(cba:news) Nova Aquilae 1999 No. 2 = V1494 Aql
jop at astro.columbia.edu
Sat Jul 1 15:09:40 EDT 2000
I spent a little while studying the reports on this star (Rudolf and
Alon), and several nights' data from Lew Cook. Everything they said
looks right to me: periodic humps every 90 min or so, amplitude 0.05 mag
or so. Quite an amazing spectacle in a nova still 8 magnitudes
above minimum light.
There's really just one precedent for such behavior: V1500 Cyg in 1975
(and ever since). It showed a 3.3 hr variation that turned out to
be close to Porb but not quite. The period is continuing to slowly
evolve towards Porb, and is today most commonly interpreted as the
rotation period of the white dwarf. This could be a second example
- or, it could in some manner be reflecting Porb exactly. A third
possibility, mentioned by Alon, is a superhump. We gotta find out!
V1500 Cyg showed pronounced spectroscopic variations at the same or
very similar period. Cindy Taylor and John Thorstensen are on
spectroscopic observing runs right now, so we should all agree that
their names will live in (CBA) infamy if they don't track this star
spectroscopically. And this star is really ideal for us to track with
our usual time-series photometry: magnitude 10.5
(keep exposures short, careful about saturation) and without
hemispheric bias (RA 19 23 5.38, DEC +04 57 20.1, J2000).
So let's jump to it! I can practically hear the slewing motors of the MDM
telescopes right now, if Cindy and John know what's good for 'em.
By the way this was that quite spectacular naked-eye nova near Altair last
fall - the Universe Semester's only nova!
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