From jop at astro.columbia.edu Mon Oct 13 11:55:31 2003 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 13 Oct 2003 11:55:31 -0400 (EDT) Subject: (cba:news) New and old stars Message-ID: Dear CBAers, Lotsa progress lately. Time for some reports. The 20-star paper just came out in PASP (Nov 2003). The preprint version is posted on the CBA website, and differs only slightly. V551 Sgr and RU Hor are dwarf novae that have run their course. Exit both. Now we hope to find their *orbital* periods through some other means. The campaign on V1101 Aql, primarily waged by Dave Messier and Tom Krajci, is going great guns. This star has a very strong 3.9 hour signal, and something else at low frequency that may or may not be periodic. It has the whiff of a negative superhump. With continued coverage, we'll know in a few weeks whether that low-frequency thingamabob is stable, and also whether Pspec agrees with Pphot. Superb target for northerners... but very nice for australites too, because even quite brief time series will fill in critical points in the long-term light curve (i.e. elucidate the low-frequency activity). Wonderful star! DI Lac and Cyg 1. Unnhhhh. These stars tantalize but haven't yet delivered the goods. I think they should be swept off the stage, unless the spectroscopists (I assume John) sweep them back on. OR And. That was a very nice campaign, with many participants (Foote, Fried, Krajci, Skillman, Novak, Oksanen, Cook)... and gave a very clean signal at 0.1359(1) d. Probably that's Porb, though it still awaits confirmation from spectroscopy. We got a 20-day baseline and pretty dense coverage; that's enough. MANY new northern targets swing into view in October. I dunno why (unlikely things happen!) but there are a host of DQ Her stars (intermediate polars) and candidates in the general vicinity of 5h+60 deg. These are red meat for CBA studies. I guess the two best are: Cam RX0625+73 FS Aur 0547+28 "Best" since they are certifiably interesting, somewhat unstudied, and offer a strong periodic signal for study. More speculative are: Cep 0506+83, or HS0455+8315 Aur2 0614+45 Not much known yet about these guys. The latter has a fast periodic signal (87 min) reported, but it was weak (just 1%)... so would need a *lot* of coverage. And V405 Aur. A definite DQ Her star... but very strong oscillations, and with no good study of Pdot or detailed period structure, it's time for us to remedy this. So a great month for the north. The best star for long coverage in the south now is AH Men. We have a big storehouse of data wanting to come out... and one more year of coverage will definitely bring it out of hiding. Very, very rich spectrum of periodic signals, and a *bright* star (12.7 or so). AO Psc and FO Aqr continue to be good for any hemisphere you might happen to think of. joe From jop at astro.columbia.edu Fri Oct 17 01:10:57 2003 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 17 Oct 2003 01:10:57 -0400 (EDT) Subject: (cba:news) a few updates Message-ID: Dear CBAers, As many of you know, V1101 Aql has been in some sort of an outburst the last few days. I dunno what kind of an outburst it is - possibly a dwarf nova - but the star's photometric wave appears to maintain a constant amplitude in intensity units as the light level moves up and down. Pretty interesting! Definitely worth staying for another few weeks, despite the somewhat awkward sky placement. Here's another good northern star: LD 317, known as "And" in the CV catalogue. Not much known about it yet. We got a coupla nights at Kitt Peak before the observing run ended; now it's time to turn the CBA guns on it. No change in the south. Jennie McCormick started up the campaign on AH Men. May it prove a winner - that star has been mighty kind to us. For the past several weeks we have effectively lost access to VSNET, and many efforts to get it restored have failed. This handicaps us greatly in our ability to respond to news of new dwarf-nova outbursts. I'd be grateful if cbaers could help me keep informed about such things (and other potential targets for campaigns)... and perhaps be more aggressive about using cba-news. We have a pretty small mailing list, so don't think you're spamming the world. Thanks! joe From jop at astro.columbia.edu Mon Oct 27 22:37:00 2003 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 27 Oct 2003 22:37:00 -0500 (EST) Subject: (cba:news) November stars Message-ID: Dear CBAers, Sorry I've been so quiet lately. Still in mourning after that Game 7 Red Sox loss, you know. Some news about campaigns. The response on FO Aqr has been really good, especially from Bob Rea. We've got enough, and can shuffle it off stage for the rest of the year. Likewise, FS Aur can be demoted. It still shows its usual (and baffling) 3.4 hour variation... and we can just track it over the years. Off until further notice. V1101 Aql has been superb - well observed by Dave Messier and Tom Krajci. It has powerful negative superhumps, which maintain a constant strength (in energy units, not magnitudes) as the star ramps up and down from maximum to minimum light. It will be lovely to carry out an extensive campaign on this next year, when the star is better positioned. But even this abbreviated campaign is plenty informative. Still, the seasons grind onward, and it's time to leave the star. Here's a good menu for the next month. Lotta stuff in the north. Two evening stars, LD 317 ("And" in the CV catalogut) and "Peg" (at 23 09 49.2 +21:35:18). Then some far-northern guys: HS0455+83 ("Cep") and RX0625+73 ("Cam"). A quieter time in the south. I most strongly recommend three stars: AH Men, our old friend; EF Tuc, which might become a new one; and possibly the SDSS star at 0407-06 ("Eri" in CV Catalogue) which Berto has written about. I don't really know anything about the latter - but it's definitely of great interest when it erupts (possibly too faint at quiescence). I promise to reform and write more! By the way, Jonathan and I are still excluded from receiving notifications of dwarf-nova eruptions through vsnet, and this seems unlikely to change. I would greatly appreciate it if any of you receiving those notices would help keep us informed. Thanks! joe