(cba:news) Time for a change!
jop at astro.columbia.edu
Sat Sep 21 22:45:47 EDT 2002
Thanks so much for your faithful coverage during all my down and recovery
time! We're up to 55 days now on V1432 Aql; with a 48 day supercycle,
we've covered one plus a little extra... so we can finally quit on that
At first LS Peg was looking really intractable. But after enough data
rolled in, it was evident that the star has a pretty simple photometric
variation after all. Your basic negative superhumps, with epsilon =
-0.041+-0.003. It looks pretty constant in phase and amplitude throughout
the 44 day campaign, except for a coupla nights when the star was ~0.4 mag
There's also some QPOs and assorted riffraff... but the star is
sufficiently well specified that we can say sayonara for the year (and
probably for a few years).
Good, that knocks out our two red-letter targets. The third CBA target,
V1494 Aql, is a personal favorite but I have to admit that the light curve
is pretty damn well specified by our June-July data. So let's wipe the
slate clean and go to all new stars.
We have an upcoming observing run at Kitt Peak, and our prime object will
probably be KUV 01584-0939, a 16.6 mag helium CV with an orbital period
near 10.3 minutes. This is borderline too faint for good CBA measures...
but we could use observations from the bigger scopes, and
especially AU/NZ since we have no coverage there explicitly planned.
(Woudt and Warner will observe it from SAAO, so Africa is well covered.)
The ideal evening CBA target for both hemispheres is FO Aqr. Although
we've been getting scattered pulse timings over the years, we've never had
a campaign, and the one we carried out on its kissin' cousin AO Psc
revealed quite surprising superhumps. At 13.7 and with huge 21 minute
pulses, it gives data suitable for framing!
If you're northerly and have a little more glass, try GD 552 (=Cep 1). We
have HST data over the next month, and would like to compare with the
optical behavior. The 105 minute wave is very elusive - so you probably
won't like the light curve at all unless the star does something very
Finally there's BO Cet (0206-02) for a little later in the night. Another
whole-world special. Decent X-rays, and decently bright (14-15). Kind of
an unknown. There's gotta be a period in there somewhere - let's find it!
I think I'm pretty much back to normal. Classes have started, and I
really treasure the routine!
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