Abstract
The observational studies of the old novae have shown that they are close binaries with one of the components a white dwarf accreting hydrogen-rich material from the other component. To determine if the nova outburst could be caused by a thermal runaway in the envelope of the white dwarf, a computer code designed to take short time steps has been used to compute evolutionary sequences for helium-rich white dwarfs with hydrogen-rich envelopes. None of those computed using initial conditions derived from the observations of DQ Her had significant thermal runaways or produced the 10 45 erg observed in the outburst of DQ Her. An evolutionary sequence was then computed which used initial conditions that included the effects of an accretion shock (Starrfield 1970). A thermal runaway resulted which produced the energy observed in the outburst of DQ Her. Two evolutionary sequences were computed with a mass of |$0.5\,{M}_{\odot}$| . A thermal runaway occurred in each sequence and produced more than 10 45 erg. In these models as the peak of the runaway was reached, the shell source compressed and heated the outer layers of the helium core until helium burning was initiated.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.