(cba:news) meet SDSS1238-03

[Joe Patterson]

Hi CBAers,

Olde Whiteface has moved mostly outa the way, and I'm feeling lucky...

For the past 2 days we have been monitoring SDSS1238-03 from Kitt Peak.
The light curve is very remarkable.  There's a signal near 38 c/day which
probably signifies the orbit (=2 nu-orb, perhaps).  There's also another
signal near that frequency, which must have a different origin (unknown).
But then there's a very large amplitude signal (~0.4 mag) with a period of
about 10 hours.  It's too early to tell whether the latter is really
stable, or for that matter whether any of these signals are.  But the
power spectrum is certainly tantalizing.

Because of its location on the celestial equator, no one can get long runs
on this star from any fixed location.  It's really a prime target for CBA
coverage, except for its faintness (V~17.3).  But the amplitude of the
low-frequency signal, and maybe even ALL the signals, is pretty high...
and the Moon no longer interferes in that part of the sky.  So my guess is
that many of you can get a decent light curve on this star if the sky
conditions are good.  It's really NECESSARY to have multi-longitude
coverage, if we're ever going to understand that low-frequency signal.

Can you give it a try?  Our Kitt Peak run continues for a while... so
we're vitally interested in any help we can recruit, especially from
exotic longitudes, on this star.

It's labelled "Vir" in the Downess catalogue, and I think goes by the full
name SDSS J123813-033933.  Good luck with this fascinating star.

joe