september stars

From: Joe Patterson <*jop_at_astro.columbia.edu*> Date: Thu, 8 Sep 2005 10:11:46 -0400 (EDT) · jop_at_astro.columbia.edu

Dear CBAers,

Many changes in the offing this month.  Not the least of which is - I get
back to work!  First classes this week.  I suppose summer should in
principle be the time when we get most of our research done... and I
faintly recall this being so a long time ago.  But no more.  I think just
the discipline of regularly going to an office and plopping down at a
desk.

The AE Aqr campaign is finished, so any data you haven't submitted would
be nice to see now.  (Actual publication is, as usual, a year or so away -
but as the analysis grinds through, it would be good to have a stable set
of original data.)

Ditto for V1082 Sgr.  Jennie and Berto worked hard on this one, but it's
too early to say what's in it - and too late in the season to keep it
going.

Four other stars need to be scuttled on grounds of insufficient interest:
MN Dra, V1327 Aql, V1006 Cyg, V632 Cyg.  Like unpopular politicians and
movies, poor ratings sink stars on our list, even if nothing else does.

We carried out decent - though not excellent - campaigns on IX Dra (mostly
Lew Cook) and V1494 Aql (mostly Bob Rea).  These stars will be obvious
winners in a future year - presumably next - when we can get very dense
global coverage.  For the latter we can derive a stable long-term
ephemeris, once we tie all the years together.  They're also sinking too
low in the west - so away eith 'em!

A really rewarding star on the present menu is HS1813+61 ("Dra" in the
Downes catalogue).  Dave Messier has been taking advantage of the
post-Katrina spell of beautiful weather in the northeast U.S. to get long
runs on this star.  It has a beautiful negative superhump at ~3.4 hrs, and
probably a "disk wobble" period at ~3 d.  Another week or two of coverage
- say till the next bright moon - would really nail this one to the wall.
Borealanders, fire away!

VZ Scl looks very promising in the south, too.  Not too much yet - mostly
from Alon Retter/Alex Liu - but the star shows deep eclipses and large
orbital or quasiorbital humps.  Right up our alley!  Definitely the prime
target for good nights now in the south.

EC 21178-5417 ("Ind" in the Downes catalogue) is a good secondary target -
about 13.5 versus 15.7 for VZ Scl - since it's bright and can survive more
moonlight and clouds.  Another deep eclipser.  The world doesn't know too
much about either of these stars, although VZ Scl has been squatting in CV
catalogues for many decades.

New northern targets.

"Cep 1" = GD 552.  We have a long-term
spectroscopy-photometry-astrometry-alchemy campaign just about to wrap up
on this fascinating star, possibly the oldest of all CVs.  One more season
of photometric coverage will bring the concoction to a perfect state.
Nominally a "noneruptive" CV, though you'll notice some burps and
hiccoughs going on in the light curve.  About 16.5, needs a decent night.

HS 2331+3905 = "And".  Same general story, though the star's a bit
brighter at 15.6.  Many fascinating periods in its light curve!

LS Peg.  At V=12-12.5, this is a great  target for nights of lesser
quality.  We did a great campaign in fall 02, and want to update the
periods and check for long-term stability.  Another season will finish the
job.  BTW at +14 degrees dec, this is plenty suitable for southern
observers.

And FO Aqr and AO Psc remain good backup targets - bright and not needing
(as most of our targets do) long coverage!

Joe