(cba:news) late january stars

Joe Patterson jop at astro.columbia.edu
Mon Jan 23 10:11:32 EST 2006

Dear CBAers,

As I mentioned last time, V1193 Ori and SDSS0407-06 have been spectacular
winners this month... but V1193 Ori stays reasonably constant, while
SDSS0407 ("Eri") is showing high and low states - presently high - with
the superhump and orbital waveforms dependent on state.  This means that
following the latter takes more work - and I'd love another 10 days on

Other evening-only targets should be abandoned: AO Psc and FO Aqr.

Then there's the newly discovered dwarf nova ASAS0233-something. This has
been covered somewhat heroically - in view of the sky position - by Berto
and Major Tom.  No superhumps yet... and I'm tempted to say forget it,
it's just too far west and interferes too much with known winners
(namely, Eri).  However, if you have a nice western horizon and nice skies
and are attracted to long shots... OK, this might be up your alley. Tom's
data looks pretty good, and with multiple longitudes we might even be able
to find the period.  For lesser mortals, I'd say no go.

Somewhat later on at night, I always advise quitting on HS0506+77.
Coverage by Tonny and Bart Staels suggests that photometry isn't going to
yield strong periodic signals.

It is, however, time for another few weeks on FS Aur.  We're trying to
track the 3.4 hr photometric signal over years... and having gotten early
season data, we now want to secure late-season "bookend" coverage to
establish cycle count over a very long baseline.  Good northern target for
the next few weeks!

And there's a most-of-the-night counterpart in the south, namely T Pyx. We
need a couple more weeks coverage to establish a yearly orbital minimum
(it's so weak that random flickering dominates the nightly light curves,
but averaging brings out the true waveform).

The new targets I recommend are:

NORTH ONLY.  UMa 6 = H0928+50.  This is a 10-hour eclipsing binary with no
established ephemeris.  A few orbits of 2006 coverage will establish its
long-term ephemeris - and make a nice little publication for you (I'll
send you all our previous data).

SOUTH AND NORTH.  Hya = RX1050-14.  You bet!  A tough target (faint star
and fairly low amplitude) but it should be doable.  We got just enough
data last year to suggest that a long program will establish its basic
period structure - but not enough to actually succeed.  That's left for
this year... I'm awfully psyched for this very nearby and probably very
old star.

Not a very big menu - gives us a better chance of doing a fine job with
each star!


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