(cba:news) some beautiful data... ('Joe Patterson' via CBA News) [2026-08-25T21:47:01Z]

on QR And rolling off the computer these days.  We haven't talked much 
about old  QR recently - mostly because we haven't talked much at all 
recently!  But you know, it's a close relative of T Pyx and IM Nor - 
which get more attention because they're obviously ERUPTIVE stars.  But 
QR And is *permanently* of very high luminosity.  It seems to be a 
SUPERSOFT binary - very, very blue and probably near 10**37 erg/s.

Most of the good papers written about supersofts are ~25 years old.  On 
that timescale, people move on to other subjects, even when many 
unsolved problem are still lying around.  At around V~11, QR And is 
really well-suited for CBA coverage (on good nights, of course).  I'll 
write again soon and recommend which papers to consult.  And, with a 
period near 10 hours, it's basically a star for two-continent study... 
so I'll send you the quality data from the USA and Europe.

Also some recommendations about supersofts.  These guys are powered by 
accretion, of course, but a certain fraction of the accreted matter 
(maybe all) is promptly burned in NUCLEAR reactions, which release ~40x 
more energy than accretion (depending on masses etc.)

The period is ~13 hours (I;m too lazy to look it up), but it's 
double-humped, so it can be a little tricky to tell if you're seeing a 
primary or secondary minimum.  V Sagittae is another star like this - in 
practically all respects.  That too is a very good (and bright) target 
for Sep-Oct observing... and also requires long runs since its Porb is 
12.5 hours.

joe

--
You received this message because you are subscribed to the Google Groups "CBA News" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cbastro-news+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion visit https://groups.google.com/d/msgid/cbastro-news/5a31bf4c-73fa-4350-becd-e08571c4bf17%40astro.columbia.edu.