From jop at astro.columbia.edu Sat Feb 5 19:41:49 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Sat, 5 Feb 2000 19:41:49 -0500 (EST) Subject: (cba:news) New SU UMa discovery from CBA-Italy Message-ID: Just when you thought it was safe to go observing again.... Gianluca Masi and Alessia Cassetti report periodic humps from a newly observed dwarf nova (with the eruption found earlier tonight by Patrick Schmeer). The star is called "Tau 3" in Downes, Webbink, and Shara 1997, and more officially rendered as RX J0459.7+1926. It's about 15th mag tonight, and given the large-amplitude superhumps the Italians are seeing, this is probably about the maximum brightness. I was hoping that we could turn fuller attention now to BY Cam (Brian Martin getting some fine-looking data!) and CN Ori (Robert Rea and James Hannon, likewise), but I have to admit that this is a good opportunity to get global coverage on Tau3. It's a little late for Taurus, but if we can paste North America (and AU/NZ??) onto Europe, we can effectively get long runs and hence solve the 24-hr alias problem. Also, it's an entirely new toy - gotta give some credit for that! I think it's suitable for at least a quickie, a 5-day job unless something really strange/interesting pops up. Of course keeping the faith on CN Ori and BY Cam would be plenty reasonable too. Takamizawa V85 was officially renamed IY UMa, a pretty dull name for such a swashbuckling star. We've been getting some wonderful data at its 17th- magnitude state ("post-superoutburst", "quiescence", or what-have-you), and have covered about 30 eclipses now. Discrete white-dwarf and hot-spot eclipses appear, and it's possible to measure the radii and luminous contributions of each. Fun fun fun. I'll send out a much fuller thing on it in about 2 days. joe From jop at astro.columbia.edu Mon Feb 7 16:26:00 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 7 Feb 2000 16:26:00 -0500 (EST) Subject: (cba:news) FS Aurigae Message-ID: FS AUR Gary Poyner's announcement of a brightnening in this star, a dwarf nova candidate, brings up some history. We in the CBA have been tracking the star episodically for the past two years, and it shows a pretty well-defined photometric period of 0.143 d (with no information yet about how, if at all, this depends on luminosity state). Yet John Thorstensen (the "horse's mouth" on such matters) firmly avows that the radial- velocity period is close to 0.0595 d. We've been trading "are you sure?" queries for two years. Well, at this point we *are* sure, but haven't the foggiest idea why the star should have two very well-defined, stable, and incommensurate periods. Wouldn't you like to help us find out? Photometry in the higher brightness state (perhaps not quite right to call it an "eruption" but anyway brighter) is likely to help us a lot. Will the signal be enhanced? reduced? destroyed? Who knows... there are precedents for all, and its actual behavior is likely to guide us along to find the right answer. So we're doing a CBA campaign on the star right now, and would greatly welcome your contributions! Joe Patterson CBA-New York jop at astro.columbia.edu www.cbastro.org From jop at astro.columbia.edu Mon Feb 7 16:26:00 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 7 Feb 2000 16:26:00 -0500 (EST) Subject: (cba:news) FS Aurigae Message-ID: FS AUR Gary Poyner's announcement of a brightnening in this star, a dwarf nova candidate, brings up some history. We in the CBA have been tracking the star episodically for the past two years, and it shows a pretty well-defined photometric period of 0.143 d (with no information yet about how, if at all, this depends on luminosity state). Yet John Thorstensen (the "horse's mouth" on such matters) firmly avows that the radial- velocity period is close to 0.0595 d. We've been trading "are you sure?" queries for two years. Well, at this point we *are* sure, but haven't the foggiest idea why the star should have two very well-defined, stable, and incommensurate periods. Wouldn't you like to help us find out? Photometry in the higher brightness state (perhaps not quite right to call it an "eruption" but anyway brighter) is likely to help us a lot. Will the signal be enhanced? reduced? destroyed? Who knows... there are precedents for all, and its actual behavior is likely to guide us along to find the right answer. So we're doing a CBA campaign on the star right now, and would greatly welcome your contributions! Joe Patterson CBA-New York jop at astro.columbia.edu www.cbastro.org From jop at astro.columbia.edu Mon Feb 7 16:26:00 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 7 Feb 2000 16:26:00 -0500 (EST) Subject: (cba:news) FS Aurigae Message-ID: FS AUR Gary Poyner's