From jop at astro.columbia.edu Thu Feb 2 14:05:28 2017 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 2 Feb 2017 14:05:28 -0500 Subject: (cba:news) CN Ori , CP Pup, and YZ Cnc Message-ID: Hi CBAers, CN Ori is heading back towards minimum, where its large-amplitude wave makes defining a period quite straightforward. Over an increasingly long interval, which is our goal (as well as to test whether the wave at maximum is the same phenomenon). So some long light curves right now would be great. The ones at max are slightly less useful. CP Pup. Be still, my beating heart. I've lusted after this star for a few years. Its large-amplitude photometric wave occurs at a period a few percent longer than Porb. in our 1995 paper (me and Warner 1995) we said "probably 2%", which would be basically a normal superhump, nothing particularly special. But 2-3 years ago, our campaign data strongly preferred a number near 7%. The difference may seem small, but it's "astronomically" significant - it would be quite inconsistent with the usual "3:1 resonance" explanation for superhumps. The signal is of large amplitude but *poor* coherence - so much so that it's hard to unambiguously count cycles from night to night. We absolutely need 2-longitude coverage, and really a 3rd is needed to be sure (and in fact a *streak* of a few consecutive nights of 3-longitude coverage). For you southerners down there, consider making this star a high-priority target. 2 versus 7... it's one or the other (they differ by 1 cycle/day over one day's span), and quite a bit rides on the answer. It's about mag 15.5, nothing too challenging. YZ Cnc. Getting close to the "expected" rise to a normal max, so now's the time to watch carefully... and compare to the energing AAVSO lightcurve to evaluate whether what you see is a steady rise, or just some more eeratic variability. Notify if it looks interesting! That's three of our targets. More later. joe ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/ From jop at astro.columbia.edu Fri Feb 10 18:39:12 2017 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 10 Feb 2017 18:39:12 -0500 Subject: (cba:news) Fwd: (cba:chat) YZ Cnc -- The Hunt Is Back On! In-Reply-To: <1ACF80922713204BA703D6242931D16354C6BFE8@SRV00048.soton.ac.uk> References: <1ACF80922713204BA703D6242931D16354C6BFE8@SRV00048.soton.ac.uk> Message-ID: <4aacd025-2fb0-bbbe-d2e7-d65734530005@astro.columbia.edu> Just in case some of you are on cba-news but not-chat... Joe Ulowetz had it around 14.7 (quiescence) last night. Also keep the faith on CN Ori; the preliminary results are definitely interesting, but need another 2 weeks of coverage to nail down. It needs pretty long nightly coverage, since the period is near 4 hours. joe -------- Forwarded Message -------- Subject: (cba:chat) YZ Cnc -- The Hunt Is Back On! Date: Fri, 10 Feb 2017 22:22:45 +0000 From: Knigge C. Reply-To: cba-chat at cbastro.org To: cba-chat at cbastro.org Hi all, just a reminder that Chandra should now be able to trigger on YZ Cnc again, so I am planning to trigger on the next outburst that we catch fast enough and that Chandra headquarters think they can move on fast enough. It looks to me like the next rise should not be far off, so if you can once again get dense monitoring of the system, upload to the AAVSO, and notify me personally when it looks like we're heading up, I would hugely appreciate it! Thanks! Christian -- =================================================== Professor Christian Knigge Physics & Astronomy University of Southampton Southampton SO17 1BJ ==================================================== ____________________________________________________________ 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 Sun Feb 12 07:26:44 2017 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 12 Feb 2017 07:26:44 -0500 Subject: (cba:news) Fwd: [vsnet-outburst 20475] ASASSN-15kf: AM CVn-type, likely superoutburst In-Reply-To: References: Message-ID: Nice! Great early-morning target for the australites (and Floridians) among us. Meanwhile, the dragnet for YZ Cnc goes