Tuesday, January 7, 2014

AAS 223: Tuesday, January 7.

Round 2: lessons learned about how often to save my work after yesterday.

206.01 John Armstrong: The Applicability of Emerging Quantum Computing Capabilities to 
 Exo-Planet Research

Quantum computing generally more powerful than classical computers. Much faster at things like factoring large numbers, extracting signals from noise, many variable complex problems, and machine learning.
Man, I haven't seen quantum computing since undergrad. I'm definitely way out of date here.
Kepler-QC experiment compares classical vs quantum transit-finding algorithms. Apparently it did well.

206.02 Jon Jenkins: Likely Planet Candidates Identified by Machine Learning Applied to Four Years of Kepler Data

Kepler pipeline likened to I Love Lucy in a chocolate factory, more information than we know what to do with. Algorithm correctly identifies 96.4% of planet candidates, 89% of false positives. Basically, our machines are getting better. I for one welcome our new computer overlords.

207.02 Nikku Madhussudan: Constraints on Elemental Abundance Ratios in Hot Jupiter Atmospheres and Implications for Their Formation Conditions

Atmospheric H2O (and therefore C/O ratios) can be measured more easily for hot Jupiters than for giant planets in the solar system apparently. Of course, elemental abundances have consequences for planet formation. Where you form planets leads to different C/O ratios.
WASP-12b: C/O>1, atmosphere contains little water
WASP-19b: ruled out thermal inversion
WASP-33b: great for constraining C/O because of its obscene temperature. Definite thermal inversion.
Hot super-Earths are good candidates for measuring atmospheric composition.
Plug for more ground-based observations of these kinds of planets. For HST, hotter planets are better targets.

207.03 Knicole Colon: Characterizing Exoplanet Atmospheres with Narrow-Band Photometry
(Wooo! Someone I know!)

Why narrow-band photometry? Minimizes effects of Earth's atmosphere by probing narrow wavelength band. Observes multiple stars simultaneously. Tunable filters give you custom bandpasses, goof for probing Na and K lines, which produce narrow and strong lines in hot Jupiters.
XO-2b: observed in 5 bandpasses with 10m GTC/OSIRIS. Potassium definitely observed in atmosphere.
TrES-2b: same telescope, possible potassium absorption detection, odd detection around 778 nm. Nature uncertain.
GJ 1214b: narrow-band data at 2.1 microns. Atmosphere shown to be flat/featureless.

207.04: Joseph Harrington: Significance of Trends in Exoplanetary Atmospheres

Want model-indepentent atmospheric statistic, trying brightness temperature and equilibrium temperature. Odd stacking at T_eq around 2100K. Split data at 1850K and you get different slopes on your graph. Goodness of fit is pretty bad due to large amounts of scatter. Gotta admit, a lot of this is lost on me. Couldn't find any overarching conclusions to draw from this one.

207.05 Katja Poppenhaeger: Exoplanet transits in X-rays: a new observational window to the exoplanetary atmosphere
(X-rays? This should be interesting...)

Target: HD 189733, active K1 dwarf. Has wide M4 stellar companion (~100 AU). Planet b has 2.2 day period. HD 198733 is a bright star in X-rays (meaning you get 1 photon for every 10 seconds).
X-ray observations pick out stellar corona. Interestingly enough, center of transit is brighter because of corona angle you're able to look at.
Constrains atmosphere models of planet b.
Stars hosting planets with strong tidal effects are more active in X-rays than stars with weak tidal interactions with their planets.

207.06 Ming Zhao: A Survey of the Hottest Jupiter Atmospheres via Secondary Eclipses
(Wooo Penn State!)

Why do we care about the hottest Jupiters? Well hotter is better! (Awww yeah.) Best targets for thermal emission signatures, few condensates in atmosphere, disequilibrium chemistry limited. (Good, no one likes chemistry anyway.)
Observations with Palomar 200-inch H & K filters and Spitzer 3.6 & 4.5.
HAT 32A b: strong high altitude heating, not much recirculation
WASP48 b: moderate high altitude heating and recirculation

Photometry improved with better telescope guiding to constrain centroid drift AND a new detector calibration method to correct non-linear oddities present in IR detectors.
Next step: use defuser to stabilize and better distribute de-focused PSF (de-focus so you don't saturate your detector). Looks like it does a good job.
Should be able to detect more secondary eclipses with better observation techniques (should take us from 7 detections to ~30.

