Wild Stars- Day Four

Now that it is done, I am feeling a mix of relief and sadness. Relief- because four days of intensive research results presented session after session is like cramming a semester's worth of astronomy into your brain in four days. Sadness- because I could take maybe one more day, just to finish meeting and talking with some of the people I really wanted to talk to one on one. There just wasn't enough time. I think this was the most worthwhile, well-organized and relevant conference I have ever attended.

I'm not knocking any of the organizers of variable star meetings I've been to in the past, but this was all about CVs, all the rock stars of CV research were here, and I had back stage passes. It was frakkin' cool. The last day of the conference was all about things I am interested in- TOADs, Recurrent Novae and Classical Novae.

The talks of the day were also book-ended by two impressive astronomers from Japan's VSNET, Daisaku Nogami and Izumi Hachisu.

First thing in the morning session Daisaku Nogami presented impressive results of the superoutburst evolution of three very interesting CVs- WZ Sge, GW Lib and V455 And. These are three of the most significant outbursts of dwarf novae in the last couple years and Nogami had it all nailed down. The following talks on GW Lib and V455 And were almost redundant after the impressive amount of optical photometric and spectroscopic information Daisaku presented first thing in the morning.

The last talk of the morning session was about the source of negative superhumps, by Michele Montgomery. I had the pleasure of meeting her and talking for an hour or so Tuesday night, at the NOAO reception. She is an excellent presenter and had a great talk, chock full of teasers about her upcoming publication.

You just have to be intrigued by a woman who can teach you all about the minimum accretion disk tilt needed to generate negative superhumps in light curves, the parameters that affect negative superhump signal strength, and the location in the disk that contributes to this phenomena. That is sexy stuff!

Not to dismiss the other presenters who talked about classical novae and recurrent novae after lunch, but Brad Schaefer stole the show with his talk. Brad does not need a microphone to be heard in a room of 200 people. He is enthusiastic and knowledgeable about his topic, recurrent novae, and he knows how to work a room.

Some of the most exciting news from Brad were previously undiscovered eruptions of RN in past years. He and his graduate assistant relentlessly scoured all the archival data in the world to find plates and observations of recurrent novae outbursts. They found three eruptions of U Sco (1917, 1945, 1969) RS Oph in 1907, V2487 Oph in 1900 and CI Aql in 1941.

From these intensive searches, and modeling the results, Brad is able to make some bold predictions about the timing of future eruptions. In the next decade he predicts no less than five recurrent novae eruptions- V2487 Oph, V394 CrA, V745 Sco V3890 Sgr and the one he is most excited about U Sco. U Sco is predicted to erupt in 2009.3, which is RIGHT NOW!

After lunch we were shown amazing results of x-ray observations of recurrent novae and novae. There is a lot of interest in novae eruptions by professionals, more than I realized. What's more, they are making x-ray observations of these objects months and years after the initial outburst in an attempt to observe just when the accretion disk reforms and accretion begins again and what happens at this phase of the outburst.

From this I realized, amateurs need to follow many of these objects for much longer than we typically do as best we can. The AAVSO light curves sort of peter out after six months or so, and rarely is there much follow-up when a star reappears from solar conjunction. It's like we've all forgotten about them and moved on to the next big thing. Unfortunately, this is about the time they become really interesting to professionals, and from what I was seeing there may be some very interesting observational phenomena we are totally missing, like sudden rebrightenings of the systems or flickering. Amateur CV sleuths take note!

One of the final talks of the conference was from Izumi Hachisu. He presented the methodology and results of his search for a relationship between the t3 time of decay (the 3 magnitude decay time from optical maximum) and the turn-on and turn-off times of supersoft x-ray emission. He presented detailed light curve analysis of classical novae detected in x-rays, and proposed best fit models that reproduce the optical and supersoft x-ray observations. If all that sounds impressive, you're right, it was. The fact that most of the data was collected with relatively small telescopes makes it that much more impressive.

That's about all I can dig out of my CV overloaded memory and notes at this point. I'm going to let this all digest for a day or two and write a summary review. I know I am looking forward to the next CV conference, which is planned for 2010 in Kyoto, Japan!

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