X-ray and optical study of the new SMC X-ray binary pulsar system SXP7.92 and its probable optical counterpart, AzV285

TL;DR

This paper reports on the discovery and analysis of a new X-ray binary pulsar system in the Small Magellanic Cloud, combining X-ray and optical data to identify its properties and probable optical counterpart.

Contribution

It provides the first detailed X-ray and optical characterization of the SXP7.92 system and identifies its likely optical counterpart AzV285 with a binary period.

Findings

Detected a 7.9s X-ray pulsation period.

Identified a 36.8-day optical binary period.

Discovered a new transient X-ray source in the SMC.

Abstract

Optical and X-ray observations are presented here of a newly reported X-ray transient system in the Small Magellanic Cloud - SXP7.92. A detailed analysis of the X-ray data reveal a coherent period of 7.9s. A search through earlier X-ray observations of the SMC reveal a previously unknown earlier detection of this system. Follow-up X-ray observations identified a new transient source within the error circle of the previous observations. An optical counterpart, AzV285, is proposed which reveals clear evidence for a 36.8d binary period.