(cba:news) TY Vul and V1084 Her (RX1643+34)
jop at astro.columbia.edu
Tue Jun 22 16:10:12 EDT 2010
Richard Sabo just sent me a night of data on TY Vul - clear, strong
superhumps at a period about 2 hours. First time ever! Fire at will.
Lots of northern dwarf novae peppering the predawn summer sky. Best to
pick one and stick with it, usually. I'll try to keep everyone posted
on the ups and downs of each.
Speaking of which... two other stars I failed to report on a few days
ago. A few of you (led by Bill Goff) have tackled our hardest target
star, sdss 1339+48. Bill's observations do show the pulsations, which I
wondered about. But they, along with the big-telescope data which
preceded it, also show that the pulsations are not stable over baselines
greater than a few days. In fact, I suspect that this is true of all
the GW Lib stars. It means that long campaigns don't reap uniquely
valuable rewards - revealing tiny rates of period change, for example.
So let's put sdss1339 aside.
And for the same reason... let's resurrect V1084 Her = RX1643+34. I've
now analyzed all 2010 data on this bright novalike - and was somewhat
amazed to find the negative superhump at *exactly* the same frequency as
in 2001. Generally one doesn't expect disk precession to show a good
clock; none of the others do. So now this object is (somewhat) uniquely
curious, and it's bright enough to be a good target for maybe 2 more
months. Good northern evening target, or all night if you'd like a
bright target. Try to use star #2 of Mickaelian et al. 2002 as your
V1084 Her is near V795 Her in brightness, coordinates, and reason to
observe. You'll probably want to pick one or the other... but the more
sure winner right now is V1084.
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