announcement of a brightnening in this star, a dwarf nova candidate, brings up some history. We in the CBA have been tracking the star episodically for the past two years, and it shows a pretty well-defined photometric period of 0.143 d (with no information yet about how, if at all, this depends on luminosity state). Yet John Thorstensen (the "horse's mouth" on such matters) firmly avows that the radial- velocity period is close to 0.0595 d. We've been trading "are you sure?" queries for two years. Well, at this point we *are* sure, but haven't the foggiest idea why the star should have two very well-defined, stable, and incommensurate periods. Wouldn't you like to help us find out? Photometry in the higher brightness state (perhaps not quite right to call it an "eruption" but anyway brighter) is likely to help us a lot. Will the signal be enhanced? reduced? destroyed? Who knows... there are precedents for all, and its actual behavior is likely to guide us along to find the right answer. So we're doing a CBA campaign on the star right now, and would greatly welcome your contributions! Joe Patterson CBA-New York jop at astro.columbia.edu www.cbastro.org From jop at astro.columbia.edu Mon Feb 7 16:26:00 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 7 Feb 2000 16:26:00 -0500 (EST) Subject: (cba:news) FS Aurigae Message-ID: FS AUR Gary Poyner's announcement of a brightnening in this star, a dwarf nova candidate, brings up some history. We in the CBA have been tracking the star episodically for the past two years, and it shows a pretty well-defined photometric period of 0.143 d (with no information yet about how, if at all, this depends on luminosity state). Yet John Thorstensen (the "horse's mouth" on such matters) firmly avows that the radial- velocity period is close to 0.0595 d. We've been trading "are you sure?" queries for two years. Well, at this point we *are* sure, but haven't the foggiest idea why the star should have two very well-defined, stable, and incommensurate periods. Wouldn't you like to help us find out? Photometry in the higher brightness state (perhaps not quite right to call it an "eruption" but anyway brighter) is likely to help us a lot. Will the signal be enhanced? reduced? destroyed? Who knows... there are precedents for all, and its actual behavior is likely to guide us along to find the right answer. So we're doing a CBA campaign on the star right now, and would greatly welcome your contributions! Joe Patterson CBA-New York jop at astro.columbia.edu www.cbastro.org From jop at astro.columbia.edu Mon Feb 7 16:26:00 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 7 Feb 2000 16:26:00 -0500 (EST) Subject: (cba:news) FS Aurigae Message-ID: FS AUR Gary Poyner's announcement of a brightnening in this star, a dwarf nova candidate, brings up some history. We in the CBA have been tracking the star episodically for the past two years, and it shows a pretty well-defined photometric period of 0.143 d (with no information yet about how, if at all, this depends on luminosity state). Yet John Thorstensen (the "horse's mouth" on such matters) firmly avows that the radial- velocity period is close to 0.0595 d. We've been trading "are you sure?" queries for two years. Well, at this point we *are* sure, but haven't the foggiest idea why the star should have two very well-defined, stable, and incommensurate periods. Wouldn't you like to help us find out? Photometry in the higher brightness state (perhaps not quite right to call it an "eruption" but anyway brighter) is likely to help us a lot. Will the signal be enhanced? reduced? destroyed? Who knows... there are precedents for all, and its actual behavior is likely to guide us along to find the right answer. So we're doing a CBA campaign on the star right now, and would greatly welcome your contributions! Joe Patterson CBA-New York jop at astro.columbia.edu www.cbastro.org From jk at cbastro.org Thu Feb 10 03:25:43 2000 From: jk at cbastro.org (Jonathan Kemp) Date: Thu, 10 Feb 2000 01:25:43 -0700 (MST) Subject: No subject Message-ID: I think I've isolated the software problem causing repeat mailings of certain news messages. Thanks for bearing with us... jonathan From jop at astro.columbia.edu Fri Feb 11 20:10:52 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 11 Feb 2000 20:10:52 -0500 (EST) Subject: (cba:news) Yet another deep eclipser! Message-ID: Happy happy. Fire available weaponry at the new toy, RXJ0909+whatever (where Tonny found the deep eclipses). Whew, what a season it has been! 2000 coords 09 09 50.56, +18 49 47.2 (they tell me). Tau 3 probably ready for retirement, I reckon. joe From jop at astro.columbia.edu Sun Feb 13 11:00:48 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 