From jop at astro.columbia.edu Wed Apr 3 11:15:44 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 3 Apr 2002 11:15:44 -0500 (EST) Subject: (cba:news) RX J1155.4-5641 superoutburst Message-ID: Dear (southern) CBAers, Berto Monard has confirmed powerful superhumps at P=0.0622(2) d in this new SU UMa star. It's a bright son-of-a-gun, a perfect CBA target. So much as I hate to direct you away from V803 Cen, I have to admit that this is a better choice right now... since V803 Cen has come down from its super and is in its cycling state right now. Jonathan has put up a chart. Nasty field. There oughta be a law. If you can possibly do both stars, do 'em! Here's Berto's visual detection: Visual observations of 30 March and 1 April 2002 observer: Berto Monard MLF, Pretoria, South Africa location: -25 54' 48", 2826' 44"E instrument: 32cm /f4.8 Newtonian conditions: clear RXJ1155.4-5641 020330.768 122 MLF outburst RXJ1155.4-5641 020401.740 109 MLF superoutburst joe From jop at astro.columbia.edu Sun Apr 7 13:47:46 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 7 Apr 2002 13:47:46 -0400 (EDT) Subject: (cba:news) stars for mid-april Message-ID: Dear CBAers, As most of you know, Tonny just discovered superhumps in V589 Her, a little-studied dwarf nova. The period is interestingly long, and the star has never before popped up on our radar screens. Let's put this object as number one priority as soon as it rises. It's in the Downes catalog. Just for the record, 2000 coords are 16 22 07.2 +19 22 36. Earlier in the night, GK Per and AM CVn get the nod for northern observers. GK Per especially! In the south, we are getting great coverage of RX1155-56, the bright new dwarf nova. But everyone switched in unison to this target from V803 Cen... leaving our old friend high and dry. ("Everyone" meaning Berto, Bob Rea, Neil Butterworth, and Greg Bolt). How about giving V803 Cen some attention too? We'll be wanting to cover both for a quite long spell. Many new features at the website... preprints of WZ Sge and others, and an atlas of orbital light curves. With banners at the homepage. joe From jk at cbastro.org Sun Apr 7 17:42:43 2002 From: jk at cbastro.org (Jonathan Kemp) Date: Sun, 7 Apr 2002 11:42:43 -1000 (HST) Subject: (cba:news) new CBA web site features Message-ID: Dear CBAers, As Joe mentioned briefly earlier, there are quite a few new additions to the CBA web site... We are pleased to now include preprints of our WZ Sge and RX 2329+06 photometry papers at the CBA web site in PDF format. Please note that the WZ Sge preprint is quite a large download. Also, the HT Cam preprint should appear within a week. Additionally, for those of you who may not have visited recently, we have added two new sections to the web site lately. First is a growing atlas of the mean orbital light curves of CVs -- a project which will continue to develop over the coming months and years. Second is a presentation entitled "Hump Zoology of CVs" which concisely summarizes various periodic phenomena found in CV light curves. This section is also appearing as an appendix in the WZ Sge paper. Please enjoy these newly-presented features! Also, if you are a co-author of one of our recent papers and would still like a hardcopy of a preprint, please let me know and I'll happily send one. Cheers, Jonathan CBA Hilo From jop at astro.columbia.edu Wed Apr 10 18:33:47 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 10 Apr 2002 18:33:47 -0400 (EDT) Subject: (cba:news) a new CBA green-light special Message-ID: Dear CBAers, It's time to start work on what may become the CBA northern target of the year... a 12.6 magnitude star in Hercules with an apparently complex set of periodic signals - fresh meat for our period-finding machinery! This is RX J1643.7+3402, also called "Her" in the electronic Downes et al. CV catalog. Exact coords are 16 43 45.72 +34 02 40.2. As you'll see from the Downes et al. chart (available at the CBA website), it's only about 1.3 arcmin W of a 6th magnitude star... so you might want to think about that in accounting for sky brightness (since bright stars harass their neighbors). A very nice V=12.97 comp star exists another 1.5 arcmin NW from the variable. Let 'er rip. Those of you who can work well at 16th mag should get some more coverage on V589 Her (and send also to Tonny). That's turning out well too, but the star is getting faint. Earlier in the night, the targets of choice are GK Per and GP Com. We should DROP AM CVn - we have a very fine orbital (1028 s) pulse timing and don't need more until (possibly) late in its observing season. And as for the south, V803 Cen and RX1155-56 are keeping up their grand show. PLease don't forget V803 - I know the light curve doesn't look as glamorous as RX1155 now, but the payoff of loyal coverage will be great! Happy observing! Joe From jop at astro.columbia.edu Fri Apr 19 14:45:19 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 19 Apr 2002 14:45:19 -0400 (EDT) Subject: (cba:news) V2051 Oph and stars of April Message-ID: Dear CBAers, Peter Nelson and Rod Stubbings report a fresh outburst of V2051 Oph. Though not yet certain, it's likely to be a super... and an April superoutburst of this star gives us another chance for excellent coverage of an eclipsing SU UMa going through all outburst stages. Notre specialite! We have serious competitors for southern attention now, in RX1155-56 and V803 Cen. RX1155-56 is back near minimum but still humping away at the usual superhump period... so I think it's timely to abandon it for a couple weeks, by which time it should have gotten over the shakes (and started up a respectable *orbital* signal). V803 Cen is tougher to figure out... but I'd lessen the priority of that too (though please don't forget about it, we'd greatly like to keep count of its rapid cycles throughout the observing season). I think V2051 Oph deserves top billing after it rises. In the north, I recommend RX1643+34 for the small scopes, and perhaps for everyone after the moon gets bright in a few days. In the early evening, how about GP Com? This is a tough target at 15.7, but should be a high priority for us since it's another double-white-dwarf star (like AM CVn)... these guys have always been good to us. Anyone else (other than the Kiwis) going to the New Zealand Photometry conference in early September? I'm going for sure. Could be a CBA mini-meeting there. joe