wmartin@brl-tgr.ARPA (Will Martin ) (10/07/85)
There are a lot of popularized books around these days on cosmology, the Big Bang, black holes, etc. One practically invariant feature of these books is that they describe the process by which a star of given mass evolves, and how it will end up as a red dwarf if it is small enough, a white dwarf if it is of a certain size range, and a supernova and black hole if it is large enough. There seems to be no mention anymore, though, of "ordinary" novae -- just supernovae. What is the current astronomical thought regarding the cause(s) of a star going nova? (NOT supernova, just nova.) Will Martin UUCP/USENET: seismo!brl-bmd!wmartin or ARPA/MILNET: wmartin@almsa-1.ARPA
ethan@utastro.UUCP (Ethan Vishniac) (10/08/85)
> > What is the current astronomical thought regarding the cause(s) of a > star going nova? (NOT supernova, just nova.) > > Will Martin Since I'm a cosmologist, I'd probably be on firmer ground answering any other question you might have, but what the hell. Current thought on novae is that they arise from mass transfer in binary systems. Best guess is that one object is degenerate and accretes gas from its companion, which it periodically blows off with a bang by igniting the hydrogen. -- "Superior firepower is an Ethan Vishniac important asset when {charm,ut-sally,ut-ngp,noao}!utastro!ethan entering into ethan@astro.UTEXAS.EDU negotiations" Department of Astronomy University of Texas
freeman@spar.UUCP (Jay Freeman) (10/09/85)
[] In article <1950@brl-tgr.ARPA> wmartin@brl-tgr.ARPA (Will Martin ) writes: >What is the current astronomical thought regarding the cause(s) of a >star going nova? (NOT supernova, just nova.) One thought: Suppose you have a binary in which one component is much more compact than a main-sequence star -- a white dwarf would do. Suppose that (via any of several mechanisms) "ordinary" stellar material -- mostly hydrogen -- accretes onto the compact component. As the layer of hydrogen on its surface gets thicker and thicker, the bottom gets hotter and hotter, until -- BOOM -- thermonuclear fusion occurs and a lot of the hydrogen burns quite suddenly. (Details buried in physics.) -- Jay Reynolds Freeman (Schlumberger Palo Alto Research)(canonical disclaimer)