From jop at astro.columbia.edu Sat Jun 1 14:07:24 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Sat, 1 Jun 2002 14:07:24 -0400 (EDT) Subject: (cba:news) V803 Cen erupts Message-ID: Dear CBAers, Berto Monard and Rod Stubbings caught V803 Cen rising to a second supermax on May 29. That's the event we (well, our southern branch anyway) have been waiting for. We've followed the evolution for 75 days since the last super, and now just want to end the campaign with a week or so of rousingly dense time series - a final flourish of trumpets as the curtain descends. So let's boost that one up to mega-star status. The coverage of RX1643+34 was just great, and I've nearly finished writing up the paper (about another month to clean it up though). Let me know if you'd like to receive some of the spliced data near your own observations. No need to observe that star again unless it changes luminosity state. V849 Her kind of washed out. Dave Skillman's data is pretty flat, and we're not patient enough to wait around for it to get interesting. Cast it out. But V795 Her has returned with its powerful superhumps, and this is definitely the prime northern target for June. At magnitude 12.7, good for all and very peachy for small and middling scopes. Then there's V2051 Oph, still fairly bright and still the best late target for southern scopes. Coverage of this long outburst is really making it the WZ Sge of the south, although it doesn't have the fancy publicity of the latter. Keep up that faithful and wonderful coverage! I dunno what to make of V4641 Sgr. For our particular telescopes and observing styles, I'm inclined to give it quite a bit lower weight than V803 Cen and V2051 Oph in this month's sky. I might be wrong, of course. joe From jop at astro.columbia.edu Mon Jun 3 18:25:39 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 3 Jun 2002 18:25:39 -0400 (EDT) Subject: (cba:news) fireworks in centaurus Message-ID: Dear CBAers, I think it's time to put V359 Cen on the program. It may be a long time before it erupts to supermax - so let's strike when the iron is hot. This competes with V803 Cen, which is now pulsing mightily with superhumps (which we caught beautifully on the rise in Greg Bolt's and Neil Butterworth's data). So let 'em compete, I guess. Much as I like to keep up the pressure on one target, they're both quite important. Let 'em duke it out in the evening sky! joe From jop at astro.columbia.edu Wed Jun 12 16:18:36 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 12 Jun 2002 16:18:36 -0400 (EDT) Subject: (cba:news) stars new and old Message-ID: Dear CBAers, Well the WZ Sge opus finally came out, on the PASP "early release" website... plus the papers on HT Cam and RX2329+06. They let me have my cartoons and classical allusions, so I'm happy. You can get there via the "links" on the cba website. V803 Cen came off its supermax and is now doing its cycling thing. So we've gone beyond a full cycle, and can quit for the year! Time to retire the old dame. Likewise for V2051 Oph - although it's staying decently bright, the superhumps have gone and the rate of information return has declined a lot. So let's retire 'em both! Meanwhile, it's high time to take up the cause of V442 Oph. Long runs, densely spaced at all the terrestrial longitudes you can dream up (including you naughty North Americans out there) - that's what we want to properly subdue V442. In the north, V795 Her is still an attractive target, but I warmly commend LX Ser and V1494 Aql as alternatives. V795 Her has a brilliant superhump and is a seductively bright star, but the signal is pretty stable and there is no aliasing... so it may be basically "steady as she goes" for the rest of the season (but who knows, maybe not). LX Ser and V1494 Aql would be more valorous targets right now. joe From jop at astro.columbia.edu Fri Jun 14 08:40:40 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 14 Jun 2002 08:40:40 -0400 (EDT) Subject: (cba:news) KL Dra! Message-ID: Dear CBAers, Just wanted to chip in my enthusiasm for this target. We've had a devil time getting it to erupt - only Matt seems to have the touch. Even a few nights of photometry, well-timed and all night long, would give that precise period we desire so much! Don't forget about that contaminating galaxy, for which you might want to make some special arrangements after KL Dra fades a bit. joe ---------- Forwarded message ---------- Date: Thu, 13 Jun 2002 17:01:20 -0400 (EDT) From: Matt Wood To: Joe Patterson Cc: cba-news at cbastro.org Subject: (cba:news) KL Dra Joe et al.: A student and I obtained some data from the SARA Observatory (0.9-m) at Kitt Peak 2 nights ago on KL Dra (2002-06-12 