(cba:news) stars for may

Joe Patterson jop at astro.columbia.edu
Tue May 6 08:03:59 EDT 2008

Dear CBAers,

The flowers are blooming, the Red Sox are in first place, U Sco is ready 
for an outburst, the DQ Her ephemerides are under control.  Even the 
fleas are back.  It must be a new season... and time for a wholesale 
change of targets.

Barring a dramatic eruption, I'd like to take advantage of the new moon 
and focus on some pretty faint stars now.  In particular:

1. GW Lib.  This is still slowly declining, I think, from its 2007 
eruption... but is probably about 16.3 now.  Manageable in decent 
weather.  It has never been observed in a fresh postoutburst state, and 
there are a host questions: is there an orbital signature? are the 
white-dwarf pulsations back? and what about the strange 2.1 hour 
photometric signal (that still defies explanation)?  This is an IDEAL 
target for southern observers at all longitudes - and as long as 
possible each night, to distinguish among aliases and to increase 
resolution.  It's also good for ambitious observers in the southern USA 
(Tom, you know who you are), since that's a critical longitude.

2. SDSS1238-03 (Vir).  No eruption, but we had good luck tracking the 
8-hr variation in 2006, and it too remains a mysterious beast since Porb 
is known to be very short.  For southerners, this mostly conflicts with 
GW Lib, so take one and stick with it.  It's a little fainter, about 
17.5... but the variations are likely bigger.  Good for all latitudes, 

3. Oph (1730-05).  A favorite DQ Her star newly arrived in the sky. 
V=16, can be a quasi-backup target.

4. SDSS1502+33 (Boo). A deeply eclipsing star V=17.6.  See if you can 
get it; a faint-limit test for northern observers.

5. SDSS0804+51 (Lyn).  Still available as an evening target for 
northerners. Need some more pulse timings.

6. Finally, WX Cen (1312-63).  Bright-star backup for southerners.  We 
need another season to complete a period study.  Pretty nice photometric 

Meeting notes:

* the Big Bear meeting is coming up over Memorial Day weekend.  I won't 
be there but there's usually a CBA contingent (Jerry Foote and Bob Koff 
are regulars).

* I will attend the early-January meeting in Hawaii, and hope to see 
some of you.

* And next year is an AAVSO meeting which I'm likely to declare as a CBA 
meeting also.  See AAVSO site for details.

*Also, Tonny and Bart, could you give a report on the BAA-AAVSO meeting 
in April?

Happy observing!


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