AN EXTREMELY MASSIVE WHITE DWARF OF THE SYMBIOTIC CLASSICAL NOVA V407 CYG AS SUGGESTED BY THE RS OPH AND U SCO MODELS

作者：Hachisu I^*; Kato M

来源：Baltic Astronomy, 2012, 21(1-2): 68-75.

DOI：10.1515/astro-2017-0360

• binaries: symbiotic
• novae, cataclysmic variables
• stars: individual (RS Oph, U Sco, V407 Cyg)
• white dwarfs

We have analyzed the optical light curve of the symbiotic star V407 Cyg that underwent a classical nova outburst in 2010 March. Being guided by a supersoft X-ray phase observed during days 20-40 after the nova outburst, we are able to reproduce the light curve during a very early phase of the nova outburst. Our model consists of an outbursting white dwarf and an extended equatorial disk. An extremely massive white dwarf of 1.35-1.37 M-circle dot is suggested. The optical light curve is also consistent with a sharp drop 47 days after the outburst, which is the end of hydrogen shell-burning on the white dwarf. Although the extremely massive white dwarf is favourable to the interpretation that V407 Cyg is a recurrent nova, enrichment of heavy elements in the ejecta suggests that the white dwarf is eroded and, as a result, its mass is not increasing. Therefore, V407 Cyg may not explode as a Type Ia supernova even if it is a carbon-oxygen white dwarf.

• 出版日期2012