on. Keep the faith on CN Ori too. joe -------- Forwarded Message -------- Subject: [vsnet-outburst 20475] ASASSN-15kf: AM CVn-type, likely superoutburst Date: Sun, 12 Feb 2017 20:57:25 +0900 From: Keisuke Isogai To: vsnet-alert at ooruri.kusastro.kyoto-u.ac.jp , vsnet-outburst at ooruri.kusastro.kyoto-u.ac.jp ASASSN-15kf: AM CVn-type, likely superoutburst ASAS-SN detection. AM CVn-type. Observations are strongly encouraged. ASASSN-15kf 15:38:38.24 -30:35:49.7 17.98 2017/02/10 07:16 57794.30318999989 14.56 15.32 57590.13835 ASASSN-15kf 20170210.303 14.56V ASN ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/ From jop at astro.columbia.edu Mon Feb 13 09:26:56 2017 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 13 Feb 2017 09:26:56 -0500 Subject: (cba:news) CP Puppis, rest in peace (not) Message-ID: <893976b9-8d2d-0a48-5f29-5f2aa697cb92@astro.columbia.edu> Hi CBAers, I've completed analysis of the CP Pup data for the season. As was hinted at but not quite proved 3 years ago, the photometric period really is well separated - about 8% - from the spectroscopic (presumed orbital) period. Hallelujah. The instability in waveform and period shows that it cannot reside in the dynamical parts of the binary (the two stars), but must reside in the disk - the main source of light. Your basic superhump. Ever hear of such things? Me too. But 8% separation - not 2% as we thought 20 years ago, based on a 1-day alias - breaks all, or almost all, the rules. It indicates a very strong perturbation on the disk by the secondary. The most plausible way to get this is origin at the 2:1 resonance in the disk, not 3:1 as is customary for superhumpers. But very few disks are *big* enough to reach the 2:1 resonance; only for a very extreme mass ratio (probably M2/M1 less than around 0.05) can the disk extend that far. This probably indicates a secondary less than around 0.05 Mo. Kinda fascinating. There are very few classical novae of short Porb, although the great majority of CVs are of short Porb. This has always been troubling (to me; some others are strangely unruffled by it). CP Pup may guide us to a solution. But we're done for the year! joe ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/ From jop at astro.columbia.edu Mon Feb 13 09:32:45 2017 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 13 Feb 2017 09:32:45 -0500 Subject: (cba:news) CP Puppis, rest in peace (not) In-Reply-To: <893976b9-8d2d-0a48-5f29-5f2aa697cb92@astro.columbia.edu> References: <893976b9-8d2d-0a48-5f29-5f2aa697cb92@astro.columbia.edu> Message-ID: Oh... and a big shout-out to the stars of the campaign - Berto, Gordon, Josch, and Peter Nelson! On 2/13/2017 9:26 AM, Joe Patterson wrote: > Hi CBAers, > > I've completed analysis of the CP Pup data for the season. As was > hinted at but not quite proved 3 years ago, the photometric period > really is well separated - about 8% - from the spectroscopic (presumed > orbital) period. Hallelujah. The instability in waveform and period > shows that it cannot reside in the dynamcal parts of the binary (the > two stars), but must reside in the disk - the main source of light. > Your basic superhump. Ever hear of such things? > > Me too. But 8% separation - not 2% as we thought 20 years ago, based on > a 1-day alias - breaks all, or almost all, the rules. It indicates a > very strong perturbation on the disk by the secondary. The most > plausible way to get this is origin at the 2:1 resonance in the disk, > not 3:1 as is customary for superhumpers. But very few disks are *big* > enough to reach the 2:1 resonance; only for a very extreme mass ratio > (probably M2/M1 less than around 0.05) can the disk extend that far. > This probably indicates a secondary less than around 0.05 Mo. > > Kinda fascinating. There are very few classical novae of short Porb, > although the great majority of CVs are of short Porb. This has always > been troubling (to me; some others are strangely unruffled by it). CP > Pup may guide us to a solution. > > But we're done for the year! > > joe > ____________________________________________________________ > 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 Feb 14 00:09:48 2017 From: jop at astro.columbia.edu (Joe Patterson) Date: Tue, 14 Feb 2017 00:09:48 -0500 Subject: (cba:news) (cba:chat) YZ Cnc -- Chandra triggered -- continued dense monitoring requested... In-Reply-To: <1ACF80922713204BA703D6242931D16354C6FDBF@SRV00048.soton.ac.uk> References: <003c01d28523$ff2f86a0$fd8e93e0$@telenet.be>

