My work in Astronomy

A6f78eb8c4b69c5f49ed82641138a316?s=47 Stefano Meschiari
December 31, 2015
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My work in Astronomy

A6f78eb8c4b69c5f49ed82641138a316?s=128

Stefano Meschiari

December 31, 2015
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  1. Hi, I’m STEFANO MESCHIARI and I study EXOPLANETS Civitas Learning

    — 11/11/2015 UT AUSTIN/MCDONALD OBSERVATORY
  2. My work: overview Systemic • A package to analyze exoplanetary

    data • A virtual lab for teachers & students SAVE/Point • A pilot platform for education • 4 games and apps ready to play • Discovering new exoplanets • Understand how they form • Creating apps for education & outreach 0.0 0.5 1.0 1.5 2.0 2.5 3.0 -5 0 5 10 Time [JD] RV, Planet b [m/s] Q01 KECK APF 0 1 2 3 4 5 6 7 -10 -5 0 5 Time [JD] RV, Planet c [m/s] Q01 KECK APF -10 -5 0 5 10 RV, Planet f [m/s] Q01 KECK APF 0 20 40 60 80 -10 -5 0 5 10 Time [JD] RV, Planet g [m/s] Q01 KECK APF 0 500 1000 1500 2000 -10 -5 0 5 10 Time [JD] RV, Planet h [m/s] Q01 KECK APF -5 0 5 Residuals [m/s]
  3. What are exoplanets? SINCE 1995, WE NOW KNOW APPROXIMATELY 5,000

    PLANET CANDIDATES! 51 Peg b Gliese 581d Kepler 16 ABb Earth twin Jupiter analog with exomoon
  4. What are exoplanets? SINCE 1995, WE NOW KNOW APPROXIMATELY 5,000

    PLANET CANDIDATES! 51 Peg b Gliese 581d Kepler 16 ABb Earth twin Jupiter analog with exomoon Exoplanetary systems don’t look like the Solar System. Why? PROBLEM:
  5. 10-1 100 101 102 103 100 101 102 103 104

    105 Period [days] Mass [MEarth ] Discovery method RV Transit Imaging Timing Microlensing Are we unique ❄ snowflakes❄? COPERNICAN MEDIOCRITY PRINCIPLE: PROBABLY NOT. MASSIVE SELECTION EFFECT Earth Jupiter Saturn Uranus Harder to detect
  6. Are we unique ❄ snowflakes❄? COPERNICAN MEDIOCRITY PRINCIPLE: PROBABLY NOT,

    BUT… 0.125 AU HD 219134 Mercury Earth Vogt, Burt, Meschiari et al., 2015
  7. Answering the why (1) FIND MORE EXOPLANETS! Automated Planet Finder

    (APF) Keck Discovering new exoplanets through data 0.0 0.5 1.0 1.5 2.0 2.5 3.0 -5 0 5 10 Time [JD] RV, Planet b [m/s] Q01 KECK APF 0 1 2 3 4 5 6 7 -10 -5 0 5 Time [JD] RV, Planet c [m/s] Q01 KECK APF 0 5 10 15 20 -10 -5 0 5 10 Time [JD] RV, Planet f [m/s] Q01 KECK APF 0 5 10 net d [m/s] Q01 KECK APF 0 20 40 60 80 -10 -5 0 5 10 Time [JD] RV, Planet g [m/s] Q01 KECK APF 0 500 1000 1500 2000 -10 -5 0 5 10 Time [JD] RV, Planet h [m/s] Q01 KECK APF 2451000 2453000 2455000 2457000 -5 0 5 Time [JD] Residuals [m/s] 0.0 0.5 1.0 1.5 2.0 2.5 3.0 -5 0 5 10 Time [JD] RV, Planet b [m/s] Q01 KECK APF 0 1 2 3 4 5 6 7 -10 -5 0 5 Time [JD] RV, Planet c [m/s] Q01 KECK APF 0 5 10 15 20 -10 -5 0 5 10 Time [JD] RV, Planet f [m/s] Q01 KECK APF 0 10 20 30 40 -10 -5 0 5 10 Time [JD] RV, Planet d [m/s] Q01 KECK APF 0 20 40 60 80 -10 -5 0 5 10 Time [JD] RV, Planet g [m/s] Q01 KECK APF 0 500 1000 1500 2000 -10 -5 0 5 10 Time [JD] RV, Planet h [m/s] Q01 KECK APF 2451000 2453000 2455000 2457000 -5 0 5 Time [JD] Residuals [m/s] Meschiari et al., 2009, 2010, 2011; Vogt, Burt, Meschiari+15; Rowan & Meschiari et al., Meschiari et al. 2015 submitted; + 10 more papers
  8. Answering the why (2) HOW ROBUST IS PLANET FORMATION? Understanding

