may-june targets

From: Joe Patterson <*jop_at_astro.columbia.edu*> Date: Sat, 29 May 2010 23:34:14 -0400 · jop_at_astro.columbia.edu

Dear CBAers,

Well, EX Hya went like a tornado, as is its wont.  And V1032 Oph has 
long since faded.  And it's time to draw the curtain on CR Boo.  So 
let's switch to a new menu for June.

The erupting and eclipsing dwarf nova in Lynx ("Lyn" in Downes catalog, 
or SDSS0903+33) would be a great target for about one more week. 
Enrique de Miguel has been fighting alone on this one; he has found 
excellent superhumps - now we need some USA coverage to nail down the 
period precisely!  Not in the sky long - you can close the telescope in 
time for the late news!

The new dwarf nova in Pegasus (OT2138) will remain interesting as long 
as it's bright enough to observe.  Not very well placed of course... and 
of course the undesired companion star will get annoying as the star 
fades.  But we manage to do OK with splices from Spain and New Mexico, 
among others.  So we're managing to keep decent track of the evolving 
outburst.  Lots of room for improvement there!

I've received several runs now on SDSS1339+48, a CV with a pulsating 
white dwarf.  To my delight, Bill Goff is able to detect these 
pulsations with a 14-inch telescope - even with a dead-full moon in the 
sky!  So we can find 2% signals on V=17.5 stars in full moon - verry,
verry nice.  This star is worth tracking a few weeks, or until it 
proves/disproves its basic coherence.

An even better target of the same ilk is GW Lib, and I really HOPE that 
some North American observers - as well as our usual stalwarts in 
ZA/AU/NZ - can contribute to this star's record.  I promise to analyze 
the data immediately and comment.  The pulsations may or may not be 
present, but the other main target is the 2.1/4.2 hr variation that has 
become slightly famous - and remains unexplained.

So far, no takers on V4743 Sgr.  We have quite good coverage on it 
through last year - just need a few more timings to conclude the study.
Well placed for you australites.

The bright northern target this season is V1084 Her (= "Her" in Downes 
catalog).  We started it last month, then the dwarf novae started 
popping off.  Time to go back into the water.  Also, a target I highly 
recommend in the post-midnight sky is GD 552 (= Cep 1).  I'd love to 
start the GD 552 season about now (and Helena will get 1-2 runs with the 
2.4 m).

Buena suerte!

joe

Finally, there's GD 552 = Cep 1.  Available to northerners after 1 a.m.
Let's begin the GD 552 observing season!
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