Infrared Spectroscopy of V838 Monocerotis in 2015 and 2022

We report medium-resolution 0.85−2.45 μm spectroscopy obtained in 2015 and 2022 and high resolution 2.27−2.39 μm and 4.59−4.77 μm spectroscopy obtained in 2015 of V838 Monocerotis, along with modeling of the 0.85−2.45 μm spectrum. V838 Mon underwent a series of eruptions and extreme brightenings in 2002, which are thought to have occured as a result of a stellar merger. The new spectra and modelling of them reveal a disturbed red giant photosphere that is probably continuing to contract and ejecta that are cooling and continuing to disperse at velocities up to 200 km s−1.