From jop at astro.columbia.edu Sat Mar 3 10:21:56 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Sat, 03 Mar 2012 10:21:56 -0500 Subject: (cba:news) CR Boo in superoutburst Message-ID: <4F523714.4000806@astro.columbia.edu> Hi CBAers, Tom Krajci found CR Boo in superoutburst last night, and superhumping away. Though it's slightly early in the Boo observing season, it's a great opportunity to get an early start, and at +8 degrees dec, the star is available for all hemispheres. Fire away! Tom, could you send full information on the comparison star? Just to carve out some room in the menu, the BK Lyn soldiers can take a break. It's great to see those large-amplitude humps night after night... and indeed, this year's BK Lyn coverage will be re-writing some books - but the 60 days have *perhaps* taught us everything we're going to learn. In the next two days I'll evaluate several of the other stars on our menu: CP Pup, DW UMa, BH Lyn, at least. Some of the others will take a little longer - you guys have been sending a lot of data! joe From jop at astro.columbia.edu Mon Mar 5 07:58:23 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 05 Mar 2012 07:58:23 -0500 Subject: (cba:news) V393 Hya, CP Pup, CR Boo, BH Lyn, BK Lyn, ER UMa, V1159 Ori Message-ID: <4F54B86F.8090700@astro.columbia.edu> From jop at astro.columbia.edu Mon Mar 5 08:07:40 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Mon, 05 Mar 2012 08:07:40 -0500 Subject: (cba:news) sigh... Message-ID: <4F54BA9C.3070607@astro.columbia.edu> oops, a few minutes ago my long message on campaign stars was rendered blank - for no known reason. Maybe one errant twitch of the finger. I'll reconstruct during the day, and from now on send as an attachment (which will prevent these occurrences). I'll send as .txt and .doc, and hope that everyone can read these. The very, very short version: delete DW UMa, CP Pup; heavily promote V393 Hya, BH Lyn, CR Boo. Middle ground on ER UMa, BK Lyn, V1159 Ori. joe From jop at astro.columbia.edu Sat Mar 10 05:12:20 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Sat, 10 Mar 2012 05:12:20 -0500 Subject: (cba:news) BK Lyn needs love too... Message-ID: <4F5B2904.6020800@astro.columbia.edu> Dear CBAers, Oops, got distracted by school biz. I think I went too far in suggesting some back-off from BK Lyn. It seems to be the star of 2012, and I was just musing that it could survive with somewhat less attention. The result was no data at all for about a week... and since the star is showing some very unusual behavior this year (the brightest, and faintest, ever), it has a good claim to be back on your A-list (or at least B). I peer anxiously at my inbox for BK Lyn data every day. I'm still studying BH Lyn (as is Enrique, more carefully than me I'm sure). Jury is still out. Superhumps are certainly much weaker than BK Lyn. The CR Boo and ER UMa superoutbursts seem to be over, but these stars are almost certain to maintain their superhumps long afterwards - "aftershocks", or superhump inertia. It's our job to document this. So these stars should remain on your A-list. CR Boo especially - with such a short Porb and with so few decently bright members of its class (the AM CVn class), we should strive mightily to trace its behavior in detail all the way to the next super, at least. Mighty important star. I did want to take V1193 Ori (too dead) and CP Pup (season over, sufficient data in hand) off the list. I'm skeptical about V1159 Ori; it's a very suitable star for us and I've been delinquent in not mentioning it for 15+ years... but it's just too late in the season for us to get the needed dense coverage. If you only have a few evening hours available, some better targets might be BG CMi, PQ Gem, Swift J0732-13, RX0636+35, and RX0704+26. All stars not much observed this year. The last one has a *sensational* light curve - run the exposures 5 times faster than you think you can get away with for this 17th mag star. (Nearly everyone looks at the light curve and thinks it's noise; it's actually a very fast and very large pulsation). joe From jop at astro.columbia.edu Fri Mar 16 14:54:11 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Fri, 16 Mar 2012 14:54:11 -0400 Subject: (cba:news) stars in progress Message-ID: <4F638C53.7040603@astro.columbia.edu> Dear CBAers, Most of the northern targets we're following are going great guns: BK Lyn and ER UMa are re-writing record books (and we're rewriting them too, for diligence of tracking). BH Lyn has a weaker signal, but is starting to define itself through the fog. All three stars show evidence (the first two are obvious) of simultaneous positive and negative superhumps. We've seen a few examples of this before, but with great coverage can trace how the two interact - and to what extent they participate in eruptions. RZ LMi is also well worth following. We don't have much data yet this year, but I expect it to be very rewarding. I'm inclined to take DW UMa off the list. Humps this year, other than orbital, are weak - hard to distinguish amid the large orbital modulation. And in its place I propose LN UMa = "UMa 7". Possibly a similar star, and one we have little acquaintance with (just one season). And V355 UMa = SDSS1339+48. The latter is quite faint, about 17, but will be fascinating to watch for its post-eruption behavior. In the south, we've discontinued CP Pup (seasonal, plus an embarrassment of riches) and V393 Hya (sigh, just not doing anything this year). In their place I suggest SW Sex, plus the helium stars CR Boo and V803 Cen. Especially CR Boo - for all hemispheres. I hope to make this one the centerpiece of our March->May observing. joe P.S. Just registered and sent in a BK Lyn abstract for the SAS meeting - where I hope to see a bunch of you! (I attach the abstract) -------------- next part -------------- A non-text attachment was scrubbed... Name: bklynabs.odt Type: application/vnd.oasis.opendocument.text Size: 17115 bytes Desc: not available URL: -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: bklynabs.txt URL: From jop at astro.columbia.edu Sun Mar 18 06:48:03 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Sun, 18 Mar 2012 06:48:03 -0400 Subject: (cba:news) BK Lyn erupting again? Message-ID: <4F65BD63.7030302@astro.columbia.edu> Hi CBAers, Anyone able to observe BK Lyn tonight? Yesterday's data from Josch Hambsch and Joe Ulowetz suggested that this star may be going into outburst (again??). This is fascinating to me because it's a novalike variable that has not previously shown outbursts - or at least outbursts that looked like dwarf-nova events. One popped up early in this season's coverage - just following the star's dropping to the faintest state it has ever reached. That's true this time too (meaning yesterday - a slim basis for making this statement... but ptovocative). Excellent time-series photometry would be mighty nice! joe From jop at astro.columbia.edu Wed Mar 21 08:24:18 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 21 Mar 2012 08:24:18 -0400 Subject: (cba:news) Fwd: Fw: TOCP submission In-Reply-To: <7CB4009CBA4A4587AC5FE5058B532FF7@BobAcer> References: <7CB4009CBA4A4587AC5FE5058B532FF7@BobAcer> Message-ID: <4F69C872.5000407@astro.columbia.edu> Pretty exciting stuff, from Gianluca Masi. Great object for time-series photometry! Don't forget about BK Lyn, which is blazing a path to glory this year... but some of the other targets could take a mild vacation... joe -----Original Message----- From: cbattcp at eps.harvard.edu Sent: Wednesday, March 21, 2012 9:37 AM To: bob at antelopehillsobservatory.org Subject: TOCP submission Central Bureau for Astronomical Telegrams Transient Object Confirmation Page Report TOCP Designation: TCP J08461690+3115554 Observation Date: 2012 03 20.81 Remarks: I managed to do time-resolved photometry for 3 hours on this OT, before the clouds forced me to stop. I remotely used the photometric 14"@f/8.7 unit part of the Virtual Telescope Project, Ceccano, Italy . The OT (found at mag. 17.3) is clearly superhumping, with an amplitude of 0.5 mags, so being a SU UMa dwarf nova in superoutburst,. Also, it is showing sharp, >2-mag deep eclipses, with a duration around 25-30 minutes. A search for the superhump period provided a candidate of 2.27 hours, into the period gap. The LC is available here: http://virtualtelescope.bellatrixobservatory.org/TCP_J08461690_3115554_20mar2012.jpg From jop at astro.columbia.edu