From jop at astro.columbia.edu Thu Dec 4 17:23:47 2003 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 4 Dec 2003 17:23:47 -0500 (EST) Subject: (cba:news) ty vul and fy per, mainly Message-ID: Dear CBAers, Dave Messier found freshly emergent superhumps in TY Vul last night - checking in at 0.080+-0.002 days. This is basically a virgin dwarf nova (to the world that is) and it would be awfully nice to nail down the period to four or so significant figures. I think we'll need some European or Uzbek help on that one! Or at least Californian. Sorry for the bad seasonal timing. The moon's getting pretty bright, and it might be a good time to get a few nights on FY Per. This is a very bright star, and the light modulation is pretty weak (just 0.05 mag or so). But it occurs at a very weird period, about 1.5 hours compared to a 6.2 hour orbital period. We still don't really understand what makes a variation like this - and never will unless we get some good coverage of it. Try to get long runs, and cluster 'em together as tight as you can. The other good northern campaign star is FS Aur. The bright moon might clobber it, though - best to do FY Per until the Moon's outa the way. I think we should RETIRE Cam = RX0625+73 - we have *great* coverage of it (from Tom, Tonny, and Dave Messier) over fifty days, so we can definitely take a rest... possibly for the season. HS0455+83 is worth continuing, but will end soon as its campaign is approaching 50 days also. In the south, the big stars are TV Col and AH Men, and these will remain top-priority for at least another month. The X-ray observation of TV Col is continuing - so keep the faith! joe From jop at astro.columbia.edu Fri Dec 5 04:57:50 2003 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 5 Dec 2003 04:57:50 -0500 (EST) Subject: (cba:news) UZ Boo erupting? Message-ID: Dear CBAers, Pavel Dubovsky just reported UZ Boo at V=12.8... which, if true, probably signifies a superoutburst. This one is of very great interest, since the eruptions are so rare (ten years or so). Worth a valiant effort to verify, and take a time series, in those frosty predawn hours! Thanks to Arne for reminding of TY Vul's bright neighbor star. You can easily see it on the Downes et al. chart. It's too close for most of you to exclude, so you'll need to include it cleanly (fairly large aperture). About 2 mag down from eruption, it'll basically put us outa business... but decent coverage over the next week might well give us a good superhump period, which is likely to be the main result under these compromised conditions. First Eastern USA snowstorm of the season due to arrive today. joe From jop at astro.columbia.edu Wed Dec 10 06:23:59 2003 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 10 Dec 2003 06:23:59 -0500 (EST) Subject: (cba:news) UZ Boo Message-ID: UZ Boo in superoutburst - at last. December is nasty for Bootis... but it's likely to be a 10 year wait for the next one. So let's go, folks! We should be able to nail the daily alias with observations from Europe and the USA. This one ROCKETS to the top of the priority list! joe From jop at astro.columbia.edu Wed Dec 17 18:00:56 2003 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 17 Dec 2003 18:00:56 -0500 (EST) Subject: (cba:news) Cameras and stars Message-ID: Dear CBAers, Got a question for the community. Bill Allen recently acquired an ST-9 (replacing his old ST-6), and his Munipac image reduction software does not recognize the ST-9 images. Anyone know what to do? Bill's address is whallen at xtra.co.nz. Except for Tonny, no one's rushing in with UZ Boo observations. I understand why - it's really pretty dreadfully placed in the sky, especially considering the extra hardships of early morning observing in December. But the next opportunity won't come for about a decade... so see if you can find the mettle for it. We're starting to get some data on it from AZ. Some changes in targets. In the south, it's TV Col and AH Men. In the north, DELETE TY Vul (faded) and ADD XZ Eri (in superoutburst - actually, that's a fine southern target too!). DELETE FY Per - I really mean that target for bright-moon conditions, so put it on pause. FS Aur, AO Psc, FO Aqr, V405 Aur are good choices. DW Cnc, a real premium star from last winter, is now back for a repeat run - a great choice in the midnight and morning sky. More in a coupla days. I'm staring at 110 exams to grade. joe From jop at astro.columbia.edu Sun Dec 21 21:45:59 2003 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 21 Dec 2003 21:45:59 -0500 (EST) Subject: (cba:news) sdss0137-09 and TV Col Message-ID: Dear CBAers, Some news about campaigns. Let's ring down the curtain on TV Col. The campaign has gone very well, with substantially equal contributions from Bob Rea, Berto, Greg Bolt, and MDM (AZ). The good spread in geography has specified the periodic content pretty well. However, what shows up is basically the PURE orbital period - over a 22-night observing run. No negative superhump, no nodal signal. That's pretty much it - all we get by extending it is just slightly higher precision. So let's call it a year. Some of you have heard about a superoutburst found by Pretorius and Warner of SDSS0137-09 just last night. We just started observing it in AZ, and it seems to be humping away at large amplitude (and bright). With such a good sky position, I hope CBAers at all corners of the Earth can train their firepower on this one. The reported period is near 79 minutes, a pretty interesting domain! The correct position is 01 37 01.06 -09 12 34.9 (J2000). There's a slight misprint in Brian's positional name. You can find the star and chart in the Downes CV catalogue. So, for southern observers, I recommend 0137-09 and AH Men (which has been spitting out great light curves, courtesy of Bill Allen). For northern observers, here's a good selection: 0137-09, fs aur, dw cnc, and uz boo. In order of increasing RA. We're also pow'f'l interested in pulse timings of Dec-Jan DQ Her stars: AO Psc, FO Aqr, V405 Aur, BG CMi, HT Cam. Individual 2-hour-long observations will do the trick! I sure hope we can get some NZ-AU observations of the new superhumping dwarf nova! joe From jop at astro.columbia.edu Tue Dec 23 10:50:02 2003 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 23 Dec 2003 10:50:02 -0500 (EST) Subject: (cba:news) well, that was fast... Message-ID: I worried about the cycle count for sdss0137-09, since the unfavorable sky position means no one can get long runs on it. But in the first day and a half. we have excellent runs from South Africa (Pretorius, Warner), Australia (Bolt) and AZ (Armstrong, Halpern, Katz). So the alias demon is demon is beaten (Psh =81.6+-0.3 min), and the superhumps are really impressive - smooth as a baby's bottom, and of very large amplitude. Time to settle in for the long haul on this shiny new dwarf nova! Other targets unchanged. Bill Allen and Ton Richards are working on AH Men - I hope that others can join the campaign on this very rewarding star. joe