From jop at astro.columbia.edu Tue May 6 08:03:59 2008 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 06 May 2008 08:03:59 -0400 Subject: (cba:news) stars for may Message-ID: <4820492F.2080207@astro.columbia.edu> Dear CBAers, The flowers are blooming, the Red Sox are in first place, U Sco is ready for an outburst, the DQ Her ephemerides are under control. Even the fleas are back. It must be a new season... and time for a wholesale change of targets. Barring a dramatic eruption, I'd like to take advantage of the new moon and focus on some pretty faint stars now. In particular: 1. GW Lib. This is still slowly declining, I think, from its 2007 eruption... but is probably about 16.3 now. Manageable in decent weather. It has never been observed in a fresh postoutburst state, and there are a host questions: is there an orbital signature? are the white-dwarf pulsations back? and what about the strange 2.1 hour photometric signal (that still defies explanation)? This is an IDEAL target for southern observers at all longitudes - and as long as possible each night, to distinguish among aliases and to increase resolution. It's also good for ambitious observers in the southern USA (Tom, you know who you are), since that's a critical longitude. 2. SDSS1238-03 (Vir). No eruption, but we had good luck tracking the 8-hr variation in 2006, and it too remains a mysterious beast since Porb is known to be very short. For southerners, this mostly conflicts with GW Lib, so take one and stick with it. It's a little fainter, about 17.5... but the variations are likely bigger. Good for all latitudes, though! 3. Oph (1730-05). A favorite DQ Her star newly arrived in the sky. V=16, can be a quasi-backup target. 4. SDSS1502+33 (Boo). A deeply eclipsing star V=17.6. See if you can get it; a faint-limit test for northern observers. 5. SDSS0804+51 (Lyn). Still available as an evening target for northerners. Need some more pulse timings. 6. Finally, WX Cen (1312-63). Bright-star backup for southerners. We need another season to complete a period study. Pretty nice photometric wave. Meeting notes: * the Big Bear meeting is coming up over Memorial Day weekend. I won't be there but there's usually a CBA contingent (Jerry Foote and Bob Koff are regulars). * I will attend the early-January meeting in Hawaii, and hope to see some of you. * And next year is an AAVSO meeting which I'm likely to declare as a CBA meeting also. See AAVSO site for details. *Also, Tonny and Bart, could you give a report on the BAA-AAVSO meeting in April? Happy observing! joe From jop at astro.columbia.edu Fri May 16 20:22:49 2008 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 16 May 2008 20:22:49 -0400 Subject: (cba:news) CR Boo erupts... Message-ID: <482E2559.7060707@astro.columbia.edu> Dear CBAers, It seems very likely that CR Boo has finally jumped into superoutburst. I got a little impatient last month and called off the coverage... but it's still well placed, still equatorial, and still bright. So I think it deserves the absolute highest priority whenever it's up in the sky - for southern observers as well as northern. We've covered CR Boo before, but never *really* well, and it would be fascinating to know if its superhumps have the same intricate fine structure AM CVn is famous for. We can do that - a week of intense coverage will do the job! As for current targets, GW Lib is being well covered by Berto and Bob Rea... and it's flashing that mysterious 2.1 hr wave that no one understands. Definitely worth tracking. But for WX Cen, I think we can call off the coverage. We have several nice eclipse timings, which suffices for the year. BTW the Sky and Tel article on the Cassiopeia transient (Halloween 2006) finally come out in the July issue. It got delayed by some editor job-jumping... but looks pretty good now. Tom Krajci and Bob Koff are the "photometry heroes"... which they richly deserve! Find your way to Bootes and let 'er rip! joe From jop at astro.columbia.edu Fri May 16 22:13:19 2008 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 16 May 2008 22:13:19 -0400 Subject: (cba:news) [Fwd: USCO2009 Collaboration overview] Message-ID: <482E3F3F.9090007@astro.columbia.edu> Dear CBAers, Here's the latest info concerning Brad Schaefer's attempt to cover the next U Sco outburst. Nothing to do till it outbursts, but it's nice to be ready. The most important photometry is likely to be in the first 2 days, since it's *extremely* fast. joe -------- Original Message -------- Subject: USCO2009 Collaboration overview Date: Fri, 16 May 2008 14:33:36 -0500 (CDT) From: Brad Schaefer To: Andrew Collazzi , Arne Henden , Ashley Pagnota , Ben Sugerman , Bill Sparks , Brad Schaefer , Brian Warner , "Christopher L. Gerardy" , Dan Green , Dan Reichart , David Buckley , David K Lynch , Eric Schlegel , Fred Ringwald , Fred Walter , "Howard E. Bond" , Howie Marion , Joe Patterson , Jonathan Kemp , Matthew Templeton , Patrick Woudt , Rob Robinson Hi; The recurrent nova U Sco will soon be erupting, with the eruption being expected next spring, but it could go up any night now (2009.3+-1.0; Schaefer 2005, ApJLett, 