13 Feb 2000 11:00:48 -0500 (EST) Subject: (cba:news) RXJ0909, mostly Message-ID: Dear CBAers, So far I haven't seen any actual data from this shiny new toy, but I know that some of you are observing it. Both Tonny and Stan report bad weather, though. Can anybody out there with *good* weather observe this beast? (RX J0909.8+1849, that is) It's fading from outburst, and the eclipse profile will certainly change as it falls down. Impeccable choice of target! SW UMa went into a very bright outburst, as some of you know. Definitely a super. It's very bright (10.6-11) so is a *great* choice for small telescopes and beginning CCD observers. I rate it a lower priority than RX0909 for scopes that can reach the latter, but it's awfully good for the smaller scopes. Tak V85 = IY UMa, well that's off the menu at last. Jonathan should have our preliminary report up on the website in a few hours. FS Aur, BY Cam, CN Ori, still our great friends. Getting slightly neglected with all that fireworks up there! joe From jop at astro.columbia.edu Mon Feb 14 23:05:33 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 14 Feb 2000 23:05:33 -0500 (EST) Subject: (cba:news) new stuff on the web Message-ID: Dear CBAers, Some new web stuff available.... *Summary of results and light curves from the IY UMa campaign *Summary of results from the DV UMa campaigns *Complete text of V803 Cen paper (scheduled for April 2000 PASP) We're still *pow'f'l* motivated on RXJ0909, so see what you can get. The star is getting faint, the Captain reports, so it may have become a project only for the bigger scopes. FS Aur and CN Ori remain peachy targets, and BY Cam is pretty groovy too. joe From jop at astro.columbia.edu Fri Feb 18 18:58:54 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 18 Feb 2000 18:58:54 -0500 (EST) Subject: (cba:news) stars of february Message-ID: <200002182358.SAA09383@tristram.phys.columbia.edu> 2/18/00 - first day of being 53; kind of a boring number (does anyone know anything interesting about this number?) Dear CBAers, Time for some major talk about targets. A lotta stuff poppin' off up there, things are getting confusing. Here goes. FS Aurigae. Still a mystery star. But we've gotten only a little this year, and there are too many other evening targets we need to cover to achieve success. Time to end this campaign I think. BY Cam. Brian Martin and Dave Skillman have covered BY Cam extensively, and with the far-northern dec we can still get long runs. So I reckon this one should have a very high priority. Do it repeatedly! The star often (but not always) has very wide excursions in light, which we need to follow to track the periodic behavior properly. Brian, I think we'll throw this project your way, if that's agreeable to you. RXJ0909.8+18somethingorother. Another mystery star, not yet clear what box it belongs to. Or maybe a box all its own. The advantage here is the deep eclipses - no big mystery should endure when you have the diagnostic power of eclipses! Tonny and Gordon have been following it pretty well, and Tonny will write up the results. It's about 16th mag now, sort of borderline for most of you. In a week we start a run on the 1.3 m, and we'll devote it heavily to RX0909. Tonny, why don't you send out the requests for observations? My guess is that it doesn't need more small-scope attention unless it erupts again; but I might be wrong, so it's your call. RXJ0459+somethingorother = Tau 3. A little dwarf nova which several of us have been observing, including Gianluca Masi and Gordon. Gianluca is writing up the paper. The star has disappeared from most of our screens, though we'll try a minimum-light study during the 1.3 m run next week. SW UMa. Damn thing erupted to 11th mag at a perfect time, transiting around local midnight. The 1987 Texas study (Robinson et al.) was I thought quite good and not in need of improvement. But some recent light curves I've seen from Jochen Pietz and Brian Martin in the present outburst are so excellent that I now think we can learn a lot of new stuff from SW UMa. Some oddities are hanging around from the 1980s outburst (funny Pdot, anomalously high period excess of the superhumps), and it's time to study 'em more. So I now think we borealites should go pretty hard on it. CN Ori. Very fine contributions from New Zealand coming in on this star. But to break aliases, we now have to make sure that we have coverage from other longitudes! Any Orion fans out there? One more month on this guy. IY UMa and DV UMa. Totally fascinating stars, but off the small-scope radar screens unless they rise again. New results up on the website. RZ LMi. I took it off the menu, it keeps getting overshadowed by eruptions of other stars. Still