Last speaker's flight got cancelled. Poor Jean-Michel Desert. :(
Comparative exoplanetology sounded cool too...

219 Plenary Session Sally/Sarah? Dodson-Robinson: Giant Planets in Dusty Disks

How dust affects planet formation: provides planetary raw material and affects composition, thermal regulator of the disk, thermal emission can be an important dynamical indicator.
Consequences: Stellar photospheres can be used as tracers of grain nucleation, galactic evolution affects planetary formation.

Core accretion: bottom-up growth of giant planets. Bigger star means bigger disk means more raw material available for planet formation. More massive stars have higher planet incidence rates, as to more metal-rich planets. Means starting conditions are very important. Planet host stars tend to be more silicon-rich (statistically significant). Possible separation of populations around solar silicon abundance. No correlation seen with oxygen. Of course, oxygen is a major component of planets in various ways (rocks and water major oxygen carriers), so why doesn't it matter? Oxygen is not a limiting reagent in formation of any relevant minerals. Silicon, iron, magnesium matter more.

Do giant planets form from astrophysical cirrus clouds (formed from heterogeneous nucleation)? Is the ice line actually important at all for giant planet formation?

Dust and thermal regulation in protostellar disks.
Inner part of disk is "dead", unionized, doesn't interact with magnetic fields.
Opacity effects on stability: if disks are actually unstable, then we expect top-down giant planet formation. Disk sound speed an indicator of disk stability. If you have strong pressure support with high sound speeds, hard to collapse. If you can form planets via gravitational collapse, then the ice line in the disk doesn't actually matter. Jupiters may form in disks with different dust opacities than disks that form Neptunes.

Galactic planetary evolution: metallicity changes over generations of stars going supernova changes the means by which planets form. Back in the day, gravitational instability planets were likely more common. Gravitational instability also forms bigger planets, so planet size over time may have gotten smaller.

Dust as a dynamical signpost
Easy to see holes in the disk from dips in the SED at mid-IR wavelengths. Where do holes come from (especially ones that go out to 50 AU!)? Single planets cannot open such big holes in disks, even 10 M_J planets. Gap size scales as only M_planet^1/3.
Well how about multiple planets? Gaps formed by individual planets can overlap to make a big hole. Good match to what radio telescopes observe. IR picks up material in gaps. Tidal tails of material in gaps give you a way to move material into the star from the optically thick disk while still maintaining a mostly optically think hole. Observations of transitional disk around HD 142527 with ALMA and IR look like simulations. Gap-crossing stream maybe seen in HCO+.

Grain nucleation is a limiting step in planet building.
Grain composition and abundance affect planet formation mechanism.
Dust and gas configurations in transitional disks are best explained by multiple planets.

224.01 Christine O'Donnell: Science Education & Advocacy: Tools to Support Better Education Policies

Policy is everywhere. Funding, testing standards, REUs, promoting/aiding diversity in science, etc.
Advocacy is important for affecting policy. Speaker put together a collection of tools that can be useful in advocacy. Walkthroughs for effective advocacy strategies, one-page papers to leave with policymakers.
Working on women in science, planetarium funding. And she actually stuck to 5 minutes. Fantastic!

224.02 Denise Smith: Impact of NASA’s Astrophysics Education and Public Outreach Programs

Education forums organize individual programs such that they can work together. Allows access to/discussion of best practices & research. 10% of NASA's online traffic is on Hubblesite.org.
People are actually returning to outreach events (better to reach the same people repeatedly).
Chandra's workshop attendees are largely going into STEM fields in college. Materials reach 24 million people per year, inc 6 million students. .5 million teachers use materials from NASA.

