Saturday, March 10, 2012

ESO Conference: Observing Planetary Systems II

I spent 4 days this past week attending the European Southern Observatory (ESO) conference "Observing Planetary Systems II". This post is a brief summary of what went on and my thoughts during the conference.

The conference was fairly small- about 100 people or so. Compare that to the American Astronomical Society (AAS) meetings where you can have easily more than 1,000 astronomers show up. This makes finding people much easier and you interact with the same folks continuously. An additional difference is that things are much more focused: all the talks and poster were on planet, planet formation, observations (AO, infrared, sub-mm), models, disks, and all topics in between. That's a cool set of topics and everyone seems to be working on the same thing so you get some useful discussions.

There was also a small poster session. Because of so few posters, though, by day 2 one has really seen them all. Still, I tried to hang out near mine and approach people who seemed to be reading it. I'm always shy about doing so, but I try not to let that stop me. It helps that the astronomers here were cool folk and are interested in this type of research. My poster was about debris disks in binary systems. The main goal is to advance our understanding on planet formation and evolution in binary star systems.

Day 1
Some good talks, most notably the invited talks. These were longer and more big-picture type talks. As a big-picture type person I totally appreciate these overview presentations. The break-up of topics was well done. The first day focused on disks and the first few million years of planet formation, and indeed all the topics dealt with these topics.

We also got to see (again, after AAS) the Fomalhaut ALMA data. I was told by the speaker this should be submitted later this week so we may see the data soon. I'll try to write a brief post on those results when they come out.

I'm never been a big coffee person, but on conferences like these I do consume quite a bit. You really need it to stay alert after hearing 4 back-to-back talks or after 8 talks or after 14, though by then you should probably just go home as 14 was the number of talks for the first day.

Day 2
Met some more cool people and saw some nice talks, especially about efforts in the direct imaging of exoplanets, which was the main topic of the day (along with planet models). I had crafted an origami-style business card holder the prior night (thanks to this video) so I could put my brand new business cards by my poster. I got a chance to describe my research to a few more people today too.

By the end of the day I had information overload. At a larger conference I wouldn't feel too bad about skipping out on a few talks and just resting, but I wanted to hit all the talks. That's the problem with such a focused conference: everything ties together and, if you like seeing the big-picture as I do, then you want to see it all.

My poster! Pretty much recycled from AAS. The QR code points to a page on my professional website describing the research in a bit more detail along with providing links to the poster, the paper, and my other research.

Day 3
Same as the prior days in terms of talks (some good, some so-so) and meeting people. A lot of talks about our solar system; Dave Jewitt (UCLA) gave a really interesting talk on ice in the solar system. I learned a lot. Like Hilke Schlichting (also UCLA), he took the time to work out some math on the board. Is that a UCLA thing? I did my graduate studies there and took a class called Order of Magnitude Astrophysics (OoMA), which involved going up to the board and solving astronomy-related questions on the fly. This was very much like that. Both times worked very well, in my opinion.

After lunch, we switched out from the solar system and ices and into planetary atmospheres. This isn't my field of expertise and I'd already heard some of the topics back in the US among my UCLA colleagues.

Day 4
I missed the first half of the day since I was running some errands. This is related to something really cool I'll be doing at the end of the month so expect some awesome pictures then. This meant, though, that I missed the talks on biomarkers (signatures of life on other worlds), which should have been interesting. Coincidentally, one of the talks was, and I kid you not, by John Carter on Mars. I did a double take when reading the schedule given the fact that the movie was coming out that day here in Chile and it concerns a man of the same name (John Carter) and Mars. I honestly hope he had some good jokes or humor regarding the connection between them in his talk.

The afternoon session focused on some of the future instruments and surveys coming online that will help find planets. The talks were a bit diverse and I think this was mostly just the overflow of those talks that didn't quite fit anywhere else. Still, there were some interesting talks.

The conference room while at a coffee break.

Final Thoughts
Overall, the conference was good. I enjoyed most the review talks, especially those about topics only tangentially related to what I do. I learned a lot of interesting facts and concepts in these. The individual topic talks were sometimes good, but it depended a lot on the speaker. A few speakers were clearly enthusiastic whereas others just looked tired. The talks will eventually be posted on the conference website in case you want to check them out.

While there weren't a lot of brand new results, there were still many interesting facts/concepts that I either didn't know or didn't appreciate before. Here are a few that stood out:

  • The inward migration of Neptune is believed to have stirred up the planetesimal population in the Kuiper belt preventing the run-away growth phase and causing collisions to be destructive. This prevented any other large planets from forming out there. 
  • Angular differential imaging (ADI), a technique used to search for faint planets around nearby stars, can significantly affect extended structures, such as disks. Potential effects include producing warps, overly bright disk midplanes, or cavities in the disk.
  • A giant planet survey with the Gemini NICI imager suggests that less than 10% of solar type stars have giant planets of more than 4 times Jupiter's mass at separations larger than 10 AU.
  • Single power law models for planet characteristics among radial velocity detected planets cannot be extended to the directly imaged planets. Our understanding is still incomplete and/or these two techniques probe different populations of planets.
  • The Kozai mechanism, in which a 3rd object in a system (say a distant secondary star or planet) causes the eccentricity and inclination of the 2nd object (say a planet around the primary star) to oscillate, also works in the case of an inclined planet crossing a disk. Dynamical friction will dampen the inclination oscillations, though the disk can dissipate before it is fully damped.
  • The ~1m/s limit on radial velocity planet searches is driven by intrinsic stellar phenomena. Data analysis techniques, such as binning the data, can be used to get higher precisions.
  • There's both crystalline ice (like the type on your freezer) and amorphous ice, where the molecules are randomly arranged. Amorphous ice can very quickly, and explosively if it has trapped gases, convert to crystalline ice if it has enough energy or it gets warm enough. At 100 Kelvin (-173 Celsius, -280 Fahrenheit), the transformation takes only a millisecond.
  • At any given time, there are 1-2 1-meter size 'mini-Moons' sharing the Earth's orbit for a period of a few months. Much larger mini-Moons, say 100-meters, only share the orbit once every 100,000 years. These larger objects would be visible to the naked eye. Note that these mini-Moons are not truly bound to the Earth and are just passing through.

 The best quote from the conference:
Planets are more exciting than galaxies.
  - Dave Jewitt


  1. Awesome recap! :) Love the John Carter coincidence and Dave Jewitt quote.

  2. I also liked the discussion on the amount of cows on Mars, and by the stiff upper limit of 2 cows / km^2