From jop at astro.columbia.edu  Sat Jun  5 09:20:23 2010
From: jop at astro.columbia.edu (Joe Patterson)
Date: Sat, 05 Jun 2010 09:20:23 -0400
Subject: (cba:news) OT_J112253.3-111037 = CSS100603:112253-111037,
	among others
Message-ID: <4C0A4F17.8090802@astro.columbia.edu>

Dear CBAers,

Another Catalina transient with excellent credentials for joining the SU 
UMa club.  Tom's photometry last night, at V~14, showed quite nice 
humps, and at an interestingly short period.

Not the greatest sky position for June (Crater)... but close enough to 
the equator that we might be able to patch together a round-the-world 
light curve that will reveal the precise period structure.  Yet another 
new toy in the southern sky.  The others of very high merit right now 
are GW Lib and RX1654-19.  All are flashing quite fascinating - and new! 
- periodicities in their light curve right now.  It's usually 
advantageous to "stick with one star" as long as it's available in the 
sky... but the new dwarf nova is a transient object, plus it's 
disappearing in the west (both points raising its priority, maybe).

And of course don't forget OT2138+26, the new dwarf nova in Pegasus. 
*Very* inconveniently placed, but this star is not only new but 
*nearby*.  Such stars have a high impact on CV science; the fact that 
we're still discovering new CVs within 100 pc or so is evidence that a 
lot of stars are still hiding!

joe


-------- Original Message --------
Subject: [vsnet-alert 12020] OT_J112253.3-111037 = CSS100603:112253-111037
Date: Thu, 3 Jun 2010 16:01:17 +0900
From: Hiroyuki Maehara <maehara at kwasan.kyoto-u.ac.jp>
To: vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp, 
vsnet-outburst at ooruri.kusastro.kyoto-u.ac.jp, 
vsnet-campaign-dn at ooruri.kusastro.kyoto-u.ac.jp, 
vsnet-newvar at ooruri.kusastro.kyoto-u.ac.jp

  The CRTS (Drake et al. 2009, ApJ, 696, 870) detected a bright (14.3mag)
optical transient CSS100603:112253-111037 at R.A. = 11 22 53.33,
Decl.=-11 10 37.2.

1006030090614101504 2010-06-03T04:05:44 2010-06-03T03:56:53 11 22 53.33 
-11 10 37.2 14.32 14.32 14.29 14.30 
http://nesssi.cacr.caltech.edu/catalina/20100603/1006030090614101504.html

  The object has a faint blue counterpart (~ 20 mag) in the SDSS photometric
catalog and the USNO B-1.0 catalog. The object is likely a large-amplitude
dwarf nova in outburst.



From jop at astro.columbia.edu  Sun Jun 20 00:01:56 2010
From: jop at astro.columbia.edu (Joe Patterson)
Date: Sun, 20 Jun 2010 00:01:56 -0400
Subject: (cba:news) stars for the solstice
Message-ID: <4C1D92B4.4080703@astro.columbia.edu>

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From jop at astro.columbia.edu  Tue Jun 22 16:10:12 2010
From: jop at astro.columbia.edu (Joe Patterson)
Date: Tue, 22 Jun 2010 16:10:12 -0400
Subject: (cba:news) TY Vul and V1084 Her (RX1643+34)
Message-ID: <4C2118A4.4070703@astro.columbia.edu>

Dear CBAers,

Richard Sabo just sent me a night of data on TY Vul - clear, strong 
superhumps at a period about 2 hours.  First time ever!  Fire at will.

Lots of northern dwarf novae peppering the predawn summer sky.  Best to 
pick one and stick with it, usually.  I'll try to keep everyone posted 
on the ups and downs of each.

Speaking of which... two other stars I failed to report on a few days 
ago.  A few of you (led by Bill Goff) have tackled our hardest target 
star, sdss 1339+48.  Bill's observations do show the pulsations, which I 
wondered about.  But they, along with the big-telescope data which 
preceded it, also show that the pulsations are not stable over baselines 
greater than a few days.  In fact, I suspect that this is true of all 
the GW Lib stars.  It means that long campaigns don't reap uniquely 
valuable rewards - revealing tiny rates of period change, for example. 
So let's put sdss1339 aside.

And for the same reason... let's resurrect V1084 Her = RX1643+34.  I've 
now analyzed all 2010 data on this bright novalike - and was somewhat 
amazed to find the negative superhump at *exactly* the same frequency as 
in 2001.  Generally one doesn't expect disk precession to show a good 
clock; none of the others do.  So now this object is (somewhat) uniquely 
curious, and it's bright enough to be a good target for maybe 2 more 
months.  Good northern evening target, or all night if you'd like a 
bright target.  Try to use star #2 of Mickaelian et al. 2002 as your 
comparison (V=12.97).

V1084 Her is near V795 Her in brightness, coordinates, and reason to 
observe.  You'll probably want to pick one or the other... but the more 
sure winner right now is V1084.

joe