A model of an expanding giant that swallowed planets for the eruption of V838 Monocerotis

Abstract

In early 2002 V838 Monocerotis had an extraordinary outburst, the nature of which is still unclear. The optical light curve showed at least three peaks, and imaging revealed a light echo around the object - evidence for a dust shell which was emitted several thousand years ago and now reflecting light from the eruption. Spectral analysis suggests that the object was relatively cold throughout the event, which was characterized by an expansion to extremely large radii. We show that the three peaks in the light curve have a similar shape and thus it seems likely that a certain phenomenon was three times repeated. Our suggestion that the outburst was caused by the expansion of a red giant, followed by the successive swallowing of three relatively massive planets in close orbits, supplies a simple explanation to all observed peculiarities of this intriguing object.