The Infrared Evolution of Dust in V838 Monocerotis

TL;DR

This study uses infrared observations from SOFIA and Spitzer to track the evolving dust composition around V838 Mon, providing insights into dust formation processes in stellar mergers.

Contribution

It presents the first detailed temporal analysis of dust evolution in V838 Mon using combined infrared spectra from SOFIA and Spitzer.

Findings

Detection of alumina and silicate dust formation sequences.

Evidence of classical dust condensation in an oxygen-rich environment.

Real-time observation of dust composition changes over 20 years.

Abstract

Luminous Red Variables (LRVs) are most likely eruptions that are the outcome of stellar mergers. V838 Mon is one of the best-studied members of this class, representing an archetype for stellar mergers resulting from B-type stars. As result of the merger event, nova-like eruptions occur driving mass-loss from the system. As the gas cools considerable circumstellar dust is formed. V838 Mon erupted in 2002 and is undergoing very dynamic changes in its dust composition, geometry, and infrared luminosity providing a real-time laboratory to validate mineralogical condensation sequences in stellar mergers and evolutionary scenarios. We discuss recent NASA Stratospheric Observatory for Infrared Astronomy SOFIA 5 to 38 micron observations combined with archival NASA Spitzer spectra that document the temporal evolution of the freshly formed (within the last 20 yrs) circumstellar material in the environs of V838 Mon. Changes in the 10 micron spectral region are strong evidence that we are witnessing a classical dust condensation sequence expected to occur in oxygen-rich environments where alumina formation is followed by that of silicates at the temperature cools.