(cba:news) V1084 Her, no; V503 Cyg, V1432 Aql si; plus the DQ Hers
jop at astro.columbia.edu
Thu May 31 17:11:08 EDT 2012
A few notes before starting my trip home.
I've studied the V1084 Her data (mostly Tom). Flickers like crazy, but
the periodic signal was invisible despite the very good quality of the
data. Time to quit.
Let's start the season on V503 Cyg and V1432 Aql. For the latter, an
asynchronous polar, we're trying to measure the changing period of the
photometric wave that signifies rotation. That will yield the timescale
for synchronization - thought to be a few hundred years, but not
decisively specified by observation. It takes pretty long seasonal
coverage to completely rule out cycle-count ambiguities - so let's
start! You probably need 3-hour time series, but there's no great
advantage in going longer.
The same type of program is appropriate for V503 Cyg, but of course the
motivation is vastly different. It's a borderline ER UMa star, and
likely to erupt in the next 2 weeks. We especially favor time series in
superoutburst (positive superhump guaranteed) and quiescence (negative
superhump very likely). The fast up-and-down stuff the ER UMas
sometimes throw at you - usually in the range 15-16 - is of lower
priority; it can be hard to extract periodic signals during these
phases. In fact, it would be very good to keep a close eye on the THREE
borderline ER UMa guys: V503 Cyg, SS UMi, and IX Dra - and send any
detection of (super)outburst or deep quiescence to cba-chat.
And it's the season for DQ Hers. Everyone observing these should become
familiar with Koji Mukai's intermediate polar web-page. It lists all
the stars, with lots of useful info. Pick out a nice star for your
latitude and time of night, make sure it's optically bright enough (they
mostly are, but check to be sure), and get a 2-3 hour light curve.
Unlike our usual programs, there's no great advantage in concentrating
on one star for many successive nights. Spread the wealth - the purpose
here is to establish a long-term O-C, so steady light pressure on these
stars is just fine. BTW add one important one to the list: RXJ1654-19.
And I hope australites will nail EX Hya for a final end-of-season
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