From jop at astro.columbia.edu Tue Aug 2 14:27:58 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 2 Aug 2005 14:27:58 -0400 (EDT) Subject: (cba:news) Month of the dragon Message-ID: Dear CBAers, Sorry to have been so quiet lately. Holed away in a little cabin in Vermont, with no hope of email access... or even a telephone. But I'm back in action now! I basically analyzed all the data on V345 Pav and MV Lyr, the currently popular targets du jour. The data on V345 Pav, from Berto and Greg Bolt, show a beautiful orbital light curve, but none of the periodic signals which are our bread and butter. So scratch that one. MV Lyr is definitely an odd case, occasionally breaking into 3-hour humps, but not showing any persistent period (i.e. anything hanging together for more than a few cycles). Scratch that one too - we may or may not have learned anything useful, but the coverage so far is probably as good as it's not going to get. Time to move on to other stars, and to finish the analysis. In the far north, may I commend three stars in Draco: IX Dra and MN Dra, for the reasons I stated earlier - in a previous message. For these stars, we'd like snapshot mags too, not just differential time-series as is our usual wont And a new Draco entrant: HS1813+61 ("Dra"), reputed to be at Po-0.148 d although really with very little known about it. In the south, I recommend V1494 Aql (technically north, but still...). Bob Rea's recent data shows that the light curve looks more like a regular eclipse... and we need one more season to reach critical mass for our seasonal light-curve study. Then there's V1327 Aql, with an outburst - maybe the very first outburst ever observaed - announced by Rod Stubbings. No knowledge of that star. Whatever you learn about it, you'll be the first! more tonight/tomorrow. joe From jop at astro.columbia.edu Tue Aug 2 20:39:49 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 2 Aug 2005 20:39:49 -0400 (EDT) Subject: (cba:news) v1327 aql Message-ID: Thanks David, for clarifying the magnitude of V1327 Aql. At 16.7 this is not so attractive a target. Probably it means that we will not be able to mount an effective campaign in the few days we (probably) have... so I'm disinclined to promote it. MN Dra and IX Dra can get similarly faint, or fainter, but these stars erupt a lot and seem to have a superhump history which is pretty odd. Plus they're attractive targets for snapshots, not just time series. Add 'em to the other Mister Dra (the HS1813 star), and that's lots of work for northern observers. joe From jop at astro.columbia.edu Tue Aug 23 07:48:33 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 23 Aug 2005 07:48:33 -0400 (EDT) Subject: (cba:news) (No) curtain call for RZ Gru Message-ID: Dear CBAers, Time marches on, and the script calls for RZ Gru to exit stage left. It's been a good campaign, mainly Berto plus the usual New Zealand powerhouses... and will take me a few weeks to analyze fully, but I can see from a quick look that we'll profit more from new targets than from repeated observation. So away with it - we'll see if it surrenders a period at last. Still a good southern target, and one never observed before with time series, is V1082 Sgr. At 15th mag it should give a pretty good signal - let's visit a while before the Sun drags it away. And in morning skies, there's VZ Scl. At 3.5 hours and eclipsing, it's somewhat criminal that we've never observed it before. Such stars are prime candidates for superhumps, and often flash other showy credentials when closely examined. Help us avoid serious jail time by starting up the year's activity on VZ Scl. About 15.7, a nice challenge to get good signal-to-noise in the time series. And IN THE NORTH... I still hunger greatly for coverage of MN Dra and IX Dra. Even snapshot mags in the low state have value. But not much CBAer interest yet. The response to "Dra" (HS1813+62) has been better, with contributions from Dave Messier, Lew Cook, and Michael Richmond. But the time series still needs some more *density* to acquire serious punch. A late-season effort on Mister Dra would be just great! FINALLY (all hemispheres)... There's also the possibility of jail time for failing to observe AE Aquarii for