UT). Looks like we caught it just starting to superhump. If any CBA'ers have large telescopes -- large enough to reach something roughly 15.5 to 16th magnitude when in high state -- and are so inclined, more data would be wonderful. We've got a paper in press in Monthly Notices, which you can find online at www.astro.fit.edu/wood/mnr_kldra.pdf I put the data from 020612UT in www.astro.fit.edu/wood/sara152.pdf The top panel is the raw counts in ADUs (gain is 6.1 if you want photons detected). Panel 2 is the 4 comp stars, panel 3 is the target divided by the comp stars (this is the differential photometry curve), and panel 4 is the sky (beautiful photometric night). KL Dra is the most recently discovered AM CVn (helium superhumper), and appears to be a near clone of CR Boo, with a period of 25.5 minutes. Cheers, Matt -- Matt A. Wood, Associate Professor Email: wood at wd.astro.fit.edu SARA NSF-REU Site Program Director Tel: (321) 674-7207 Dept. of Physics and Space Sciences Fax: (321) 674-7482 Florida Institute of Technology WWW: www.astro.fit.edu/wood Melbourne, FL 32901-6975, USA SARA-WWW: www.astro.fit.edu/sara From jop at astro.columbia.edu Mon Jun 24 16:17:52 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 24 Jun 2002 16:17:52 -0400 (EDT) Subject: (cba:news) V442 Oph, and other notables Message-ID: Dear CBAers, The campaign on V442 Oph is about ten days old now. The star is flashing a beautiful negative superhump at about 2.9 hours. But although we have some coverage from three widely separated longitudes (South Africa, AU-NZ, and UT/AZ), we don't have really long coverage from any of the sites. So the data are not yet suitable for a calibrated merge - which requires some simultaneity of observation. We should keep going on this star for a few more weeks, and I hope that you can get long observing runs since that's really the key to continuous and calibrated coverage. V795 Her, time to retire. Just tweaking down the error bars from here on. Although I've retired RX1643, more coverage of this star would be quite useful. It has the *strongest* quasi-periodic oscillation (QPO) of all the SW Sexers, and another flurry of observation could possibly pin down the stable signal that underlies (if any). It's also perfectly placed for northern observers right now. I give V442 Oph higher priority, but it's hard to ignore 50 degrees of declination difference. Two other excellent stars are swinging into view, and nicely perched near the equator: V1494 Aql and V603 Aql. These will definitely be our great campaign stars for July... and it's time to start now. Lew Cook's season-starting run on V1494 Aql shows lovely eclipses. Make friends with the field, and let 'er rip. joe From jop at astro.columbia.edu Sun Jun 30 12:15:13 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 30 Jun 2002 12:15:13 -0400 (EDT) Subject: (cba:news) new month, new targets! Message-ID: Dear CBAers, The arrival of a paycheck reminds me of a new month approaching. (I'm kind of a julian-date guy.) Time for a revolution in CBA targets. V877 Ara is out of outburst, LX Ser is a little out of season, and KL Dra is out of unconfused photons. All decent reasons to drop these stars from our list. We now have precision ephemerides for V795 Her and RX1643+34. These were superb campaigns. Just writing the paper up... couldn't have done any better! What a pleasure that was, and is. But no need to continue these campaigns. V442 Oph needs another week or two of coverage, especially from the south. Turns out that Jerry Foote, I assume dodging forest fires, has been getting very regular observations. They're necessarily short from the north, so we're still kinda sparse on long runs (despite one 10-hour run from Berto). So keep the faith. The northern object I REALLY want to promote now is V533 Her. It's perfectly placed, about 14.5 mag, and likely has a shiny new superhump. It does have a star of equal brightness 10" away, so some of you will need to fuss over that circumstance. Short exposures might help a lot. Also, there's a small-amplitude signal at 63 seconds in this star. Those of you with bigger scopes might want to try resolving it - needs a total cycle time (exposure plus readout) of less than 20 seconds. The main interest is the superhumps that are likely to be present near 3.5 hours, and a 10-minute quasi-periodic signal (of unknown origin). Cap'n Bob and Lew Cook have started us up on V1494 Aql. That takes care of an early-season point. We can now afford to wait a while before a very intense campaign. But both V1494 Aql and V603 Aql are pretty damn good targets right now, so if either of them suits you (they're pretty bright), then let 'er rip! joe