The classical novae are semi-detached interacting binary systems containing a Roche-lobe filling secondary, on or near the main sequence transferring material via Roche lobe overflow to a companion star (the primary). The mass transfer results in the formation of accretion disk around the primary (white dwarf). The runway thermonuclear reactions on the white dwarf surface give rise to the thermonuclear outburst, the sudden brightening seen in these systems. The results obtained from optical and near-IR observations will be presented. The system parameters of the observed novae, like the distance to the nova, absolute magnitude, expansion velocity as well as geometry of the ejecta and mass are estimated. The dust formation and the detection of first overtone emission bands of CO in these novae will be discussed.
Speaker : Dr. Ashish Raj
Post-Doctoral Fellow, Indian Institute of Astrophysics, II Block Koramangala, Bangalore