From jop at astro.columbia.edu  Fri Sep  2 14:51:01 2011
From: jop at astro.columbia.edu (Joe Patterson)
Date: Fri, 02 Sep 2011 14:51:01 -0400
Subject: (cba:news) stars for september
Message-ID: <4E612595.2030307@astro.columbia.edu>

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From jop at astro.columbia.edu  Mon Sep  5 21:22:10 2011
From: jop at astro.columbia.edu (Joe Patterson)
Date: Mon, 05 Sep 2011 21:22:10 -0400
Subject: (cba:news) OT J184228.1+483742: 11.8 mag transient
Message-ID: <4E6575C2.9050707@astro.columbia.edu>

Dear CBAers,

This message from vsnet calls attention to a new transient which may 
well be a dwarf nova.  At 12th magnitude, it might be a very nice 
target.  If we can muster observations on both sides of the Atlantic, we 
should be able to define the period content satisfactorily.  Assuming it 
does have periodic variations.

Fire when ready!

joe

-------- Original Message --------
Subject: [vsnet-alert 13644] OT J184228.1+483742: 11.8 mag transient
Date: Tue, 06 Sep 2011 09:06:12 +0900
From: Taichi Kato <tkato at kusastro.kyoto-u.ac.jp>
To: suuma at yahoogroups.com, variable_star_forum at yahoogroups.com, 
vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp, 
vsnet-alert at yahoogroups.com, 
vsnet-campaign-dn at ooruri.kusastro.kyoto-u.ac.jp, 
vsnet-newvar at ooruri.kusastro.kyoto-u.ac.jp, 
vsnet-newvar at yahoogroups.com, 
vsnet-outburst at ooruri.kusastro.kyoto-u.ac.jp, 
vsnet-outburst at yahoogroups.com, wzsge at yahoogroups.com

OT_J184228.1+483742

    Nishimura-san has detected a bright transient.  There was a 20 mag
star at the position of the improved astrometry.  The object appears
to be a high-amplitude WZ Sge-type dwarf nova.
All sorts of observations are encouraged!

http://www.cbat.eps.harvard.edu/unconf/followups/J18422792+4837425.html



From jop at astro.columbia.edu  Wed Sep 28 08:38:21 2011
From: jop at astro.columbia.edu (Joe Patterson)
Date: Wed, 28 Sep 2011 08:38:21 -0400
Subject: (cba:news) BW Scl, V1432 Aql, V1500 Cyg, BY Cam
In-Reply-To: <385373658.7385201317198769011.JavaMail.root@marjani.telenet-ops.be>
References: <385373658.7385201317198769011.JavaMail.root@marjani.telenet-ops.be>
Message-ID: <4E83153D.1070604@astro.columbia.edu>

Hi Josch et al,

The paper is submitted, but not yet accepted.  I suspect that it will be 
soon... in which case, 2011 data wouldn't get in.  However, we learned 
enough about the star, and in particular identified enough of its 
mysteries, that I'd expect 2011 coverage - assuming we can get close to 
round-the-world time series - will furnish a fine follow-up paper.  By 
itself.  Really good coverage would enable us to investigate the *fine 
structure* in the periodic signals, which this star certainly appears to 
have.

The CD Ind campaign is going so well (even if it's over, due to the 
star's recent bashfulness) that I decided to wake up the "asynchronous 
polar" project.  We already have a great 2011 baseline for V1432 Aql. 
But it still has some life left in its observing season, and since it's 
roughly equatorial (-10) everyone can get at it briefly.  So that's a 
good one for another month.

This is a very small class of stars - and each needs frequent study to 
investigate the alleged 
slow-return-to-synchronism-after-a-nova-outburst.  Let's put two other 
members on our list: V1500 Cyg (the only known nova among them) and BY 
Cam.  Both highly northern of course, but
both accessible this time of year.  They do require pretty long time 
series (3+ hours, and 3++ would be even better).  And V1500 Cyg might be 
challengingly faint.  But potential rewards are great.

The class is so small that every single member is of great interest in 
itself.  Sort of like superhumps were in the late 1970s.  And a 
wide-open field too.  Good luck with it!  BTW a Columbia student is 
doing a senior thesis on this, so might be writing to you re your data.

joe


On 9/28/2011 4:32 AM, hambsch at telenet.be wrote:
> Hi Joe,
>
> Ok, I will keep CD Ind on my agenda and once in a while look it up.
>
> BW Scl and VZ Scl could be covered (maybe even simultaneously).
> You mentioned a recent paper. Is this already published or not yet submitted and the upcoming data could still be included?
> I could try a 1 min on BW Scl for a couple of hours after the star does its meridian flip.
>
> Regards,
>
> Josch
>
> ----- Originele e-mail  -----
> Van: "Joe Patterson"<jop at astro.columbia.edu>
> Aan: cba-chat at cbastro.org
> Verzonden: Woensdag 28 september 2011 03:53:06 GMT +01:00 Amsterdam / Berlijn / Bern / Rome / Stockholm / Wenen
> Onderwerp: Re: (cba:chat) CD Ind
>
> Hi Josch, Robert et al,
>
> OK, I bow to your judgment on this one. I've been marvelling at that
> great data you've been sending... but 19.5, well, that seems to be just
> a little too ambitious. Take an occasional peek to see if it comes back,
> though; the light curves are quite beautiful at 17.5.
>
> The ideal southern target now is BW Scl.  We recently finished a paper
> on this star... but right about now is the perfect time of year, and
> with Josch's telescope we have the chance to get true 24-hour coverage.
>    At 16.6, the star's bright, and it almost always shows a sheaf of
> interesting periods - including some strange ones: a superhump at Porb +
> 10%, and a 10-minute signal that might, or might not, be WD pulsation.
> It has been oddly neglected over the years.  It's sort of the southern
> WZ Sge - but better, since it flashes a more complete set of periods.
>
> Hmmm, maybe the southern V455 And would be a better comparison.  Well,
> no need to quibble - there are many fine stars up there!
>
> VZ Scl is also promising, assuming it's in the bright state (15-16).
> Only once did we carry out a few-day observation of it, which was
> inconclusive.  Other than the eclipses of course.
>
> joe
>
>
> On 9/27/2011 4:27 PM, Josch Hambsch wrote:
>> HI,
>>
>> I see that Robert Rea did CD Ind last night. What is the present magnitude of this star? The last time I observed it it was below Mag 18.
>> Did it brighten again? Is it worthwhile to continue observations?
>>
>> Regards,
>>
>> Josch
>>
>> http://www.astronomie.be/hambsch
>> ____________________________________________________________
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