    how planets form in extreme conditions Meschiari et al., 2008, 2012, 2012, 2014; Meschiari et al., 2015, in prep
  9. Answering the why (2) HOW ROBUST IS PLANET FORMATION? Understanding

    how planets form in extreme conditions Meschiari et al., 2008, 2012, 2012, 2014; Meschiari et al., 2015, in prep
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  13. Answering the why (3) EMPOWER OTHERS! " Designing apps &

    games for science and education Systemic Super Planet Crash Orbits GravityKit SAVE/Point kiosk Open sourced on GitHub http://github.com/stefano-meschiari
  14. My work in a nutshell THE SCIENCE SIDE... Getting astronomical

    data (telescope observations, new discoveries, …) Writing code (data analysis, physical simulations, …) 2451000 2452000 2453000 2454000 2455000 2456000 2457000 -30 -20 -10 0 10 20 d[, 1] d[, 2] Science
  15. My work in a nutshell ...AND THE ASTRONOMY EDUCATION SIDE

    Writing code (HTML5/JavaScript web development) Education Designing apps & games (Systemic, Super Planet Crash, SAVE/Point, …)
  16. Radial Velocity data DOPPLER EFFECT + LOTS O’ STELLAR NOISE

  17. Radial Velocity data DOPPLER EFFECT + LOTS O’ STELLAR NOISE

  18. Radial Velocity data DOPPLER EFFECT + LOTS O’ STELLAR NOISE

  19. Radial Velocity data DOPPLER EFFECT + LOTS O’ STELLAR NOISE

  20. Radial Velocity data DOPPLER EFFECT + LOTS O’ STELLAR NOISE

    Cochran’s law (1992) “Thou shalt not embarrass thyself and thy colleagues by claiming false planets.” “Controversial” detections (about 10%)
  21. Systemic: a package/IDE for exoplanets LIVE DEMO TIME! HOPEFULLY NOTHING

    CRASHES ✌ Systemic (the offline/science version)
  22. Systemic’s architecture & entry points MUST… NOT… FORGET… ANY OF

    THESE LANGUAGES… Java (UI) Pipe R (High-level scripting) Dyncall C (libsystemic) Multiple processes Multithreaded Linking GSL SWIFT (FORTRAN)
  23. Example: HD219134 DATA SPANNING 11 YEARS -10 0 10 20

    2004 2007 2010 2013 2016 Date Radial velocity [m/s] Dataset APF KECK Q01 Vogt, Burt, Meschiari+15
  24. Orbital plot INNER AND OUTER PLANETARY SYSTEM 1 AU 0.125

    AU Inner planetary system Whole system
  25. 10 Period of planet b Density 3.0926 3.0930 3.0934 0

