From jop at astro.columbia.edu  Sat Nov 19 13:26:49 2011
From: jop at astro.columbia.edu (Joe Patterson)
Date: Sat, 19 Nov 2011 13:26:49 -0500
Subject: (cba:news) stars for nov-dec
Message-ID: <4EC7F4E9.4030608@astro.columbia.edu>


Dear CBAers,

BW Scl has come down from its plateau, and is now at 14.6 - 2 mag 
brighter than quiescence.  Some echoes may happen soon - it's a bit 
surprising that they haven't happened yet.  On the other hand, it's the 
first outburst ever, so maybe it's erroneous to "expect" the echoes. We 
are getting superb coverage from Josch Hambsch, and good support from 
Berto and Bob Rea.  Keep it up for a few weeks; the superhumps are going 
strong and flashing some interesting (though not yet decipherable) effects.

A popular northern star this season has been RX2133+51 ("Cyg"), with Tom 
and Enrique as the main perpetrators.  It's a DQ Her star, and the 9.5 
min pulsations come in like gangbusters (American expression).  But 
there's another strong signal, at 3.56 c/d.  This is a country mile 
(another American expression) separated from the known orbital frequency 
of 3.36 c/d.  It's the usual signature of a *negative superhump*.  But 
it's occurring in a binary of unprecedentedly long Porb (surprise #1), 
and it's FULLY COHERENT (in phase, not merely period) over our 500-day 
baseline (surprise #2).  This is fascinating to me.  We never have 
really studied the negative-superhump phenomenon for dependence on Porb 
- and maybe it obeys a quite different law from the positive guys.

This suggests a few new targets for study.  One is V378 Peg (PG2337+30). 
  It's bright, still in season, and Fred Ringwald's recent preprint 
seems to prove that it has negative superhumps.  And to suggest that 
they may be phase-coherent over a very long interval.  This is a 
wonderful target for us northerners.

TV Col (2A0526-328), a 5.5 hr binary reported to have a 6.3 hr 
photometric period.  (A + superhump, of course, but that would be mighty 
interesting at Porb = 5.5 hr.) We've made a few efforts to 
confirm/reject this period, but they haven't been decisive.  With better 
representation in the Southern hemisphere (hoping for help from Arto or 
Josch at the Atacama telescope farm), let's give it a really good effort 
now!

And one more, along these lines.  There's a fascinating paper by Schwarz 
et al. (2007, A&A, 473, 511) on RX J0524+42, also called "Paloma".  It 
seems to have a raft of periods around 2.5 hours.  Now this target is 
near V=17.5, but the amplitudes of variation are quite large (up to 1 
mag), and I think it qualifies as CBA-eligible.  At least for those with 
a little extra by way of aperture or courage.  This paper has been 
strangely ignored (by me, too)... but it's pretty damn fascinating! 
J2000 05 24 30.52, +42 44 50.4.

A few stars to retire.  (1) RX2133 - we have enough now.  (2) BY Cam - 
for about a month; we have GREAT coverage, from Enrique and Bob Koff, 
but we can postpone for 4-6 weeks, then resume to get a very accurate 
period (or [periods?). (3) RX0636+35 - also for 1-2 months, then resume 
to narrow down that period.

For DQ Her pulse maintenance, the good stars to do now are: DQ Her, 
IGR0023+61, V1062 Tau, and WX Pyx.  A touch more RX0704+26 would be nice 
too.

Can anyone get a time series on T Pyx yet?  Chop down those trees, and 
give it a try!

joe


From jop at astro.columbia.edu  Tue Nov 22 22:00:06 2011
From: jop at astro.columbia.edu (Joe Patterson)
Date: Tue, 22 Nov 2011 22:00:06 -0500
Subject: (cba:news) [vsnet-alert 13881] PR Her very bright  outburst
Message-ID: <4ECC61B6.4050106@astro.columbia.edu>

Hercules is mighty tough this time of year, but with help from a range 
of longitudes, we might be able to stitch together a good time series. 
It certainly has the potential to be an interesting star!

joe

-------- Original Message --------
Subject: [vsnet-outburst 13469] Re: [vsnet-alert 13881] PR Her very 
bright  outburst
Date: Tue, 22 Nov 2011 19:38:57 -0700
From: Tom Krajci <tom_krajci at tularosa.net>
To: Taichi Kato <tkato at kusastro.kyoto-u.ac.jp>
CC: wzsge at yahoogroups.com, vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp, 
vsnet-outburst at ooruri.kusastro.kyoto-u.ac.jp, 
vsnet-outburst at yahoogroups.com, suuma at yahoogroups.com, 
variable_star_forum at yahoogroups.com, 
vsnet-campaign-dn at ooruri.kusastro.kyoto-u.ac.jp,	vsnet-alert at yahoogroups.com

Astrometry from one 60-second V filtered image at Astrokolkhoz:

