From jop at astro.columbia.edu Mon Jul 8 19:11:19 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 8 Jul 2002 19:11:19 -0400 (EDT) Subject: (cba:news) V603 Aql, let the show begin! Message-ID: Dear CBAers, With a final crescendo - supplied by Berto, Bob Rea, and Greg Bolt - the V442 campaign has drawn to a fine conclusion. Just 25 days of coverage, but nearly every day, and nearly every longitude... a CBA special. The star shows a negative superhump throughout, of large amplitude but very simple waveform (essentially a pure sinusoid). I've even finished the paper! (OK, admittedly I also have data from 2001 and 1995, but I'm pretty happy about it since I'm sending it off - bundled with spectroscopy and with RX1643+34 - tomorrow!) So that's IT for V442 Oph. And it's now finally time to usher V603 Aql onto center stage. With our new strength in South Africa and AU/NZ, we can now get very long light curves for this star. The last time we looked thoroughly, the star showed simultaneous negative and positive superhumps. That gives us the opportunity to measure period changes in each - which should be of opposite sign, if the two types of precession are nodal and apsidal. We'll see! (I hope) At V=11.7, the star is a fine target for telescopes of any size. Neil Butterworth has been going strong on it for about a week, and obtained good data with an 8-inch. But please don't spurn it because your telescope is too proud to be caught collecting photons from such a bright star; I know telescopes can be that way sometimes, but in this case the light curves of higher quality and time resolution will repay the effort. Also, if you have filters and plenty of photons, pop in a V filter. That keeps calibration issues under better control. Love them equatorial stars... I still *crave* light curves on V533 Her! I really hope that northern observers with a little extra glass will pound the star hard for the next few weeks. Then there's V1494 Aql... the "Biosphere Nova", as I call it. That's a good alternative to V603 Aql, if your neighbors are observing V603 and you hate to just do what they're doing. Easy menu, hey? joe From jop at astro.columbia.edu Fri Jul 19 07:32:28 2002 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 19 Jul 2002 07:32:28 -0400 (EDT) Subject: (cba:news) rumblings in aquila Message-ID: Dear CBAers, Well, the V603 Aql campaign has been going very well, with ~30 nights of dense coverage. Bob Rea, Neil Butterworth, and Berto have been the main perpetrators. The star shows a very strong positive superhump at 0.1449 days. No hint of the negative superhump that dominated in 1992, and no harmonics either. Just a clear pure note, in the silence. So that means we can forget V603 for the rest of the year. On to other targets! In the north, I'm still earnestly hoping for good coverage of V533 Her before it slinks into the western twilight. It seems to have a decent positive superhump (P=7.3% greater than Porb), but the data still don't quite clinch the matter. Another 2 weeks of coverage will, though, and will define the period with high precision. It's time to promote V1494 Aql (the 1999 nova) to a position of greater honor. The 2000-1 data show that this is basically a 3.23 hour eclipsing binary. But the "eclipses" are broad and shallow affairs, not at all like CVs near quiescence. I'd guess that each year (in this early post-nova evolution) will bring a different waveform. Near the celestial equator, the star is well placed for essentially all CBAers. (19 23 05.4 +04 57 20 - 2000.0, chart on CBA website) The other nearly equatorial target for campaign start-up is V1432 Aql (right next to V1494 on the CBA chart page). This star is famous in CV history. It was mistaken for a Seyfert galaxy for more than 10 years, until an accurate X-ray position showed that it ain't the same. In the meantime, there was a flurry of papers purporting to explain how a Seyfert galaxy could have a strict 3.3 hour period! Anyway, it's a great target. Though no barn-burner at V=14.8, it has a 1 mag variation and a deep eclipse... lots of nice signal to keep one entertained. I recommend it as co-equal with V1494 Aql. You might want to choose one and stay with it - that's usually the way to attain maximum sensitivity in our period searches. Finally, there's V1223 Sgr. This one *is* a barn-burner at 13.3. For one reason or another, we've never gotten a really good campaign on it. It's a DQ Her star with a 13 minute period, and also an orbital period near 5 hours. Let's nail it this time around. A couple of weeks ago I sent off our paper on V442 Oph and RX1643+34, and also tucked in the superhump results on V795 Her and DW UMa. There was a long author list (Patterson, Fenton, Thorstensen, Harvey, Skillman, Fried, Monard, O'Donoghue, Beshore, Martin, Niarchos, Vanmunster, Foote, Bolt, Rea, Cook, Butterworth). I'll send out copies to all authors today. If you don't get it in a week, and are not overseas, feel free to complain! (Also, check the website; it may pop up there in a few days.) joe