yr), which is slightly shorter than our previous determination. Thus, M31N 2017-01e remains the nova with the second shortest recurrence time known, with only M31N 2008-12a being shorter. We also present a low-resolution spectrum of the likely quiescent counterpart of the nova, a $\sim20.5$ mag evolved B star displaying an $\sim14.3$ d photometric modulation.