Swift X-ray and UV Observations of SDSS J141118.31+481257.6 During its First Ever Recorded Superoutburst

TL;DR

This study presents the first detailed X-ray and UV observations of SDSS J141118.31+481257.6 during its inaugural superoutburst, revealing unprecedented UV brightness changes and insights into its outburst behavior.

Contribution

It provides the first recorded X-ray and UV data of the system during superoutburst, highlighting the largest UV amplitude observed in an AM CVn system and analyzing outburst timing and brightness changes.

Findings

Detected three outbursts with ~7 mag UV amplitude

Largest UV outburst amplitudes for an AM CVn system

X-ray emission not correlated with UV brightness changes

Abstract

SDSS J141118.31+481257.6 is an ultracompact white dwarf binary (or AM CVn system) with an orbital period of 46 min. We analyze ~23 ks of X-ray and UV data taken with the Neil Gehrels Swift Observatory during its first ever recorded outbursts. The events took place 13 years after the system was discovered. We detected 3 events in our UV data, all with amplitudes of ~7 mags with respect to quiescence, the largests detected for an AM CVn system so far. The first 2 events correspond to a superoutburst and the third one to another detected outburst. The 3 episodes that we identified occurred in a period of 24 days, each one displaying very rapid brightness changes. At ~120 days since the detection of the superoutburst, the system remains 1 magnitude brighter in UV compared to the quiescence level. The X-ray observations suggest that the X-ray emission is not correlated with the UV.