224.03 Jim Manning: The ASP at 125: Advancing Science Literacy in an Age of Acceleration
(Happy birthday guys!)

ASP = Astronomical Society of the Pacific for those of you who don't know.
Goal: Advance scientific literacy through astronomy
Astronomy from the Ground Up, Cosmos in the Classroom, flying educators on SOFIA, etc all ASP programs.
ASP seeking private funding due to difficulties maintaining public funding.
Another talk that stayed in the time limit.

224.04 Gregory Schultz: Findings from a NASA SMD Survey of Two-Year College Faculty

Role of 2 year colleges in providing Earth and space science education to general workforce? Want to understand demographic makeup and views of STEM faculty at community colleges. 183 survey participants. Teaching breakdown: mostly earth science, followed by astronomy. Almost entirely non-majors in their classes (50% of classes have <10% of future STEM majors in class).

224.05 Bethany Cobb: Introductory Astronomy Student-Centered Active Learning at The George Washington University

All right, active learning strategies! SCALE-UP = Student-Centered Active Learning Environment for Undergraduate Programs.
GWU has own workbook for intro astro. Workbooks include definitions, numerical calculations (not sure how I feel about this), applications of knowledge. Work done in groups of 3 (which was discouraged in the workshop I just attended... but hey, if it works for them, why not?).
Lots of positive feedback, definite improvements in exam performance.
Lessons learned:
- spell out expectations on day 1.
- tell students the purpose of active learning strategies
- grading must me group-dependent
- no electronics (even laptops)

Introduced in Intro Astro class in Fall 2011, Fall 2013 incorporated in Intro to the Cosmos.

224.06 Kate Meredith: SkyServer Voyages: Next-Generation Educational Activities using the Sloan Digital Sky Survey

Former middle/high school teacher. Cool! Speaker also looks familiar...
Sloan SkyServer project (old site): http://skyserver.sdss.org/dr1/en/proj/
Research has been done into how to make effective inquiry-based science instruction. SkyServer has, as such, undergone recent rewrites.
I wanna check this stuff out IF I ever have the free time to do so.
Will be pilot testing this summer before (hopeful) launch!

(Man, trying to live-blog these sessions while having Twitter conversations on EPO in astronomy is tough, I keep finding myself ending up behind by a bit. Good convo though.)

224.07 Kathryn Williamson: The Space Public Outreach Team (SPOT)
(All right! More acronyms!)

Leaders write slideshow presentations, educators request presenters to appear in class.
Presenters recruited from all majors. Receive stipend, learn public speaking and other skills.
Reach 10,000 students per year (which is 10% of Montana's secondary school students!)
Now being piloted in West Virginia (presenter moved to NRAO).

224.08 Michael Martynowycz Inspiring a future generation of Astronomer and Astrophysicists during the 48th and 49th annual Astro-Science Workshop

Why do the Astro-Science Workshop? General decline in STEM interest, increase in global competition, growth of STEM fields, minimal experimental exposure in schools, lack of access to advanced STEM classes. Operates out of Alden planetarium. http://www.adlerplanetarium.org/astro-science-workshop/
Program consists of...
Advanced classroom discussions: physics, astronomy, student's choice
Student Driven projects: only requirement is to have something done by the end of the program
Guest speakers from top tier institutions give talks on current research topics

Successful projects include
- sampling Earth's magnetic field
- speed of sound wrt altitude
- balloon dynamics

224.09 Connie Walker: Dark Skies Africa: an NOAO and IAU OAD Program on Light Pollution 
(Go Connie!)
Goals: be responsible stewards in safeguarding dark skies and point out inefficiencies.
Active in 12 countries in sub-Saharan Africa.
Google+ Hangouts used to keep in touch with coordinators, teach trainers how to do activities. Trainers then go on to train actual teachers.
Challenges include Internet connections, attendance, getting resources through customs.
Will be reviewing progress reports, evaluations, look into improvements. Hope for more IAU funding.

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