(cba:news) stars for may
jop at astro.columbia.edu
Tue May 6 08:03:59 EDT 2008
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
* 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
* 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
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