From jop at astro.columbia.edu Fri Jun 6 20:51:18 1997 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 6 Jun 1997 20:51:18 -0400 (EDT) Subject: (cba:news) stars of june Message-ID: <199706070051.UAA09499@tristram.phys.columbia.edu> Dear CBAers, June 6, 1997. I'm about to leave on a 16-day trip with only an occasional pot-shot at e-mail here and there. So I'm sorry if I get kinda quiet for a while. More seriously, quite a few CBAers will be away from their nocturnal posts during June 8-12, more or less the dates of the AAS meeting in North Carolina. Just what happened in northern France in June 1944. Only worse in our case, since at least the invasion hadn't yet happened when all those German generals went on holiday. In our case the invader of the night sky is well known to us, the outburst is evolving, and here we are going off to sip wine and curry favor with mere outlanders! Shocking. I assume everybody got the newsletter by now. We (mostly Jonathan) have also cooked up a fancy brochure, which is basically a small version of our AAS poster - but which also explains what we do to a (borderline) nontechnical audience. It should be somewhat useful for recruiting, and will also maybe help explain what you're doing to your spouse. We're pumping them out fast and will send a dozen or more to all members requesting them. V844 Her (= "Var43 Her") was humping away vigorously with an 80 minute period until June 4. Now it seems to have dived down to 17th mag, and the humps are very hard to spot (though still present). Might come back up, a la EG Cancri in December 1996. It's a target of great importance for much that we hold sacred. Please track it as far as you possibly can on the decline branch - and then beyond, since we want to be vigilant for echo outbursts. I'm sorry that there's no easily available finder chart. You could possibly get something from the various CBAers who have been tracking it (Harvey, Skillman, Vanmunster, Jensen, Fried, and now Stull). Or you could study these directions: 2000 position is 16 25 01.7 +39 09 26. The vicinity looks like this: A B V C Usual orientation (north up, west to the right). V is the variable, and the A->C distance is about 60 arcsec. A is about mag 14-15, B and C about 16. The next closest star brighter than mag 19 is a 15 mag star 2 arcmin north of the variable. Also, there's a galaxy 5 arcmin WSW from the variable. Not a difficult field at all. Most people have been using a bright comp (mag 12.3) 3 arcmin NW of the variable (slightly off this scale). You might want to change that now that it has dived faint. Oh, and there's a very bright star, probable SAO, 5 arcmin NE from the variable. In practice, I realize that most of you would rather work on something brighter. So after checking V844 Her, just truck on over to AM CVn or EC1533-14 (now christened HP Lib) and get a pulse timing. These campaigns have suffered from all the excitement in Hercules. Then there's V603 Aql - bright time in June is definitely a good time to get rolling on Mister V603. For southerners, you know the tune - still V803 Cen, as long as you can, with EC1533 and V603 Aql for the rest of the night. We'll send *everyone* one brochure, and we'll send more for anyone who wants 'em. Fan mail to Jonathan, as usual. joe From jop at astro.columbia.edu Thu Jun 26 18:15:28 1997 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 26 Jun 1997 18:15:28 -0400 (EDT) Subject: (cba:news) summer stars Message-ID: <199706262215.SAA13610@tristram.phys.columbia.edu> Dear CBAers, June 26, 1997. Back now from the round of June meetings. No great things coming out of them, but several very promising inquiries arriving at our website while we were gone. Some good expansion prospects in Russia, Western Australia, New York, and Colorado. All sites that we would greatly welcome. I wanted mainly to cover program stars for June/July. For the small telescopes, the best targets are V Sagittae and V603 Aquilae. That's it. Pound 'em into the ground. Both very bright, about 11.5, and surviving any conditions of moonlight. FO Aquarii would be a nice project too, very entertaining with its 21 minute pulse. The bigger telescopes have a more complex menu. In the early evening, we still want timings of AM CVn (especially) and HP Lib = EC1533-1403, as long as you can get 2-hour runs on them (after the runs get shorter, we declare the seasons over). But we also want to keep a very close watch on V844 Her = Var43 Her, now at magnitude 17.5 but still seemingly humping away. For those of you with already a commitment to this star (esp. Dave E and Dave W), I recommend keeping it up; I realize the data *look* ugly, but they seem to be paying off in the overall time series. Later in the night, there's V503 Cyg, an old buddy which we deserted for a couple years. It's a great permanent negative superhumper, and it's time to make friends again. It's about mag 17.2, sorry about that, but the superhump is about 0.4 mag amplitude, plenty big. We should hit it hard, long, and often throughout the summer/fall. That's also true for our old friend RX1940-10 (=Aquila 1 in Downes-Webbink-Shara 1997), now back in the sky. Brighter (averaging about 15.6) and with a very large hump, about 0.5- 0.7 mag. For the larger telescopes, it's perhaps best to declare allegiance to either RX1940 or V503 Cyg depending on your aperture and latitude. Lemme know which one you'll go for, and I'll keep people apprised of wha's happenin'. Oh, and FO Aqr is fine for short observations with any size telescope and pretty much any moonlight. With a large 21 minute pulse it's hard to go wrong. Naturally we always like the long observations though! This star will give you something really nice to hang on your mantle. If you're just starting in this business, by the way, I recommend V Sge, because the light curve is relatively predictable (not entirely), and it will be easier to evaluate the data. I'm also writing a paper on the star now, and am maximally motivated to provide that evaluation! The comparable southern/equatorial target is V603 Aql. Finally... Last year at this time, the Europeans got some good data on DQ Her, and I said we would mount a serious effort in 1997. I was planning to welch on that promise. However, Dave Skillman just got five straight nights on the star, and we do have a 2-week dark run starting now. It would be *awfully* interesting to know if DQ Her showed superhumps (totally forbidden by all theories of course!) - and last year's data was kinda tantalizing. The star's certainly well placed. So, Lasse and Tonny, let's say that if you get a good weather streak in the next 5-7 days, go for long runs on DQ Her, tell us by cba-info, and we'll support it in North America. I'm a bit reluctant to starve some of these other stars which are sure winners, but this may be a big chance. (But if your weather's bad, let us know that too, so we can be undisturbed by Mister DQ.) joe From jop at astro.columbia.edu Sun Jun 29 20:12:06 1997 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 29 Jun 1997 20:12:06 -0400 (EDT) Subject: (cba:news) hercules competitors Message-ID: <199706300012.UAA20043@tristram.phys.columbia.edu> Down with V844. Forever - the humps are gone. Up with DQ. For the next two weeks, as often as possible. joe From jop at astro.columbia.edu Sun Jun 29 20:12:06 1997 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 29 Jun 1997 20:12:06 -0400 (EDT) Subject: (cba:news) hercules competitors Message-ID: <199706300012.UAA20043@tristram.phys.columbia.edu> Down with V844. Forever - the humps are gone. Up with DQ. For the next two weeks, as often as possible. joe