From jop at astro.columbia.edu Sun Nov 6 03:57:23 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 6 Nov 2005 03:57:23 -0500 (EST) Subject: (cba:news) ld317, exit left Message-ID: Dear CBAers, I'm about halfway through the analysis of this year's LD317 data. The campaign looks promising, but the runs are getting a bit shorter now... and I reckon it's time to put our efforts elsewhere. Let's take advantage of the dark skies now to squeeze out some data on ES Cet (0206-09) and "And" (HS2331+39)! These stars are 16.5-17, but of great astrophysical interest since they represent very late stages of binary evolution. Both should be evolving under the control of gravitational radiation, and tracking their period changes is one of the best - perhaps the best - ways to constrain the effect of GR. In the south, BW Scl is of equal interest, amd for the same reason. And comparably faint. When Olde Whiteface rolls back into the sky in 7-8 days, we'll probably launch the major mid-November campaign on TT Ari - which some observers have jumped on already. A few southerners may have tried to measure EX Hya - now in outburst. This is awfully interesting, but the sky position is so horrible that I'm reluctant to recommend it. Maybe with a deep red filter and a pile of fortitude...? BTW I've decided to call a general CBA meeting at the next Big Bear photometry conference (Society of Astronomical Sciences, nee IAPPP). This is in late May in southern California. We've done several of these before, at AAS and ASP meetings... and it's time to do another. Nice venue too... I used to run my summer camps there in the 1970s, in fact at the identical site later (and now) used by the Riverside ATM conference. I probably will have some observing time lined up on Kitt Peak (near Tucson AZ) right around then too, so we can perhaps pack in some actual science too, and some observatory tourism. More later! joe From jop at astro.columbia.edu Wed Nov 16 05:30:09 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 16 Nov 2005 05:30:09 -0500 (EST) Subject: (cba:news) TT Ari and two sure winners In-Reply-To: Message-ID: Dear Tom and CBAers, TT Ari is often a very good target this time of year - being so bright, tantalizing us with a sheaf of periods, and more or less accessible to both hemispheres. Tom has obtained a few consecutive nights at very high time resolution, and Bill Allen and Jennie McCormick have also covered it from NZ. There was an early report of the star's fading, a rare event of much interest in this type of star ("VY Scl star"). But then it popped back up again to ~10.6... does it deserve to stay on our menu? Well, I looked at this year's coverage. Same old TT Ari, seducing with that annoying 20 minute QPO... and largely (or perhaps altogether) missing any trace of superhump. We know that novalikes turn off their superhump machines episodically, so this is not of substantial interest by itself. In some future golden age, we - or someone - may actually get enough data to show how the superhump machine turns on/off... but at present this is far beyond us. The 20 minute signal may yield to tenacious observers a bit earlier; I think it will, but I also think we're not quite ready to wage that big a war on it. So my response to Tom's question is: (1) As far as we know, time resolution beyond 30-60 s is not needed on TT Ari; (2) the star should be mostly dropped from our menu (mainly for failing to yield a superhump signal); and (3) it remains of interest for very bright-moon conditions, when some of our hotshot targets have trouble surviving the background light. The two stars I want to commend with maximal enthusiasm right now are BW Scl and HS2331+39 (one of the "And" stars in the Downes et al the catalog). Each is ~16.5, with very strong signals at 35.5 cycles/day - basically twice the orbital frequency. And each has a raft of other periods it flashes at us. These are poster-child stars for period finding: the raw light curves (in smallscope data) are so ugly and the period-search results are so beautiful! And they're sittin' up there in the evening sky symmetrically placed for N and S observers... these stars are just one CBA observing season away from the cataclysmic-variable Hall of Fame! And a little later in the night for N observers, FS Aur rolls back into view. As some of you know, this star continues to baffle with its inscrutable 3.5 hr photometric signal of unknown origin. Let's grab it early in the season and not let it go till it vanishes in those March sunsets! BTW we have now established that we will have a CBA meeting coincident with the SocAstroSoc (formerly IAPPP) meeting in Big Bear, CA during May 24-26, 2006. Since they'll have 100+ people and we'll have maybe 10-12, we'll just be a small part of their meeting - so you should just register for their meeting. In the next 2-3 weeks, some more information will be coming re this. joe From jop at astro.columbia.edu Mon Nov 21 05:00:31 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 