From jop at astro.columbia.edu Sun Oct 3 12:43:36 1999 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 3 Oct 1999 09:43:36 -0700 (MST) Subject: (cba:news) stars for october Message-ID: Hey there CBAers, Sorry for my very long (but predicted) absence. I'm now ensconced out at Biosphere 2, running the Universe Semester program. On the plus side, it's wonderful to be surrounded by so many stars at night, with the Milky Way arching from horizon to horizon. It has been a (relatively) wet summer, so the animal population is in superabundance - many deer and wild pigs (javelinas) roaming the grounds, along with rabbits, coyotes, and a solitary cougar. And billions of grasshoppers this month, some as big as 6 inches long. What a splendid profusion of wildlife, just what this city dweller needed. I'm teaching classes every morning and afternoon, and with practically every night clear, I'm vastly overextended. Major flaw in the planning. Anyway, the main result is that I've been very slow in taking care of all CBA business, for which I apologize. This will change soon! (Now, actually.) Recently Dave West obtained 4 straight nights of photometry of AO Piscium, revealing to my amazement a new period slightly shorter than Porb. This is presumably one of our stocks-in-trade (negative superhumps), but I was still amazed since it had not been detected before in 20 years of photometry. Did the star change, or was our coverage simply better than anything previous? I dunno. Anyway, this is now a very high priority item: pick up AO from an eastern tree and follow it down into a western tree. We should do this star throughout October. You'll notice that the field is really sparse - Dave managed to find a comp star 1 mag fainter than AO, which is good enough (Dave, can you send the coords/offset of that star to the "news" e-mail exploder, so people can identify it). AO Psc is right on the equator, nice and friendly for all observers. We particularly value non-USA observations since that's where our coverage is most lacking - but the truth, asusual, is that we need observations from all sites (even when you think you're overlapping with someone else, you're probably not - and when you are, it supplies critical calibration information). The other two good DQ Her stars for coverage now are V709 Cas (RX0028+593) and FO Aqr. I wonder, are we going to find negative superhumps there too, now that we know how to look for them? All nice and bright, can hold their own against most invasions by moonlight. I'll be here through December 20. And thrilled to get a visit from any of you. I really underestimated how astronomically lonesome I would get out here! As some of you know, Gordon Garradd is spending most of the (northern) fall with us, so there's some CBA presence outside of me and Jonathan. joe From jop at astro.columbia.edu Sun Oct 3 14:00:25 1999 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 3 Oct 1999 11:00:25 -0700 (MST) Subject: (cba:news) V751 Cyg Message-ID: Oh, I forgot to mention V751 Cyg. This was a great campaign, one of our best ever! Very fine contributions from Dave East, Cap'n Bob, and Lew Cook. We certainly could use some help from other longitudes, especially if you actually have the data in hand. The star showed all the normal signatures of negative superhumps, and quite grand ones at that. By the way, John, would you buy this star as an SW Sexer? No trace of Porb in the light curve. We have a 20 day campaign, possibly enough. There's merit in tracking the signal over longer baselines, though - so continue if you like this star. (I just wanted to promote AO Psc vigorously in the the last message since that's one we need to get newly organized for. joe From jop at astro.columbia.edu Thu Oct 7 10:49:59 1999 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 7 Oct 1999 07:49:59 -0700 (MST) Subject: (cba:news) AO Piscium, the lonely one Message-ID: It's lonely in the skies (lack of nearby comparisons) and lonely in the CBA coverage (so far Dave West only). Yet it's pulsing away with the biggest 14 minute amplitude ever and a freshly minted superhump - where none was observed, expected, or even guessed before. WHO WILL BUY this wonderful star? We urgently need more coverage from all observers, and we're *begging* observers from non-Arizona longitudes. It's probably a *negative* superhump, but only an extended-longitude study can test this for sure. Dave's comparison star is about 1 mag fainter than AO - see if you can find and use this guy (Dave, can you send the offset position to cba-news at cbastro.org). This was my favorite star in the summer of 1980. Never dreamt it had so much life left in it! joe From jop at astro.columbia.edu Wed Oct 13 20:37:58 1999 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 13 Oct 1999 17:37:58 -0700 (MST) Subject: (cba:news) IP Peg Message-ID: Hey there CBAers, Congrats for all the action on AO Psc. We're still hurting somewhat for non-USA coverage, but the light curves have been of really exquisite quality. I think we're probably ready to call off the intense campaign. And IP Peg has erupted, a star made to order for CBA coverage. I think