From jop at astro.columbia.edu Mon Dec 10 07:15:38 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 10 Dec 2012 07:15:38 -0500 Subject: (cba:news) december stars Message-ID: <50C5D26A.80308@astro.columbia.edu> Dear CBAers, Time for some changes of target. Let's sweep V455 And and PX And off the stage. The season's getting too late. Also V405 Aur: we have enough. Also RX0524+42 = Paloma: we have absoltely beautiful and quite long coverage (from Tom and Enrique), which specify the enormously intricate period structure quite well! There are a bunch of DQ Her stars which are now "late season", and hence seasonal for an accurate period determination during 2012. Here they are: AO Psc, FO Aqr, V2069 cyg, V2306 Cyg, RX2123+42, and V1033 Cas. We need only a few observations of each, with each "observation" a 2+ hour time series of decent quality. Then there are mid-season stars of this type: BG CMi, MU Cam, WX Pyx, Swift 0732-13, RX0636+35, RX0704+26, and PQ Gem. Again, a 2+ hour time series will generally accomplish the needed result (an accurate pulse timing). Except for PQ Gem (for which a V or g filter is very desirable), white-light is OK. Now for mid-season targets which will especially repay LONG time series. 1. WX Ari. Now in a low state around 17-17.5. No time-series studies in any previous low state. It could be mighty interesting. 2. V1294 Tau = "Tau 2". We once observed it with TWO superhumps - positive and negative. But the signals were too weak to be 100% certain. Still well placed in December, and at +6 degrees, available to both hemispheres. 3. IM Eri. Great southern target, and also for intrepid northerners (-20). At 11.7, great target for small scopes or bright skies. Another SW Sexer (like 1 and 2). 4. ES Cet. We need timings of its 9 minute signal. Fun target with such a clean signal. 5. V1159 Ori and DI Ma. Keep the faith - they're going well! joe From jop at astro.columbia.edu Tue Dec 11 13:29:16 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 11 Dec 2012 13:29:16 -0500 Subject: (cba:news) t pyx and sdss0755+1435 Message-ID: <50C77B7C.90006@astro.columbia.edu> Two stars I forgot to mention. 1. SDSS J0755+1435. Vital to get snapshot (preferably V) magnitudes over the next two nights, to compare with HST data (and to green-light the observations). 2. T Pyx. How could I? The star is back, the orbital modulation is back, and the period has changed. A lot. High-priority target for long time series! joe