lo-these-many-years. With small and mainly filterless scopes, we're not well equipped to observe it. Yet it's bright (11-12), transits at local midnight, nicely perched on the celestial equator, is deeply entangled in some awfully interesting magnetospheric physics (because of its rapid 33 second rotation)... and will be the target of practically every space telescope this August 31-Sep 1. So starting now, we really ought to be accumulating light curve to support these space observations. You'll see that AE Aqr is often just dead flat in the light curve - with flares erupting every few minutes to every few hours. By far the best method is to use a blue filter (to subdue the unwanted light from the secondary, and isolate the flaring region). But unfiltered time series will still be plenty helpful. All the other time-series photometry considerations apply normally. More on this as the coordinated observation dates approach. So there's a new August/September menu. I'm just going off for some late summer family time before school starts. The northern-USA heat wave has finally broken (today), and now I'm heading off to northern Maine where the ocean temperature never exceeds 53 degrees F! joe From jop at astro.columbia.edu Tue Aug 23 07:56:13 2005 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 23 Aug 2005 07:56:13 -0400 (EDT) Subject: (cba:news) [vsnet-newvar 2553] (fwd) Re: New object near M27 (Renz) (fwd) Message-ID: Dear CBAers, Most of you have heard by now of the probably eruptive and maybe strange object just found in the field of the Dumbbell Nebula. It's certainly a blue star, and that makes it more or less one of our boys. Probably a distant dwarf nova, and maybe too difficult a target for us... but it's too cute a discovery to let pass without notice. On the chance that it might be an SU UMa (50-50 I guess), we might even be able to spot superhumps and thereby get a measure of the period. "We" meaning you. If you like this sort of thing, give it a rip! BTW the "mouse-over" thing below is particularly nice. joe ----- Original Message -----=20 From: Wolfgang Renz=20 To: Arne Henden (AAVSO) ; Aaron Price (AAVSO) ; Dan Green (IAU)=20 Cc: J=F6rg Hanisch ; Hans-G=F6ran Lindberg ; R Jay GaBany=20 Sent: Monday, August 22, 2005 7:11 AM Subject: New object near M27 Hello I pushed it a bit tonight on the pretty-picture email lists. R Jay GaBany came up with a M27 image in progress (RCOS 20 inch, STL-1000XM unbinned RGB) made on June 5, 6 and August 11, 2005 that is much deeper and much sharper than the DSS plates. He made a nice mouse-over with the discovery image of Joerg Hanisch that shows that its a new object with an amplitude of at least 4 mag: http://www.cosmotography.com/images/m27_mystery_snipit.html The discovery image of Hans-Goeran Lindberg, who also anounced the new object, wasn't as deep and with a shorter FL. Up to now there are negative detection reports till August 11 and posive ones starting on Aug 16. There is also some photometry from last night: V=3D16.17 +/- 0.01, I=3D16.00 +/- 0.04, CV =3D 16.67and 16.69 mag. If its not a nova could it be a SN in one of the faint galaxies around M27 ? http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?in_csys=3DEquatorial= &in_equinox=3DJ2000.0&lon=3D19%3A59%3A51.29&lat=3D%2B22%3A42%3A32.3&radiu= s=3D20.0&search_type=3DNear+Position+Search&out_csys=3DEquatorial&out_equ= inox=3DJ2000.0&obj_sort=3DDistance+to+search+center&of=3Dpre_text&zv_brea= ker=3D30000.0&list_limit=3D100&img_stamp=3DYES&z_constraint=3DUnconstrain= ed&z_value1=3D&z_value2=3D&z_unit=3Dz&ot_include=3DANY&nmp_op=3DANY Clear skies Wolfgang From: "Wolfgang Renz" Subject: Re: [vsnet-alert 8631] Re: New object near M27 Date: Mon, 22 Aug 2005 08:07:11 +0200 Hello Kato-san Is it possible that outburst were overlooked by the pretty picture folks = for decades ? I decided to push it tonight, when I didn't see any trace of it on the = DSS 2 infrared and the 2MASS J, H, Ks images.=20 http://www.astrouw.edu.pl/cgi-asas/asas_2mass_html/195951+2242.5 So it couldn't be a very red object that appears much brighter in the = unfiltered CCD images of the two discoverers. Clear skies Wolfgang --=20 Wolfgang Renz, Karlsruhe, Germany Rz.BAV =3D WRe.vsnet =3D RWG.AAVSO