some life left in the observing season, so we expect to pick it up again soon. U Gem. A long-term project, let's not forget it. 4.2 hour light curves are always valuable as the eclipse will trace the brightness and location of the hot (bright) spot every time around. We want to follow this around the ~100 day outburst cycle; it's critical since the bright spot is the direct signature of the immediate mass-transfer rate, and nothing else is (once the matter settles into the disk, it gets modulated by the largely unknown vagaries of disk physics - but the bright spot is a simple GMMdot/R splash). Within a few weeks it's likely that U Gem will erupt again, and that's the time for concerted tree-to-tree observation because the spot structure should change *drastically* then. Summary: SW UMa, CN Ori, BY Cam, U Gem are the major dramatis personae, pending further surprises of course! Joe  From jop at astro.columbia.edu Tue Feb 22 09:06:11 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 22 Feb 2000 09:06:11 -0500 (EST) Subject: (cba:news) OY Car and CN Ori: Toys for Australites Message-ID: <200002221406.JAA12493@tristram.phys.columbia.edu> Dear CBAers, The South will rise again! (For unAmericans, this is a motto of the U.S. South, sort of a rallying cry if you're still grumbling about losing the Civil War. In our case the meaning is much less sinister, just referring to the extraordinary stellar fireworks hiding out in Ultima Thule this season.) Anyway, Rod Stubbings' report indicates that OY Car has gone into outburst (at about 12.0). As another deep-eclipsing dwarf nova, it too promises great rewards from extended photometric coverage of the outburst. Not yet clear if it's a super, but whether or not, calls for long coverage from our southerners. Fire at will. Speaking of which, it's time to pull the plug, mostly, on CN Ori. I received a fair chunk of data this year from Marc Bos, Robert Rea, and Maria Marsh (Kiwis all), and some also from James Hannon (Yank). Some also from Gordon in the pipeline. No really long spliced light curves, but enough to reach two conclusions: 1. The modulation at minimum light is very strong (~0.6 mag) and has a period in the range 0.1628-0.1634 d. Despite its strength, I just could not find an acceptable phasing from year to year. In part this is due to the star's excessively frequent jumps into outburst (making sparse the quiescent data set) - but even so, I really expected to find a unique precise period from the timings, and didn't. It's possible that this is actually not a completely stable phenomenon. 2. During outburst, there are small waves of a similar period, but they resist any simple attempt to connect them to the (more stable but perhaps not infinitely so) quiescent waves. In the one season of very extensive coverage (1995-6), a power spectrum revealed two signals: a 0.1629 d signal usually identified as Porb, and another at 0.171 d. Normally this would be termed a superhump, and I've occasionally called it that (informally - none of this is published). But it was slightly weaker than Porb, and a German paper from the 1980s suspected a signal at the same period *during quiescence*. Mighty peculiar, not quite like anything we've seen before (though V503 Cyg fans might have a few thoughts). We need two more advances to lead us out of this quagmire: enough spectroscopy to tell us the true Porb to 4 decimal places (Tim and/or John, this is your homework), and a long photometry campaign next year which doesn't get distracted by other celestial poppings-off. For the rest of this season, CN Ori is good to do IN QUIESCENCE ONLY - the eruption data isn't useful unless we have many long runs, and that we are giving up on. Timings of the wave in quiescence will be very useful, though. For borealites, the same stars remain top-drawer: SW UMa, BY Cam, U Gem. DW UMa fans might want to take a peek and see where the star is hanging out these days; it's likely to be a big-time target in March. Happy observing. Dave East wins the prize re 53. It hath no factors, hence I be in the prime of life for one more year. joe From jop at astro.columbia.edu Tue Feb 22 10:10:45 2000 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 22 Feb 2000 10:10:45 -0500 (EST) Subject: (cba:news) goodness gracious, Message-ID: another southern star popping off. Rod Stubbings and Andrew Pearce report that RX J0640-24 has erupted again to mag 11.5-12. There have been reports of photometric waves before, let's find out for sure now. And for people in the southern U.S., stop complaining about the Civil War and get down to business. Captain Bob and Dave West, methinks this one's got your names written on it...... joe 2000 coords 06 40 47.72 -24 23 14.5