    1000 3000 Mass of planet b Density 0.006 0.010 0.014 0 100 200 300 Mean anomaly of planet b Density 0 50 100 150 0.000 0.010 0.020 Semi-major axis of planet b Density 0.038470 0.038474 0.038478 0e+00 2e+05 4e+05 Semiamplitude of planet b Density 1.0 1.5 2.0 2.5 0.0 0.5 1.0 1.5 2.0 Period of planet c Density 6.761 6.763 6.765 6.767 0 200 400 600 Mass of planet c Density 0.005 0.010 0.015 0.020 0 50 150 250 Mean anomaly of planet c Density 0 50 100 150 200 0.000 0.005 0.010 0.015 Semi-major axis of planet c Density 0.06480 0.06482 0 40000 80000 Semiamplitude of planet c Density 0.5 1.0 1.5 2.0 0.0 0.5 1.0 1.5 2.0 Period of planet d Density 22.78 22.80 22.82 0 20 40 60 80 Mass of planet d Density 0.015 0.025 0.035 0 50 100 150 Mean anomaly of planet d Density 200 250 300 350 0.000 0.010 0.020 Semi-major axis of planet d Density 0.14565 0.14575 0.14585 0 5000 15000 Semiamplitude of planet d Density 1.5 2.0 2.5 3.0 0.0 0.5 1.0 1.5 Period of planet e Density 46.66 46.70 46.74 0 5 15 25 35 Mass of planet e Density 0.050 0.060 0.070 0.080 0 20 60 100 Mean anomaly of planet e Density 240 260 280 300 320 0.00 0.01 0.02 0.03 Semi-major axis of planet e Density 0.2349 0.2351 0 4000 8000 Semiamplitude of planet e Density 3.5 4.0 4.5 5.0 5.5 0.0 0.5 1.0 1.5 Period of planet f Density 93.6 94.0 94.4 94.8 0.0 1.0 2.0 Mass of planet f Density 0.02 0.03 0.04 0.05 0 20 40 60 80 Mean anomaly of planet f Density 0 50 100 150 200 0.000 0.004 0.008 Semi-major axis of planet f Density 0.3735 0.3745 0.3755 0.3765 0 200 600 1000 Semiamplitude of planet f Density 1.0 1.5 2.0 2.5 0.0 0.5 1.0 1.5 Period of planet g Density 2050 2150 2250 2350 0.000 0.004 0.008 Mass of planet g Density 0.25 0.30 0.35 0.40 0 5 10 15 20 Mean anomaly of planet g Density 0 50 150 250 350 0.000 0.003 0.006 Semi-major axis of planet g Density 2.95 3.05 3.15 3.25 0 2 4 6 8 10 Semiamplitude of planet g Density 4.5 5.0 5.5 6.0 6.5 7.0 7.5 0.0 0.4 0.8 1.2 Eccentricity of planet g Density 0.00 0.10 0.20 0.30 0 2 4 6 8 Long. of periastron of planet g Density 0 50 150 250 350 0.000 0.004 0.008 Noise, Q01 Density 0.5 1.0 1.5 2.0 0.0 0.5 1.0 1.5 2.0 Noise, KECK Density 2.0 2.5 3.0 3.5 0.0 0.5 1.0 1.5 2.0 Noise, APF Density 1.5 2.0 2.5 0.0 0.5 1.0 1.5 2.0 MCMC NATIVE CODE + MULTITHREADED IMPLEMENTATIONS Markov-Chain Monte Carlo
  26. Residuals BEAUTIFULLY NORMAL & CORRELATED WITH STELLAR ACTIVITY -10 -5

    0 5 0.20 0.25 0.30 0.35 0.40 Activity Velocity residuals [m s-1] 2000 2005 2010 2015 Year Dataset KECK APF Activity Velocity residuals [m/s] Q-Q plot of residuals Residuals vs. activity
  27. Systemic R package NATIVE CODE + MULTITHREADED IMPLEMENTATIONS - Bootstrap


    - Cross-validation
 - Local optimization 
 Simplex, gradient descent, Levenberg-Marquardt
 - Global optimization 
 differential evolution, simulated annealing, MCMC
 - Long-term integration over millions of years http://github.com/stefano-meschiari/Systemic2
  28. Widely used in the community …INCLUDING AS A CITIZEN SCIENCE

    TOOL More than 5,000 registrations, used to discover/ characterize more than 40 planetary systems. Makes for a great citizen science/authentic science experience tool. Fully half of registrations from teachers, students, and non-academic users. Peter Jalowiczor Dominick Rowan
  29. Widely used in the community …INCLUDING IN THE CLASSROOM Top

    complaints: It’s too hard to install! It’s too hard to use!
  30. Systemic’s architecture for the Web MY MAKEFILE HAS A JAVASCRIPT

    TARGET Java (UI) Pipe R (High-level scripting) Dyncall C (libsystemic) Multiple processes Linking GSL SWIFT (FORTRAN) Emscripten “make -f Makefile.js” JavaScript (libsystemic.js) HTML5 (UI) <script>
  31. Systemic Live RUNS ON YOUR FAVORITE BROWSER (DESKTOP/MOBILE)