<0252499a-0df6-39b8-f11f-a5f1496df62b@earthlink.net>

<130a8519-2434-c8db-bb17-341c7f9d09a9@astro.columbia.edu>

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<7cce35b4-7cc7-f922-d118-e3d41e59e25c@astro.columbia.edu> <1ACF80922713204BA703D6242931D16354C6FDBF@SRV00048.soton.ac.uk> Message-ID: <4b174ba4-25c0-aae7-3d9a-6bfa836188ae@astro.columbia.edu> Time to do YZ Cnc, north and south, tree to tree, for the next week! joe On 2/13/2017 10:59 PM, Knigge C. wrote: > Hi all, > > Chandra has been triggered -- the observation will be completed within > the next 3 days (likely within the next 2 or so). I think this gives us > as good a shot at catching plateau as we're going to get. > > If we could get really dense coverage of this entire outburst, that > would greatly help our cause! > > Thanks so much for all of your continued help with this! > > Cheers, > > Christian > > > > > On 13/02/17 19:17, Joe Patterson wrote: >> Wonderful. Definitely the eruption! Now... is Chandra ready to go? >> >> Needless to say, highest priority for us now. >> >> joe >> >> On 2/13/2017 10:03 PM, Geoff Stone wrote: >>> I make it 13.1 from California >>> >>> I'll keep on it for a while. >>> >>> On 2/13/2017 6:35 PM, Richard Sabo wrote: >>>> YZ CNC,2457798.60530,13.253, >>>> 0.015,V,NO,STD,000-BBP-199,19.253,000-BBP-235,18.915,1.39,na,X17257RB,Standard >>>> mag: C = 13.688 K = 13.354 >>>> Richard Sabo >>>> >>>> On Mon, Feb 13, 2017 at 6:39 PM, Geoff Stone >>> > wrote: >>>> >>>> I will try to check it at about 02:30 UTC >>>> >>>> On 2/13/2017 5:19 PM, Joe Patterson wrote: >>>> >>>> Pretty good chance this is the eruption. Can you or anyone >>>> else confirm - e.g. rising to 13.4? >>>> >>>> joe >>>> >>>> On 2/13/2017 7:41 PM, Joe Ulowetz wrote: >>>> >>>> I'm measuring YZ Cnc around 13.7 currently: >>>> >>>> YZ >>>> Cnc,2457798.5157523146 >>>> ,13.658,0.041,CV,NO,STD,000-BBP-218,15.177,000-BKT-688,16.113,1.578,NA,X17126ACK,na >>>> >>>> YZ >>>> Cnc,2457798.5166087961 >>>> ,13.639,0.040,CV,NOprovide >>>> ,STD,000-BBP-218,15.200,000-BKT-688,16.283,1.570,NA,X17126ACK,na >>>> YZ >>>> Cnc,2457798.5174652776 >>>> ,13.747,0.040,CV,NO,STD,000-BBP-218,15.130,000-BKT-688,16.365,1.563,NA,X17126ACK,na >>>> >>>> YZ >>>> Cnc,2457798.5183217591 >>>> ,13.756,0.043,CV,NO,STD,000-BBP-218,15.251,000-BKT-688,16.494,1.555,NA,X17126ACK,na >>>> >>>> YZ >>>> Cnc,2457798.5191782406,13.680,0.043,CV,NO,STD,000-BBP-218,15.259,000-BKT-688,16.498,1.548,NA,X17126ACK,na >>>> >>>> YZ >>>> Cnc,2457798.5200231480,13.719,0.039,CV,NO,STD,000-BBP-218,15.200,000-BKT-688,16.398,1.541,NA,X17126ACK,na >>>> >>>> YZ >>>> Cnc,2457798.5208796295 >>>> ,13.691,0.036,CV,NO,STD,000-BBP-218,15.140,000-BKT-688,16.458,1.534,NA,X17126ACK,na >>>> >>>> YZ >>>> Cnc,2457798.5217361110,13.677,0.035,CV,NO,STD,000-BBP-218,15.082,000-BKT-688,16.209,1.526,NA,X17126ACK,na >>>> >>>> YZ >>>> Cnc,2457798.5225925925 >>>> ,13.674,0.036,CV,NO,STD,000-BBP-218,15.094,000-BKT-688,16.267,1.519,NA,X17126ACK,na >>>> >>>> YZ >>>> Cnc,2457798.5234490740,13.708,0.034,CV,NO,STD,000-BBP-218,15.037,000-BKT-688,16.445,1.512,NA,X17126ACK,na >>>> >>>> >>>> -Joe U. >>>> >>>> >>>> >>>> ____________________________________________________________ >>>> 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/ >>>> >>>> >>>> >>>> ____________________________________________________________ >>>> 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/ >>> >>> >>> ____________________________________________________________ >>> 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/ >> > ____________________________________________________________ Center for Backyard Astrophysics (CBA) mailing lists https://cbastro.org/communications/mailing-lists/