A nova is a star that suddenly increases its light by orders of magnitudes and then fades away to its former luminosity in a few months. The phenomenon is due to a violent explosion which ejects stellar material into the interstellar medium. V745 in the constellation of Scorpius is a binary system composed by a red giant and a white dwarf. Its latest nova outburst has been observed on 2014 February 6. The model shows the outcome about 17 days after the explosion. An equatorial density enhancement around the binary system is shown in blue; the material ejected during the outburst and the associated blast wave are marked in yellow-orange. The red giant is visible at the center of the scene; the white dwarf (where the explosion occurs) is visible as a bright spot slightly displaced from the red giant.
Reference: Orlando et al. 2017, MNRAS 464, 5003.
Credits: INAF - Osservatorio Astronomico di Palermo. The Milky Way image is from ESO/S. Brunier.