  32. “The online Systemic Console is a real gift to the

    community. […] I use this site to train both undergraduate and graduate students – they love the power of this program.” 
 — Debra Fischer, Yale University “Systemic is simple enough to use that it can provide a hand-on ‘virtual lab’ for a large general education class, […] students can get a taste of the scientific process even before they learn to program” – 
 — Eric Ford, Penn State “[...] After demonstrating the relevant equations in class, students have a good feel for the physics involved, but not until they start to try to fit real data and extract real planets do they realize the how subtle, complex, and fun the real process is. ”
 — Mike Brown, Caltech, Pluto-killer “I have used Systemic for several years in my class for advanced undergraduate physics majors. […] Systemic is extremely sophisticated, but easy to use, so it allows students to get a feeling for the tools used in real exoplanet research.”
 — Jonathan Fortney, UC Santa Cruz Testimonials RUNS ON YOUR FAVORITE BROWSER (DESKTOP/MOBILE)
  33. Systemic Live RUNS ON YOUR FAVORITE BROWSER (DESKTOP/MOBILE) Systemic is

    employed in classes at UT, Caltech, University of Florida, MIT, SJSU, Delaware, Yale, Columbia, UC Santa Cruz, and others, reaching ∼500 students to date, and is a homework set on the recurring MOOC “The Science of the Solar System” , taken by ∼13,000 Coursera students. Started to put a bit more serious thought about online astronomy education after that…
  34. Super Planet Crash A “MINIMUM VIABLE GAME” ABOUT GRAVITY

  35. Super Planet Crash A “MINIMUM VIABLE GAME” ABOUT GRAVITY

  36. ~15,000,000 games played by ~700,000 users since April Huffington Post

    The Verge Physics World SciAm News io9 Space.com VICE The Creators Project & others
  37. Success! BUT… I BROKE MY WEBSITE $ Imgur, io9 The

    Verge, HuffPost, VICE, Hacker News, Twitter Google Analytics, April-May 2014 CloudFront + some serious on-the-fly re-engineering of the game helped.
  38. What do 15,000,000 clicks look like? TAKE A GUESS. Orbital

    spin Habitable zone (get bonus) I recorded on the server the coordinates of every click on the game area (the circle). Where are most of the clicks?
  39. U/L bias Closer to the controls on the left- hand

    side of the window; People pay more attention to upper field of vision “Crosshair” bias Empirical preference for cardinal directions (related to “oblique effect”?) Orbital spin What do 15,000,000 clicks look like? [SHOWING A SUBSET OF 100,000]
  40. SAVE /Point http://save-point.io

  41. Stefano (PI) Design & development Randi Educational content Joel Music

    & story Greg Accessibility for VI people Pilot project received “seed” funding by UT for 2014-2015.
  42. Philosophy of the pilot project OR Touch Gesture Reference Guide

    Press Double tap Tap Press and drag Drag Press and tap, then drag 1 2 Press and tap Multi-finger tap 1 2
  43. Philosophy of the pilot project • A suite of apps

    & games will provide students at all levels with a “virtual astronomy lab” in browser
 No installation hassle, can run on mobile platforms, easily accessible anywhere. OR Touch Gesture Reference Guide Press Double tap Tap Press and drag Drag Press and tap, then drag 1 2 Press and tap Multi-finger tap 1 2
  44. Philosophy of the pilot project • A suite of apps

    & games will provide students at all levels with a “virtual astronomy lab” in browser
 No installation hassle, can run on mobile platforms, easily accessible anywhere. • Prioritize accurate physics, real astronomical datasets, game-level fun and engaging design. OR Touch Gesture Reference Guide Press Double tap Tap Press and drag Drag Press and tap, then drag 1 2 Press and tap Multi-finger tap 1 2
  45. Philosophy of the pilot project • A suite of apps