the borealites should swing their telescopes over to IP Peg and let 'er rip. Does this star, too, superhump? joe From jop at astro.columbia.edu Thu Oct 14 07:42:48 1999 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 14 Oct 1999 04:42:48 -0700 (MST) Subject: (cba:news) AO Piscium Message-ID: Well, I did a little more analysis on AO Psc, whose 14-minute pulse is booming away this year as it has not since discovery in 1980. The coverage in North America is superb (mainly Dave West, Lew Cook, Cap'n Bob), and fine details of the pulse behavior are easily apparent. As is the orbital signal at 6.70 c/d. But there is a signal at lower frequency, not seen before but in the range associated with a superhump. This occurs at 5.05 or 6.05 c/d, and we cannot tell the difference even with the many 6-hour runs we're getting. Lasse Jensen has started observing it from Denmark, but is plagued by the lack of comparisons, the lack of aperture, the southerly dec, and, well, Denmark. So we really, really need observations from other longitudes! (I thought I could resolve the alias from the present data, but find that I cannot.) I hear from Alon Retter and Dan Rolfe that some observations may occur over the next week from Israel and the Canaries, which would help a lot. And the Kiwis often deliver big-time (esp. Marc Bos and Stan Walker), though I usually find out much later. These are merely scheduled observations, but the importance of all this is very high (apsidal superhumps in a DQ Her star, that's a first) and continued coverage over the next week from USA longitudes is very desirable - despite what I said in the last message! I think IP Peg is very peachy too. The weather has been so good in the southwest that I'm feeling greedy. Can we get 'em both? joe Kiwis don't feel neglected - I hope that you'll be able to break this alias! And you *certainly* will find the antics of this star in 1999 awesome. From jop at astro.columbia.edu Mon Oct 18 17:15:30 1999 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 18 Oct 1999 14:15:30 -0700 (MST) Subject: (cba:news) AO Piscium, the curtain falls Message-ID: Olde Whiteface is getting too close to AO Psc, and will remain too close for 5 days. I think it's *now* time to end the campaign. IP Peg is no picnic either, but should possibly stay visible as the Moon never gets closer than about 16 degrees. That's a good one for continuing coverage. The new kid on the block is V709 Cas, nee RX0028+593. Time to start that campaign up in earnest. The bright-star replacement is V592 Cas, probably the best one for the bright nights which lie immediately ahead. Sorry they're all northern, but I'm hoping the southerners can help us on IP Peg! joe From jop at astro.columbia.edu Fri Oct 29 10:11:47 1999 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 29 Oct 1999 07:11:47 -0700 (MST) Subject: (cba:news) stars of november Message-ID: Dear CBAers, Well the endless clear and sunny weather in southern Arizona continues unabated. Sounds wonderful I'm sure, but we haven't managed to get *any* photometry out of it here at Bio2, and don't expect to as long as our students are here. This may seem totally weird - I can't claim to understand it, but I suppose it just reflects the fact that love for research is actually a very odd quality, not at all with mass appeal (though the idea of it is very popular). So education trumps research here. With *much* preparation in future years, I think this can be changed, though. We have a very fine campaign going on IP Peg, starting from the recent outburst. This is a grazing eclipser, in which one can readily study the structure of the bright spot as it gets eclipsed (since the central disk is not eclipsed, or not much anyway). Let's track it down all the way to the new year. Dave East, Cap'n Bob, Lasse, and Tonny (welcome back Tonny!) have been tracking it. And a few days ago, U Gem erupted - the other grazing eclipser up there. Same deal for Mister U Gem. But U Gem will be with us in the sky all the way to May. So in principle we can watch the structure of the bright spot change all the way from the present eruption to quiescence to the next eruption 100 d later, then all the way to the next one. U Gem is, after all, royalty - deserves this kind of treatment. U Gem's great brightness, though a scourge to some of us, is also a good way to reach out to our brethren of modest aperture. I continue *enormously* interested in pulse timings of DQ Her stars: FO Aqr, V405 Aur = RX0558+5353, BG CMi, RX0757+63, and AO Psc (the campaign on AO Psc is over but scattered pulse timings are still good). Let's keep up the campaign on RX0028+593 = V709 Cas. This has quite a weak pulse - a good target for those with bigger scopes. Requires long nightly runs, and preferably a bunch in a row. The aforementioned dwarf novae (IP Peg and U Gem) can be hit more infrequently, except when they are actually erupting. Two CBA papers in the present issue of PASP, by the way. You might want to check your neighborhood newsstand. Jonathan, could you put 'em on the website? Back to class struggles. It's a very lonely place out here, I'd love to hear from you! Joe