21 Nov 2005 05:00:31 -0500 (EST) Subject: (cba:news) ATel 658 (fwd) Message-ID: This eruptive star may, or may not, be one of our boys... but it's likely to be pretty interesting no matter what. I recommend it for N observers - much as I hate to steer attention away from the fascinating HS2331+39! joe ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ The Astronomer's Telegram http://www.astronomerstelegram.org ------------------------------------------------------------------------------ Posted: Thu Nov 17 01:30:00 EST 2005 -- Sun Nov 20 01:30:01 EST 2005 ============================================================================== ATEL #658 ATEL #658 Title: Dwarf Nova TSS J022216.4+412260 Author: R. Quimby, M. Sellers, P. Mondol (U. Texas) and The Nearby Supernova Factory: P. Antilogus, S. Gilles, R. Pain, R. Pereira (Laboratoire de Physique Nucleaire et de Haute Energies de Paris), N. Blanc, S. Bongard, Y. Copin, E. Gangler, L. Sauge, G. Smadja (Institut de Physique Nucleaire de Lyon), G. Aldering, S. Bailey, D. Kocevski, B. C. Lee, S. Loken, P. Nugent, S. Perlmutter, R. Scalzo, R. C. Thomas, L. Wang, B. A. Weaver (Lawrence Berkeley National Laboratory, Berkeley, CA), C. Bonnaud, E. Pecontal (Centre de Recherche Astronomique de Lyon), R. Kessler (Kavli Institute for Cosmological Physics, Chicago, IL), C. Baltay, D. Rabinowitz, A. Bauer (Yale) Queries: quimby at astro.as.utexas.edu Posted: 19 Nov 2005; 19:03 UT Subjects: Optical, Cataclysmic Variables, Transients We report the discovery of an optical transient using unfiltered CCD images taken on November 16.1 UT (about 15.5 mag) and November 17.1 (also about 15.5 mag) using the 0.45m ROTSE-IIIb telescope at the McDonald Observatory. The object is located at RA = 02h22m16.4s DEC = +41o22'59.9" (J2000; uncertainty +/- 0.5"). TSS J022216.4+412260 was not detected in ROTSE-IIIb data from November 15.1 UT (limiting mag about 16.5). The Nearby Supernova Factory adds that a spectrum (range 320-1000 nm) of TSS J022216.4+412260 obtained November 18.6 UT with the Supernova Integral Field Spectrograph on the University of Hawaii 2.2-meter telescope, shows it to be a dwarf nova in outburst. The spectra reveal a blue continuum with prominent H-alpha and HeII 4686 emission lines. ------------------------------------------------------------------------------ Password Certification: Robert Quimby (quimby at astro.as.utexas.edu) http://www.astronomerstelegram.org/?read=658 ============================================================================== Your keywords: Radio, Millimeter, Sub-Millimeter, Far-Infra-Red, Infra-Red, Optical, Ultra-Violet, X-ray, Gamma Ray, >GeV, Request for Observations, A Comment, AGN, Asteroids, Binaries, Black Holes, Comets, Cosmic Rays, Cataclysmic Variables, Globular Clusters, Gamma-Ray Bursts, Meteors, Microlensing Events, Neutron Stars, Novae, Planets, Planets (minor), Pulsars, Quasars, Soft Gamma-ray Repeaters, Solar System Objects, The Sun, Supernovae, Supernova Remnants, Transients, Variables, Stars ============================================================================== This is an automatically-generated notice. If you'd like to be removed from the mailing list, please visit the The Astronomer's Telegram at http://www.astronomerstelegram.org . From jop at astro.columbia.edu Tue Nov 22 08:18:36 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 22 Nov 2005 08:18:36 -0500 (EST) Subject: (cba:news) DV Dra extremely rare outburst (fwd) Message-ID: Dear CBAers, Here's Patrick Schmeer's announcement of a DV Dra outburst. Normally this would be too far over in the eastern sky for us... but with European *and* American coverage, we should be able to spot superhumps if they're there. So it's a good target for the early evening - much as I hate to divert attention from HS2331+39. Hard to argue with the first eruption in 21 years. joe **************************************************** Unfiltered CCD observations by P. Schmeer, Bischmisheim, Germany: DRADV 20051115.065 <175CR Scp DRADV 20051117.067 <180CR Scp DRADV 20051118.064 <172CR Scp DRADV 20051119.064 <180CR Scp DRADV 20051122.062 151CR Scp Instrument: University of Iowa, Rigel Telescope (0.37-m Cassegrain) Sequence: Henden and Sumner (R magnitudes derived from V and B-V) On the outburst image I measured the following position: R.A. 18h17m23.07s Decl. +50o48'17.7" (J2000.0) The only previously recorded outburst (a supermaximum) of this UGWZ candidate was observed on 1984 June 1.9 UT at mpg= 15.0 (IBVS 3626). Time-resolved photometry is very urgently required. Regards, Patrick From jop at astro.columbia.edu Tue Nov 22 17:22:14 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 22 Nov 2005 17:22:14 -0500 (EST) Subject: (cba:news) DV Dra Message-ID: So based on Tonny's report from Europe tonight, I'd say that Dame Fortune is smiling broadly on DV Dra right now. Slew that telescope around to the northwest, and fire away! And call all your friends from points west! joe