(cba:news) Today's mystery, and stars for January

Joe Patterson jop at astro.columbia.edu
Fri Jan 4 05:47:28 EST 2013

Dear CBAers,

Here's a mysterious object in the morning mail!  Still not enough
information to figure out what astrophysical box to put it in... and might
be a pow'f'l interesting CV.

Here are some recommendations for early January.

GD 552.  Out of season... but still available to borealites, and a star
for which we are just about to ship off our long-term study.  It would be
great to obtain a couple weeks of LONG runs.

T Pyx. Similar story for the south.  Due mainly to Arto's and Berto's
Herculean efforts, we have the main (amazing!) result from our post-nova
timing study - a change in Porb by a whopping 0.006%.  Apparently
signifying a very large ejected mass, inconsistent with our theories of
recurrent novae.  I expect to have the paper ready in a month.  However,
there's some chance that this post-nova period is slightly *changing*,
which could greatly affect the interpretation. Another solid two weeks of
LONG runs could really nail this down - by delivering a very accurate
timing point at the end.  (dP/dt issues usually come down to "how long is
the baseline", and "how accurate are the timings at the start and end of
the data".)

DI UMa needs about another 3 weeks of coverage.  The most important issue
still on the table is: what is that period in quiescence?  Is it Porb, or
a negative superhump, or possibly a long-lived residue of the positive
superhump?  The *stability* of the period will help answer to this.  After
about 3 more weeks, the star will have spanned another quiescence, and we
might learn the answer.

We're done with PX And, MU Cam (for now), and PQ Gem (for now).  We could
definitely use more on RX0704+26, Swift 0732-13, and DW Cnc (need to go
long on the latter, since Pspin could get confused with Porb).

For northern observers who would like to specialize on one star, I
recommend BY Cam - arguably the king of the asynchronous polars.  This
positively needs a LONG campaign... but will definitely yield some nice
publishable results.

For the other ER UMa stars, I'll let Enrique give reports and advice.  Our
ongoing V1159 Ori campaign is definitely going GREAT, and should continue.
I'm not sure about the other three currently well-placed members: RZ LMi,
ER UMa, BK Lyn.

Good luck!


---------------------------- Original Message ----------------------------
Subject: [vsnet-outburst 14957] Re: [vsnet-alert 15238] OT
J122221.6-311525  = bright CRTS transient
From:    "Hiroyuki Maehara" <maehara at kiso.ioa.s.u-tokyo.ac.jp>
Date:    Fri, January 4, 2013 1:39 am
To:      vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp
         vsnet-campaign-dn at ooruri.kusastro.kyoto-u.ac.jp
         vsnet-outburst at ooruri.kusastro.kyoto-u.ac.jp
         vsnet-newvar at ooruri.kusastro.kyoto-u.ac.jp

 The object was detected at Vmag=11.8 by the Kyoto/Kiso Wide-field Survey
on Dec 26.

OT_J122221.6-311525 20120328.63044 <11.0V KW2 --
OT_J122221.6-311525 20120328.63083 <11.0V KW2 --
OT_J122221.6-311525 20120331.61500 <10.9V KW2 --
OT_J122221.6-311525 20120331.61535 <10.7V KW2 --
OT_J122221.6-311525 20120407.58847 <10.7V KW2 --
OT_J122221.6-311525 20120407.58882 <10.8V KW2 --
OT_J122221.6-311525 20120414.57725 <11.2V KW2 --
OT_J122221.6-311525 20120414.57762 <11.3V KW2 --
OT_J122221.6-311525 20120417.58544 <9.1V KW2 --
OT_J122221.6-311525 20120417.58581 <9.5V KW2 --
OT_J122221.6-311525 20120427.55866 <11.2V KW2 --
OT_J122221.6-311525 20120427.55903 <11.0V KW2 --
OT_J122221.6-311525 20120428.56146 <10.4V KW2 --
OT_J122221.6-311525 20120428.56181 <10.9V KW2 --
OT_J122221.6-311525 20120512.52359 <11.1V KW2 --
OT_J122221.6-311525 20120512.52396 <10.9V KW2 --
OT_J122221.6-311525 20121226.87655 11.844V KW2 0.245
OT_J122221.6-311525 20121226.87690 11.806V KW2 0.246
OT_J122221.6-311525 20121226.87741 12.020V KW2 0.273

KW2: Kyoto/Kiso Wide-field Survey
     f=105mm lens (F/2.0) + SBIG ST-8XME

On Fri, Jan 04, 2013 at 10:11:35, Taichi Kato wrote:
> OT J122221.6-311525 = bright CRTS transient
> SSS130101:122222-311525
http://nesssi.cacr.caltech.edu/SSS/20130101/1301010310804113661.html 12
22 21.63 -31 15 24.9 12.36 No SDSS object CV
>    No outburst was recorded in ASAS-3.
> ROSAT source:
> 122221.4 -311544 (2000.0) 1RXS-F_J122221.5-311545 0.050 0.75 0.05
> ===
> ATEL #4699							     ATEL #4699
> Title:	Detection of a Bright Optical Transient by CRTS
> Author:	A. J. Drake, S. G. Djorgovski, A. A. Mahabal, M. J. Graham,
> 		R. Williams (Caltech); R. McNaught (ANU); J. Prieto (Princeton); M.
> 		Catelan (PUC Chile); E. Christensen, S. M. Larson (LPL/UA).
> Queries:	ajd at cacr.caltech.edu
> Posted:	4 Jan 2013; 00:24 UT
> Subjects:Optical, Cataclysmic Variable, Transient, Variables
> Further to ATel#4678, here we report the CRTS discovery of
> <a
> This source was detected at V = 12.3+/-0.1 in four images taken by the
> <a href=http://www.mso.anu.edu.au/~rmn/>Siding Spring Survey</a>
> on 2013-01-01 UT and is located at RA=12:22:21.63 Dec=-31:15:24.9
> Based on 230 measurements (from 90 nights of observation between Aug. 2005
> and Aug. 2012), the
> object has an average magnitude of V ~19. The source exhibits variability
> at the
> level of ~1 magnitude in this archival data, yet shows no prior outbursts.
> The source is well detected by GALEX (with NUV =18.9+/-0.1 and FUV
> and may match ROSAT X-ray source 1RXS J122221.5-311545.
> The object is also a very good positional match to radio source NVSS
> However, it is no clear source is seen in radio observations from the SUMSS
> and VLSS
> surveys.
> This large, bright outburst, along with the UV detection and correspondence
> with an X-ray
> source, are most consistent with a cataclysmic variable. However,
> with
> a radio source is generally unexpected for CVs and may be coincidental
> or spurious.
> Further observations are required to determine the nature of this event.
> A finding chart is available
> <a

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