From jop at astro.columbia.edu Sun Nov 9 04:49:51 2014 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 09 Nov 2014 04:49:51 -0500 Subject: (cba:news) ATel 6676, and other targets In-Reply-To: <20141109071820.6995516F83B1@sedna.astro.columbia.edu> References: <20141109071820.6995516F83B1@sedna.astro.columbia.edu> Message-ID: <545F38BF.60008@astro.columbia.edu> Dear CBAers, The hits just keep on rolling, for the ASAS-SN discoveries. This one is very bright and pretty likely (not certain, confirmation needed) to be a CV. Somewhat out of season, so try for as long as possible - and hopefully with Europe-USA handoffs. Midterm exams, my New York conference (cbastro.org/workshop/), and grant applications have been taking their toll. Not done yet, but let's update the night-sky hits: Stars important to cover before they say goodbye for the year: V Sge. Very little data this year. We need eclipse timings. DQ Her. Timings of the 71 s pulsation. So to contribute on this guy, you need a total cycle time <25 s. Aside from that stringent demand, it's an easy and rewarding target. Make sure your absolute timekeeping is accurate! V455 And. Mainly timings of the 68/34 s pulsation. Total cycle time <20 s needed. Much more demanding than DQ Her... but better placed in the sky. V1101 Aql. Whenever it's faint (>14,7 or so). Other targets. ASASSN-14ei still refuses to die. Gordon Myers, Bob Rea, and Josch Hambsch are gunning for it every night, and it continues to flash its lovely periodic (probably a superhump). Let's keep the faith. Those helium stars sure do love their echo outbursts! Time to quit on V592 Cas. Enrique has studied all the data coming in - quite a lot - and the star continues to flash a nice positive superhump and no other. So we've learned all there is to learn, apparently, on this star, this year. AH Men, AQ Men, IM Eri. Time to start the season up for all these stars. They have done yeoman service for us in the past, and we've published detections of negative superhumps in each (that is, *positive* detections of negative superhumps). Now let's dig deeper: are the periodic signals always there? just how good are they in maintaining phase over long intervals? AQ Men is also an eclipser, and I think the eclipse depths depend on precession phase - cute! But the evidence from previous data is ambiguous - let's nail it down. Note AH Men has a close companion of similar brightness; you might have to include it in the "aperture" - but however you decide to observe it, do it consistently. (Default, until someone tells me this is a bad idea, is to observe unfiltered and include the companion in the aperture. I need help with this, though; it's hard to judge when you're a thousand miles from telescopes.) BTW, northerners don't be bashful re IM Eri: a bright star at -20 degrees, that's manageable. And T Pyx - he's baaaacckk! Time to start up the season. The properties of the orbital signal get more fascinating with each passing month, it seems... if that's even possible. New hypothesis: many CVs end their lives as a T Pyx, in a series of uncontrolled, repeated nova outbursts - evaporating the secondary in a million years. We only see one in the sky (the biggest mystery of all: just one, and it's 4.5 kpc away!) because a million years is so short, just 0.01% of a CV's total lifetime. We have to keep after this star. Unfiltered, and keep the same comparison star. FS Aurigae: start up the season! WX Ari: Let's keep going, for sure. And maybe you can go check on novalikes with orbital periods below 4.4 hours - are there any others in low states? (Check Ritter catalog for the list.) We like these stars all the time, but *especially* when they're in low states. joe -------- Original Message -------- Return-Path: ------------------------------------------------------------------------------ ------------------------------------------------------------------------------ The Astronomer's Telegram http://www.astronomerstelegram.org ============================================================================== ATEL #6676 ATEL #6676 Title: ASAS-SN Discovery of a Very Bright Optical Transient Author: B. J. Shappee (Hubble Fellow, Carnegie Observatories), K. Z. Stanek, A. B. Davis, G. Simonian, T. W.-S. Holoien, C. S. Kochanek, U. Basu, J. F. Beacom (Ohio State), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), J. Brimacombe (Coral Towers Observatory), D. Szczygiel, G. Pojmanski (Warsaw University Observatory) Queries: shappee at astronomy.ohio-state.edu Posted: 9 Nov 2014; 07:15 UT Subjects:Optical, Cataclysmic Variable, Transient During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the quadruple 14-cm "Brutus" telescope in Haleakala, Hawaii, we discovered a new transient source: Object RA (J2000) DEC (J2000) Disc. UT Date Disc. V mag ASASSN-14jv 18:53:28.87 +42:03:43.59 2014 Nov 9.19 11.3 ASASSN-14jv was present in two images obtained on 2014 Nov 9 but undetected (V>15.7) on 2014-11-07.2 and earlier. There is a nearby blue source in the Kepler Input Catalog (18:53:28.814, +42:03:43.57), with g=19.1, r=19.4, and i=19.6, 0.6" away from our nominal position in the discovery image (ASAS-SN image scale is 7.5"/pixel). Additionally, there is also a GALEX source 0.021' away from our nominal position. ASASSN-14jv is most likely a large-amplitude CV outburst, caught very early. Follow-up observations are encouraged. We thank LCOGT and its staff for their continued support of ASAS-SN. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients. ------------------------------------------------------------------------------ ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/