From jop at astro.columbia.edu  Thu Oct 23 11:14:30 1997
From: jop at astro.columbia.edu (Joe Patterson)
Date: Thu, 23 Oct 1997 11:14:30 -0400 (EDT)
Subject: (cba:news) Old and New Friends
Message-ID: <199710231514.LAA19561@tristram.phys.columbia.edu>


Dear CBAers,                                           Oct. 23, 1997.

     Well the leaves have been falling off those northern trees, and
indeed we have assembled a wonderful collection of PX And data.  Long
runs on nearly every day for a month, and plenty of longitude leverage.
This is basically as good as we can do.  I believe it's time to bring
down the curtain on the star for the year.  My guess is that anything
we are going to ever see is probably in the data already.

     Two other really good, and bright, stars for attention in the
northern sky now.  TY Psc just erupted, and at this exact moment it
looks like it will be a superoutburst, although that could change in a
day or two.  If you find it still bright, then yes, it's a definite
superoutburst.  The star is known to show superhumps but only a
very coarse period is available.  We'd like to cover it thoroughly
for 7-15 d and find a precise value.  By the way, that's the Fish, not
the Southern Fish which alas also has a superhumping dwarf nova named
TY.

     In theory, our priority for "normal" dwarf novae (whatever that
means; anyway TY Psc seems pretty normal) is low.  That's why we don't
jump really fast, or at all, on the stars announced in superoutburst.
The exception here is to refine that superhump period.  A precise
measure of fractional period excess over Porb is one of the numbers we
cherish most!  We also make exceptions for the very rare erupters (WZ
Sge stars and candidates), mostly because the eruptions are so rare,
and partly because the period excesses seem to be interestingly small.

     The other star for intense coverage now is V592 Cas.  Spectroscopy
shows a short orbital period, and there's good evidence now that a
similar period appears strongly in the light curve.  It's available
basically all night long for borealites.  At magnitude 12.8 we can all
get superb data on this little star.  I believe this star should be our
prime target for the next month.  It's in both editions of Downes and
Shara, at (2000) 00 20 52.4, +55 42 17.

     A short paper reporting the Porb of AM CVn was submitted, and is
also on our website now.

     Every morning when I walk to work, I see Orion hangin' up there in
the south.  That tells me that CN Ori is back in town.  Can't say the
same about Leo Minor, but a little calculation shows that RZ LMi is
also back in the morning sky.  These are prolific superhumpers, and our
data suggest that superhumps *remember phase* from one outburst to the
next.  We need to nail this down!  They each erupt about every 20 d, so
will have 8-9 eruptions during a season; we'd love to time superhumps
in each eruption and see if this remarkable allegation is in fact true!
See what you can get.

     I hope that Australites can keep the faith on AH Men = H0551-819 =
"Men 1".  At -81 degrees it certainly keeps the faith on you!


              joe