From jop at astro.columbia.edu Thu Sep 8 10:11:46 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 8 Sep 2005 10:11:46 -0400 (EDT) Subject: (cba:news) september stars Message-ID: Dear CBAers, Many changes in the offing this month. Not the least of which is - I get back to work! First classes this week. I suppose summer should in principle be the time when we get most of our research done... and I faintly recall this being so a long time ago. But no more. I think just the discipline of regularly going to an office and plopping down at a desk. The AE Aqr campaign is finished, so any data you haven't submitted would be nice to see now. (Actual publication is, as usual, a year or so away - but as the analysis grinds through, it would be good to have a stable set of original data.) Ditto for V1082 Sgr. Jennie and Berto worked hard on this one, but it's too early to say what's in it - and too late in the season to keep it going. Four other stars need to be scuttled on grounds of insufficient interest: MN Dra, V1327 Aql, V1006 Cyg, V632 Cyg. Like unpopular politicians and movies, poor ratings sink stars on our list, even if nothing else does. We carried out decent - though not excellent - campaigns on IX Dra (mostly Lew Cook) and V1494 Aql (mostly Bob Rea). These stars will be obvious winners in a future year - presumably next - when we can get very dense global coverage. For the latter we can derive a stable long-term ephemeris, once we tie all the years together. They're also sinking too low in the west - so away eith 'em! A really rewarding star on the present menu is HS1813+61 ("Dra" in the Downes catalogue). Dave Messier has been taking advantage of the post-Katrina spell of beautiful weather in the northeast U.S. to get long runs on this star. It has a beautiful negative superhump at ~3.4 hrs, and probably a "disk wobble" period at ~3 d. Another week or two of coverage - say till the next bright moon - would really nail this one to the wall. Borealanders, fire away! VZ Scl looks very promising in the south, too. Not too much yet - mostly from Alon Retter/Alex Liu - but the star shows deep eclipses and large orbital or quasiorbital humps. Right up our alley! Definitely the prime target for good nights now in the south. EC 21178-5417 ("Ind" in the Downes catalogue) is a good secondary target - about 13.5 versus 15.7 for VZ Scl - since it's bright and can survive more moonlight and clouds. Another deep eclipser. The world doesn't know too much about either of these stars, although VZ Scl has been squatting in CV catalogues for many decades. New northern targets. "Cep 1" = GD 552. We have a long-term spectroscopy-photometry-astrometry-alchemy campaign just about to wrap up on this fascinating star, possibly the oldest of all CVs. One more season of photometric coverage will bring the concoction to a perfect state. Nominally a "noneruptive" CV, though you'll notice some burps and hiccoughs going on in the light curve. About 16.5, needs a decent night. HS 2331+3905 = "And". Same general story, though the star's a bit brighter at 15.6. Many fascinating periods in its light curve! LS Peg. At V=12-12.5, this is a great target for nights of lesser quality. We did a great campaign in fall 02, and want to update the periods and check for long-term stability. Another season will finish the job. BTW at +14 degrees dec, this is plenty suitable for southern observers. And FO Aqr and AO Psc remain good backup targets - bright and not needing (as most of our targets do) long coverage! Joe From jop at astro.columbia.edu Fri Sep 23 07:25:25 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 23 Sep 2005 07:25:25 -0400 (EDT) Subject: (cba:news) new targets Message-ID: Dear CBAers, Full message coming tomorrow. But two major targets should be retired: HS1813+61 (too late in the season!) and EC2117-54 ("Ind"; great orbital signal but good upper limit on superhumps). The best northern targets now are Cep1 (GD552) and HS 2331+39 (And) -- or LS Peg if you can't quite handle these somewhat tough targets (V~16.5). In the south, I vote for BW Scl - another tough one at 16.5. Or LS Peg (only mildly northern at +14 deg), which is plenty bright and could really profit from the worldwide coverage. joe From jop at astro.columbia.edu Thu Sep 29 23:42:32 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 29 Sep 2005 23:42:32 -0400 (EDT) Subject: (cba:news) stars for october Message-ID: Dear CBAers, The LS Peg campaign is ready for wrap-up now. The star displayed a handsome negative superhump throughout, with coverage dense enough to enable sensitive search for some of the lesser-known effects (especially the precession period itself). It's not going to get any better, so it's time to quit. Two other prime targets du jour are Cep 1 and HS2339+30 ("And"). These are not eliciting much attention! I realize they're tough - around 16.5 - but the Moon's outa the way and these stars, likely to be among the oldest of cataclysmic binaries, will repay handsomely in terms of the science reaped (even if the light curve's no thing of beauty). Two new (relatively) bright northern targets. The first is LD 317 ("And"), a rewarding 14.5 mag star which we started last year and seemed to find 5 hr and 25 minute modulations. These demand more study! The second is LQ Peg, of similar brightness and unknown period. Our past efforts on LQ Peg have been meager and unsuccessful - and so, for that matter, has everyone else's. And in the south... We had quit on RZ Gru... but then the star started to dive down to a low state, and that enormously boosts its priority (because it's rare that we get to observe these things with advance notice). So RZ Gru, presently hanging near 14th magnitude, is now a very good target for long time-series coverage. As is BW Scl. In that one (about 16.5-17) we're mainly interested in the orbital signal, although anything else would be a bonus - and an outburst would be gold (none recorded in history, although it's very likely to be a dwarf nova). So there's the new menu. Happy observing! Beautiful fall weather has finally struck in the northeast US - I hope it's as fine where you are. joe