PR Her (J2000)
18 08 04.47 +38 46 17.0

Tom Krajci

=============================

On 11/22/2011 6:42 PM, Taichi Kato wrote:
> As informed below, PR Her is undergoing a rare bright outburst!
> The quiescent magnitude is reported to be 21, and this object is
> most likely a WZ Sge-type dwarf nova (known maximum was 14.0p).
> All sorts of observations are encouraged!  Accurate astrometry
> of the outbursting object is also needed.
>
> ===
>
> From: FIDRICH Robert<fidusz at zpok.hu>
> Date: Tue, 22 Nov 2011 20:29:56 +0100
> Subject: [cvnet-outburst] PR Her in bright outburst?
>
> Dear Folks,
>
> Walter Macdonald just alerted us on the #aavso IRC channel, that PR Her
> is in avery bright outburst near 13th mag.
>
> His CCD picture can be found at:
> http://starlightccd.com/temp/002-prher-2x30s.jpg
>
> Is is probably a rare superoutburst?
>
> Clear skies,
>

-- 
-------------------------------------------
Tom Krajci
Cloudcroft, New Mexico
http://picasaweb.google.com/tom.krajci

Center for Backyard Astrophysics (CBA)
https://cbastro.org/ CBA New Mexico

American Association of Variable Star
Observers (AAVSO): KTC http://www.aavso.org/
-------------------------------------------



From jop at astro.columbia.edu  Wed Nov 23 11:08:41 2011
From: jop at astro.columbia.edu (Joe Patterson)
Date: Wed, 23 Nov 2011 11:08:41 -0500
Subject: (cba:news) Fwd: (cba:chat) RXJ0524+42 is mag 17, but large amplitude
In-Reply-To: <4ECD0258.6020109@tularosa.net>
References: <4ECD0258.6020109@tularosa.net>
Message-ID: <4ECD1A89.5040003@astro.columbia.edu>



Hi CBAers,

OK, here's the proof of concept, from Tom.  It's a deep, dark, and 
mysterious star.  We can hope to at least dispel some of the mystery... 
and it does seem to be ripe for CBA attack.

joe

......

RXJ0524+42 is mag 17, but large amplitude.  My C11 did a decent job on
it.  It would be great to see other longitudes covering this object.

-- 
-------------------------------------------
Tom Krajci
Cloudcroft, New Mexico
http://picasaweb.google.com/tom.krajci

Center for Backyard Astrophysics (CBA)
https://cbastro.org/ CBA New Mexico

American Association of Variable Star
Observers (AAVSO): KTC http://www.aavso.org/
-------------------------------------------


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From jop at astro.columbia.edu  Sat Nov 26 05:57:36 2011
From: jop at astro.columbia.edu (Joe Patterson)
Date: Sat, 26 Nov 2011 05:57:36 -0500
Subject: (cba:news) Outburst of VW Hyi
Message-ID: <4ED0C620.7040106@astro.columbia.edu>

Dear CBAers,

Despite the rash of fascinating targets in this month's night skies - 
and in particular the first-in-history eruption of BW Scl - I'm inclined 
to give VW Hyi an emphatic welcome to the CBA menu.  Although it has 
been studied a lot, it has never been thoroughly studied with today's 
"all-telescopes-all-the-time" techniques... and as one of the 
nearest/brightest dwarf novae, it promises to yield a lot of information 
from such close scrutiny.  In particular:
(1) the fascinating but still little-known fine structure of superhumps 
(nw-mW, where n and m are unequal integers);
(2) the details of how power gets shuffled between orbit and superhump 
frequencies;
(3) the possible transient appearance of negative superhumps; and
(4) the precise shape of the long-term O-C.

With very nearly global coverage of the outburst, I bet VW Hyi would 
have something useful to contribute to each of these questions.  And 
that doesn't even count the harvest of unanticipated results... which is 
the usual outcome of *any* scientific experiment!

I imagine that VW Hyi will be an all-night target for you australites... 
which might threaten BW Scl somewhat.  I hope there's enough telescopes 
and overlap of coverage to permit both targets!

joe


Why?  Because it's one of the very brightest of dwarf novae

-------- Original Message --------
Subject: [vsnet-alert 13894] Outburst of VW Hyi
Date: Sat, 26 Nov 2011 11:19:53 +0100
From: Josch Hambsch <hambsch at telenet.be>
To: <vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp>



Dear all,

I have been observing VW Hyi for the past two nights on request and 
observed a rise in magnitude from about 13.5 on Nov. 24/25 to 10.1 on 
Nov. 25/26.
I have taken time series during both nights (the last night is still 
busy to be analysed) and those will be submitted to VSNET and AAVSO.
Please advice whether I should continue time series or only snapshots 
during the coming nights.

Regards,

Josch

http://www.astronomie.be/hambsch



From jop at astro.columbia.edu  Mon Nov 28 07:32:39 2011
From: jop at astro.columbia.edu (Joe Patterson)
Date: Mon, 28 Nov 2011 07:32:39 -0500
Subject: (cba:news) stars for december
Message-ID: <4ED37F67.90009@astro.columbia.edu>

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