621, L53). Here is an overview of current plans and capabilities for the USCO2009 Collaboration. We have a grand set of capabilities that cover everything. This email is so we all know the bigger picture. Here is a summary of the capabilities that we already have in place: PHOTOMETRY SPECTROSCOPY POLARIMETRY Pre-eruption ROTSE 3a, 3b, 3c, 3d Pre-eruption AAVSO Pre-eruption CTIO 1.3m IR CTIO 1.3m IRTF Optical CTIO 1.3m CTIO 1.5m PROMPT Optical CBA (fast time-series) UV Swift Swift X-ray Swift Swift In all, we'll get great photometry and spectra all the way from 10 keV to 3 microns (with only a gap in the EUV) and with time resolutions from hourly to nightly. If circumstances are good, this eruption of U Sco will be by far the best observed nova event ever. And this is all because we know *which* star will have a nova eruption and an approximate time for that eruption. For the pre-eruption time interval, we have the four ROTSE telescopes worldwide (Australia, Texas, Namibia, and Turkey) each checking once an hour. For example, in the last week (with average cloudiness and such), we are getting an average of 17 images per day well-spaced around the clock with most images just barely showing U Sco in quiescence. We also have the CTIO 1.3m getting accurate photometry every 5 days. But these images are not being automatically checked, so the real discovery will almost certainly come from AAVSO observers. Notification that U Sco is up will go to AAVSO Headquarters (monitored roughly 24/7) or possibly the CBAT (with Dan Green and colleagues on fast checking). The full instructions for starting all our observing plans will be handled by myself and/or Ashley Pagnotta (or AAVSO Headquarters if we cannot be reached). I have attached to this email the instructions that we will be operating with. (Non-public phone numbers and such have been partially 'X'd out as appropriate.) The purpose of passing this along to everyone is to allow full knowledge of the bigger picture. Also, it is important that you look over the instructions relating to yourself and alert me to any changes or errors. I have also attached a WORD document that contains a set of finder charts for U Sco, with many specific comparison stars identified and BVRIJHK magnitudes for these. We had decided against an HST proposal as the calculations suggested that the shell would be too faint, and since a shallow image from 1999 showed no shell. We think that Chandra and GALEX are not a good data source due to its slowness for reaction and the small amount of time that anyone could get. (Swift is just so perfect for us.) We realize that there is no need to propose for big telescope time, as U Sco will be too bright, and as high spectral resolution is not needed due to the >5000 km/s expansion velocities smearing out all narrow features. A capability missing here is any radio measures, but for this I do not know either what to expect nor any reason to look in radio. Perhaps the joint experience of people on this email can suggest a good science expectation and the best way to proceed. Another need is that we have little redundancy, so clouds at CTIO or elsewhere could substantially hurt the coverage (especially in the first week). So I would welcome any further collaborators for USCO2009. In particular, I can imagine that MONET (a remotely controlled {possibly automated} 1.2m pair of telescopes in Texas and South Africa) and the CV group in South Africa would both relish the opportunity. As for the politics of the USCO2009 collaboration, there are only the normal imperatives. People are free to publish their data as they will, with whatever appropriate authors on the author list. We will have one-or-more omnibus papers for which I expect that all our data will be freely included. In the end, for a well-timed U Sco eruption date, we will have a WOW! set of data. Cheers, Brad -------------- next part -------------- A non-text attachment was scrubbed... Name: USCO2009plans.doc Type: application/msword Size: 160256 bytes Desc: not available URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: UScoFinderCharts.doc Type: application/msword Size: 639488 bytes Desc: not available URL: From jop at astro.columbia.edu Tue May 27 23:12:25 2008 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 27 May 2008 23:12:25 -0400 Subject: (cba:news) GW Lib and MV Lyr Message-ID: <483CCD99.7080704@astro.columbia.edu> Dear CBAers, I've caught up with the analysis of the CR Boo and GW Lib data. CR Boo is up to its usual (well, common anyway) hijinks, ramping up and down on a timescale of about a day. The high-state "superoutbursts" are just too short to permit very sensitive periodic-signal study. It'll be a good study - sixty days worth - but it's time to end it. The best southern object now is definitely GW Lib, which is flashing a powerful 2.1 hour photometric wave. Perfectly placed now for a multi-longitude study! Likewise for MV Lyr, usually around 12.7 or so, and just recently dropped 2 mag or more. For years we've wanted to get orbital light curves just after a transition to a faint state. Now's the chance! joe