Wed Mar 28 08:04:57 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Wed, 28 Mar 2012 08:04:57 -0400 Subject: (cba:news) CR Boo! Message-ID: <4F72FE69.1000104@astro.columbia.edu> Josch Hambsch's observation revealed CR Boo at 17.5 last night. We've been waiting for this! Since it's equatorial and transiting near midnight, the star is pretty well placed for everyone - and it would be awfully nice to jump on this bashful star and obtain time series before it leaves this rare low state. The relevant period is ~25 minutes, but there's not much known about what will show up... so probably you can afford longish integrations - but not too long. Most people should observe unfiltered, but if you have a (relatively) big telescope and very good night, some filtered photometry. And if you have any opportunity to obtain spectroscopy (on a 1+ m telescope), do it! The only time we ever caught CR Boo faint, we obtained a super-strange spectrum - it looked like a G star with helium-2 emission. That's strange enough to be a good candidate for a mistake; but we thought hard about it, and couldn't figure out any mistake we made. We haven't been watching *extremely* closely... but for me, it's been a 20-year wait. joe From jop at astro.columbia.edu Thu Mar 29 04:15:18 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 29 Mar 2012 04:15:18 -0400 Subject: (cba:news) (cba:chat) BK Lyn mag 14.2... also DI UMa, RZ LMi, and IX Dra In-Reply-To: References: Message-ID: <4F741A16.4090607@astro.columbia.edu> Hi Joe, Yes, that's very likely it - it's right on schedule. Also, 14.0 is about right for a super. But all that is based on this year. Seems to be a bona fide dwarf nova this year - but it has been a novalike variable for 20 years, and we've been very persistent at looking too. In fact, my guess is that it has been a novalike variable for 2000 years... or more precisely, between 1904 and 1910 years (there's a good chance it was a classical nova in 101 AD). Nova->novalike->dwarf nova: the decathlete of eruptive variables. Those of you observing this star have probably gotten used to those beautiful huge waves in the star at V~16 - the negative superhumps. They're nearly gone at V=14. How come? Supposedly, CVs should *grow* superhumps in superoutbursts, not suppress them. Au contraire, sort of. *Negative* superhumps (by definition P Would this be considered a super outburst? It's brighter than I've seen it > before. > > -Joe U. > > > > ____________________________________________________________ > Center for Backyard Astrophysics (CBA) mailing lists > https://cbastro.org/communications/mailing-lists/ From jop at astro.columbia.edu Thu Mar 29 13:00:02 2012 From: jop at astro.columbia.edu (Joe Patterson) Date: Thu, 29 Mar 2012 13:00:02 -0400 Subject: (cba:news) Fwd: SS UMi In-Reply-To: <9C947B6B-0225-4B49-A722-D92D8C9BEB85@gmail.com> References: <9C947B6B-0225-4B49-A722-D92D8C9BEB85@gmail.com> Message-ID: <4F749512.2060908@astro.columbia.edu> Dear CBAers, I'm forwarding this note from Enrique. I hadn't gotten around to studying the SS UMi data - but it may well be another member of that club. Good target for morning photometry, especially from the USA. joe Joe, SS UMi could be another target to be added to the ER UMa-like target list you are suggesting. I started ~10-12 days ago to follow it and I'm getting the impression that a close look at this system will show similar behavior to that observed for ER UMa. I caught the star in super when I started (just by chance). Now that the super is over, it's at ~16.5. Faint, but doable, because the signal in this low state is of relatively large amplitude. I've got Josh, Tom, and David involved, but most of the data so far are coming for Euro longitudes, with the obvious aliasing. ~5 hour-long series from USA will be extremely helpful. If you think this target fits the CBA plan on ER UMa-like stars, would you mind calling for time series? I was on CR Boo yesterday night for several hours, but decided not to send the data (cloudy and data embarrassingly noisy). It was, as suggested by others, again around 16.8-17.0 mag. I will try some to get some B,V data, but that will have to wait a few days until the weather gets better. Enrique