From jop at astro.columbia.edu Thu Apr 14 16:24:41 2016 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 14 Apr 2016 16:24:41 -0400 Subject: (cba:news) (cba:chat) ASASSN-16eg In-Reply-To: <8E9D347D-9EAB-4B75-87CA-F420415A8F6B@gmail.com> References: <8E9D347D-9EAB-4B75-87CA-F420415A8F6B@gmail.com> Message-ID: <570FFC89.6060102@astro.columbia.edu> Wow, this is great stuff! WZ Sge out at that long period are GOLD! Keep up the great work. Much longer message coming tonight or tomorrow. joe p On 4/14/2016 2:41 PM, Enrique de Miguel wrote: > Dear all, > > You are all getting nice data sets on this new object. Bravo! > > Not much time now for a much detailed analysis, but all indicates > that this is a WZ Sge star (clear double-humped superhumps) > but with a relatively long period, 0.07548(3) d -actually, one of > longest of the WZ Sge family. Could this object be one of those > elusive period bouncers -old objects that have evolved past the > minimum of the Porb distribution? For this, we'll need to estimate > the mass ratio, something that one can infer after measuring > the excess superhump period. In other words, keep the pressure > on this target ..... > > Enrique > ____________________________________________________________ > Center for Backyard Astrophysics (CBA) mailing lists > https://cbastro.org/communications/mailing-lists/ > ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/ From jop at astro.columbia.edu Tue Apr 26 00:04:52 2016 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 26 Apr 2016 00:04:52 -0400 Subject: (cba:news) stars for april-may Message-ID: <571EE8E4.8060300@astro.columbia.edu> Sent in several formats. BTW, GP CVn might be a very good target, if the present outburst is a super. Nice evening target for borealites. joe -------------- next part -------------- A non-text attachment was scrubbed... Name: cba42516.pdf Type: application/pdf Size: 31808 bytes Desc: not available URL: -------------- next part -------------- A non-text attachment was scrubbed... Name: cba42516.odt Type: application/vnd.oasis.opendocument.text Size: 26159 bytes Desc: not available URL: -------------- next part -------------- April 25, 2016. Dear CBAers, Some great coverage on ASASSN-16eg, the dwarf nova of the year. We're done with it now, unless it does something unexpected. Likewise for RZ LMi; it appears to have once again refused to surrender its precise orbital period, although I haven't yet finished analysis of it. V803 Cen is a harder case. The coverage during the sustained superoutburst phase was excellent, and we've tracked it through most of its fast up-and- down excursions ("echo outbursts"). But the latter is a lot less interesting, since the superhumps themselves are gone or very muted. A second full (super)outburst would be great - and isn't too much to hope for, since it's due in a couple of weeks and only lasts 4-5 days. Let's keep our eyes peeled, though full time series are not important now. I was going to call for a full campaign on NR TrA, but then Gordon sent in 7 long nights on it - which fully define the orbital light curve (and therefore entirely takes NR TrA off the list). That was easy. A word about this project - the long-term "old nova project". We'd like to track the evolution of nova orbital light curves, over the first few decades after outburst. The most interesting interval is the first few years, so even very recent novae (say 1-3 years) are eligible. Most novae flash orbital light curves, and most show a very characteristic light curve, suggesting heating of the secondary - a double-sinusoid with an apparent eclipse. In theory, the evolution of the "eclipse" and the double wave allows deduction of the changing pattern of heating in the binary... and that might even allow us to track the cooling of the white dwarf, decades after eruption. (We've done a few stars since the 1990s, so have a lot of data on this.) Now that Sgr-Sco is wheeling back in the morning sky, it should be a great time of year. But unfortunately, field crowding and sometimes plain old lack of effort have resulted in many Sgr-Sco novae being not securely identified at quiescence. You australites might have your own favorite one to go after; my two southern suggestions are U Sco (18th mag - approach with caution) and V4743 Sgr (also a DQ Her star). Need long time series, because we're going after the orbital light curves. The equatorial/northern stars in this category are V1494 Aql, V1974 Cyg, and V476 Cyg. The first is especially tempting, since it has a true eclipse and can be observed north and south. More seasonal eclipsers, not novae but hot CVs with similar light curves: WX Cen and V617 Sgr. In these cases we just want to time the eclipses (tracking Pdot). Two northern novalikes appear to be in low states: MV Lyr and LN UMa. These don't happen often, and none have been targets of time-series photometry. Great choices if they're not too faint! And two southern DQs are good for coverage now: RX1654-19 and V1223 Sgr. And marginally also AO Psc and FO Aqr. Whew, that's a lot... and Enrique, who keeps up a much sharper eye on these things than me, may want to add/clarify. Happy observing! joe p p.s. Oops. Another equatorial star, very much in season, is V406 Vir (SDSS1238-03). Very strange 8-hour quasiperiod in this star, of unknown origin. It would be great to have some understanding of this signal. Sitting astride the equator, it offers us the opportunity to acquire really long runs. -------------- next part -------------- ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/