Southern stars, and WZ Sge

From: Joe Patterson <*jop_at_astro.columbia.edu*> Date: Fri, 28 Sep 2001 12:53:18 -0400 (EDT) · jop_at_astro.columbia.edu

Dear CBAers,

As most of you know, WZ Sge has probably settled into its final decline
now.  (Actually, it'll probably have about thirty million more final
declines in the next Gyr - but with our characteristically parochial
viewpoint, humans like to call it final.)  It's at V=13.8 and slowly
fading.  Slightly harder to observe now because of the onrushing western
horizon, and the possibly obstreperous companion.

Thanks to all your efforts - and thanks to the serendipidity of a *July*
eruption! - we definitely have the most exquisite photometric record ever
of a dwarf nova in superoutburst.  I am having a grand old time marvelling
at the intricate periodic structure of these humps.  To my delight, we've
done at least as good a job exploring that intricate structure as we did
on AM CVn 2 years ago.  I didn't think we ever could for a dwarf nova -
they tend to not stand still long enough to permit very accurate
measurement.  WZ Sge didn't stand any more still than any other star, but
because of observer tenacity - and in part because of the Halley's
Comet-like publicity machine that the star enjoys - we made up for it.
I expect to get the paper sent off in another 4-6 weeks.  In a few days we
hope to get the observing log posted on the web; that'll enable you to
check whether all your submitted data got through OK (in addition to the
electronic thanks).

Although the outburst is mostly over, we'd like to keep coverage alive for
about 3 more weeks.  The superhump, you see, is still going strong.  As
usually happens in the best-observed stars, the superhump greatly outlives
the outburst that spawned it.  A feature of dwarf novae not yet
understood, and we hope to make progress on it by watching our superhump
slowly die over the next few weeks.

So the best object for NORTHERN COVERAGE is still WZ Sagittae.  Stay
motivated!  The backups are the DQ Hers: FO Aqr, AO Psc, V709 Cas.  But of
course... if GD 552 = Cep 1 erupts, then quit your job, sell everything
you have and give to the poor (except your telescope and computer), and
dedicate your life to the star.  V1251 Cyg too, but not as extreme (do
consider quitting your job, however).

Southerners gave up on WZ Sge a long time ago, murmur, murmur.  Bob Rea,
Fred Velthuis, and Jennie McCormick have been doing a good job dodging
NZ clouds and hitting V1223 Sgr and FO Aqr.  But it's a good time to
switch southern stars.  There are THREE new southern stars deserving of
center stage.

The first is BW Scl = RXJ2353.0-3852.  Mag 16.5, we'll be studying it
intensively from Chile next month.  Probably a dwarf nova, though no
eruptions ever observed. 23 53 00.70 -38 51 45.6.  Strong waves in the
light curve, let's explore 'em!

If that star's too faint, then I recommend EC23593-6724, a 14.3 mag star
at (1950 coords 23 59 21.7 -67 24 28) which is a short-period CV of
unknown type.  Another star we plan to observe from Chile.

Finally there's EC05114-7955, a 15 mag star with P near 3 hr.  Lots of
cool photometric activity, very friendly dec, many things left to learn!
(Practically everything.) 1950 coords 05 11 25.1 -79 55 02.

So let's see what the cats can drag in!

     joe