stars for october

From: Joe Patterson <*jop_at_astro.columbia.edu*> Date: Tue, 12 Oct 2004 09:44:01 -0400 (EDT) · jop_at_astro.columbia.edu

Dear CBAers,

Time for news of campaigns.

The biggest one now is ASAS0025+12.  This one is tapering off now, mostly
because of the recent bright moon and the fact that southerners (on whom
we rely for our Asia-Pacific hole) are not too thrilled by the dec.
Anyway, the star itself is cooperating well, except that it is getting a
bit faint - disappeared from some of your radar screens, though staying on
others.  Still keeping the faith are Anthony Kroes, Lew Cook, Tom Krajci,
Donn Starkey, Dave Messier, Berto Monard, Arto Oksanen. I believe it's
about 16.0 now, and this is getting interestingly close to quiescence.
>From the time series, it seems that the superhumps have persisted,
although they may now be convolved with some other signals at nearby
frequency (orbital humps?)

This is atill a VERY GOOD TARGET, if you can handle the brightness.  You
don't, by the way, need very long exposures to work this star.  Some of
you have been using integration times as long as 5 min. It's true that
such an integration is more "accurate", but these data are for a time
series, and your data will be somewhat more useful if they possess a
little more time resolution.  I'd suggest something more like 90 s (for a
fairly faint star like this) - unless you have a very long readout time.
Most of the modern cameras can read out fast for stellar photometry.

Of course, these are just general remarks, and your analysis of your
own data at the telescope (or later offline) basically trumps these
remarks.

LD317 is a brighter target and also remains interesting, with strong
candidate periods at 3.7 hrs and 35 minutes.

And the third interesting star near Andromeda this season is HS2331+3905.
Pretty faint, but has a whole bushel of periods to keep you happy if
you're blessed with big aperture.

Finally, some of you might want to start up on FY Per, a very bright CV
that has mystified us for years.  Good morning star.  If you do it, EITHER
use a filter (V or R), or confine your observations to airmasses less than
2.0.  Here we're looking for small wiggles on a relatively long period
(1.5 hours), so differential extinction effects can be deadly.  Good
target for the next couple of full moons.

AND IN THE SOUTH, I recommend these.

1. To drop V4140 Sgr (you all did long ago), V1223 Sgr, and EF Tuc.  We
have enough.

2. To consider asas0025+12, if your telescope does not automatically
reject positive declinations.

3. To launch a major campaign on AO Psc.  Northerners to follow suit soon.

4. To start up a campaign on CM Phe, which it is high time we did.

I'm moving to Massachusetts for about 8 months in about an hour - but
should still have normal email.  Please write!

joe