[3] At peak brightness, M31-RV was the most luminous red supergiant in the Local Group.

During the outburst, both V838 Mon and M31-RV reached a maximum absolute visual magnitude of -9.8.

[1] In 2006, the area around M31-RV was observed using the Hubble Space Telescope, but only red giants were seen.

[2] M31-RV reached a peak visual magnitude of 17 before fading rapidly and showing dust formation.

The most likely explanation states that these outbursts occur during stellar merger events.