(cba:news) March stars

Joe Patterson jop at astro.columbia.edu
Wed Feb 28 11:44:36 EST 2001

Dear CBAers,

Further update on targets for photometry:

                     SOUTHERN STARS

   A couple weeks ago, Robert Rea and Maria Marsh brought our
TW Pic campaign to an end, basically by blanket coverage
which will never be improved! (Except possibly from multiple
longitudes.)  Now they have done the same for RR Pic.  The
results of the two campaigns were virtually opposite: TW Pic
is obviously a long-period star (Porb in the range 6-10 hr)
with an extraordinarily complex power spectrum, while RR Pic
is a 3.5 hr star with a very stable light curve and power
spectrum.  The data in hand are sufficient - we can let
theses stars rest in peace for a few years.

   With its enormously long observing season, AH Men (=Men 1
=H0616-81 =H0551-819) is now the best southern target.  We've
had campaigns in some previous years, but never with the very
strong NZ/AU coverage we have now.  It appears to have THREE
closely spaced periods, representing Porb and positive and
negative superhumps.  We'd like to track the signals
continuously for a few months, and see how the two humps
change in amplitude as the disk flails about and wobbles.

   The other southern (actually equatorial) target is SW Sex,
the prototype of the SW Sex stars.  We've still not carried
out a significant search for humps in this famous but elusive

                      NORTHERN STARS

   Northern nights are still long, but some of our heaviest
North American artillery (Daves East and West, and Cap'n Bob)
have been off the air for various reasons.  Yesterday I
received the magic coded message from Dave East - "Sats in
the can".  Like other famous coded messages of the past
("Climb Mount Niitaka", "The Italian navigator has discovered
the new world"), this one carried the essential data - and
also released CBA-East for its customary tasks.  So we'll
do a better job now helping Tonny and Brian Martin and John
Stull keep watch over the northern sky.

   Tonny and Brian have done a good job on CP Dra, the newly
discovered dwarf nova.  This is definitely an interesting
star to follow for a while.  I presume it will soon fade from
visibility, but keep up the good work!

   The RZ LMi campaign is going well in superoutburst
(gorgeous humps, data available on request) but not so well
in quiescence - still haven't got the needed coverage in
quiescence.  Let's keep the faith!

   Finally there's BP Lyn = PG0859+415 = Lyn 1.  Still no
data at all on this star.  But as an eclipsing SW Sexer, it
is a prime candidate for great superhumps.  Still some time
to move on this guy.

   And SW Sex itself, it would be a fine time to begin coverage
of this star.  As usual, the best approach is to select one of
these stars and hang onto it until it surrenders (or we surrender,
or you surrender).

So:    AH MEN  and  SW SEX  in the south 
       CP DRA, RZ LMI, BP LYN, SW SEX  in the north


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