(cba:news) mid-March stars

Joe Patterson jop at astro.columbia.edu
Sun Mar 12 07:42:14 EST 2006

Dear CBAers,

Time for another round-up of once and future loves among the CVs.

Two stars to delete from the menu (you did anyway) are RX0022+61 and
SDSS0804+51.  By virtue of sunlight and return to quiescence, these stars
are retired for the year.

Little Swifty (Swift0732-13) is going great guns: still lots of great data
coming in from NZ, and from Arkansas too.  A recent ATel resolved the star
into two - a faint blue star which is the true Swifty, and a crowding star
1.8" away which tends to dominate at R and I (and explains the apparent
flatness of the raw light curve).  This is not a huge nuisance to us since
the periodic variations are more or less different to contamination by a
constant light source... but if you happen to have a blue filter, that
would be helpful!  Otherwise, just carry on for a couple more weeks.

It's getting a touch late for DW Cnc, but I very much want a few more
weeks of coverage - to nail down the somewhat subtle periods for the year.
A good evening target for borealites.

I had great hopes for RX1039-05 and WX Pyx a month or two ago.  These are
admittedly quite faint stars (17-18) but the periodic signals are VERY
LARGE, and I'm guessing that many of you guys can get quite acceptable
data if the skies are clear.  Still around for another month or two - give
it a shot.

The other faint star I wanted to endorse is RX1050-14, available to both
hemispheres.  I don't promise much for this guy though - its photometric
signals are pretty weak.  If it erupted it would be ENORMOUS news - so
keep an eye on it.  A few get-acquainted time series would be good too.

The bright targets for the two hemispheres are these.  WX Cen in the
south; we'd like to evaluate it for membership in the supersoft-binary
class.  And AM CVn in the north.  This is the beginning of what I expect
will be a long season of AM CVn coverage.  My main goal is to study the
weak orbital signal (1028 s), which past data suggests is shortening on an
astrophysically interesting timescale.  I'm pretty sure that a final
season's coverage will nail this result down.  It's also true that this
star always throws surprises at us - let's keep a close watch and keep
ourselves open to those surprises!

I'll write again in a few days.  A week off from the pressures of classes
and exams - what a pleasure!


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