    & games will provide students at all levels with a “virtual astronomy lab” in browser
 No installation hassle, can run on mobile platforms, easily accessible anywhere. • Prioritize accurate physics, real astronomical datasets, game-level fun and engaging design. • Easy scoring/grading systems for instructors. OR Touch Gesture Reference Guide Press Double tap Tap Press and drag Drag Press and tap, then drag 1 2 Press and tap Multi-finger tap 1 2 
 Classroom scores
  46. Philosophy of the pilot project • A suite of apps

    & games will provide students at all levels with a “virtual astronomy lab” in browser
 No installation hassle, can run on mobile platforms, easily accessible anywhere. • Prioritize accurate physics, real astronomical datasets, game-level fun and engaging design. • Easy scoring/grading systems for instructors. • Open source and easily customizable by schools and instructors. OR Touch Gesture Reference Guide Press Double tap Tap Press and drag Drag Press and tap, then drag 1 2 Press and tap Multi-finger tap 1 2 
 Classroom scores
  47. Orbits • An HTML5/JavaScript game (using Canvas)
 Backbone + Paper.js


    • All the level logic (story, interactions, properties) in an easy- to-edit YAML file
 Working on a customization interface for instructors
  48. None
  49. Interactive small-scale exhibi A cut-down version of our applications could

    be ideal for small astronomy demos and exhibits. Our group just got a small department grant to outfit several floors of our buildings with wall-mounted iPads running educational apps. A lot of kids don’t know how to use a trackpad or a mouse! Small-scale exhibits, interactive kiosks, activities for Visually Impaired users Touch-based (+sound/haptic feedback)
  50. At SXSW Gaming Expo Seattle Museum of Flight Interactive kiosks

    at UT In classrooms
  51. 0.125 AU My work: overview Systemic • A tool to

    analyze exoplanetary data • A virtual lab for teachers & students SAVE/Point • A pilot platform for education • 4 games and apps ready to play • Discovering new exoplanets • Understand how they form • Creating apps for education & outreach 0.0 0.5 1.0 1.5 2.0 2.5 3.0 -5 0 5 10 Time [JD] RV, Planet b [m/s] Q01 KECK APF 0 1 2 3 4 5 6 7 -10 -5 0 5 Time [JD] RV, Planet c [m/s] Q01 KECK APF -10 -5 0 5 10 RV, Planet f [m/s] Q01 KECK APF 0 20 40 60 80 -10 -5 0 5 10 Time [JD] RV, Planet g [m/s] Q01 KECK APF 0 500 1000 1500 2000 -10 -5 0 5 10 Time [JD] RV, Planet h [m/s] Q01 KECK APF -5 0 5 Residuals [m/s] Thank you!
  52. None
  53. Systemic R package 1 10 100 1000 10000 0 10

    20 30 [1] Residuals for 0-planet fit Period [d] Normalized power NATIVE CODE + MULTITHREADED IMPLEMENTATIONS Lomb-Scargle periodograms
  54. Case study: HD219134 SUBSTANTIAL VARIABILITY • 10−3 10−2 10−1 100

    101 0.1 1.0 S−index median S−index dispersion Observations • • • • • • 0 50 100 150 200 250 • • HD 219134 KECK stars Median activity Activity variability
  55. Check for stellar activity IS THE RV SIGNAL CORRELATED WITH

    THE ACTIVITY? -10 0 10 0.20 0.25 0.30 0.35 0.40 Activity Velocity [m s-1] 2000 2005 2010 2015 Year Dataset KECK APF
  56. Check for stellar activity IS THE RV SIGNAL CORRELATED WITH

    THE ACTIVITY? [1997,2008] (2008,2012] (2012,2015] -10 0 10 0.20 0.25 0.30 0.35 0.40 0.20 0.25 0.30 0.35 0.40 0.20 0.25 0.30 0.35 0.40 Activity Velocity [m s-1]
  57. Planetary parameters EXTRACTED FROM THE MARKOV-CHAIN MONTE CARLO OUTPUT

  58. Check for stellar activity IS THE RV SIGNAL CORRELATED WITH

    THE ACTIVITY? -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4 -400 -200 0 200 400 Lag Correlation
  59. Model comparison

  60. Systemic R package - HD32963 NATIVE CODE + MULTITHREADED IMPLEMENTATIONS

    P M MA e ω a K Noise Trend P Density M Density MA Density e Density ω Density a Density K Density Noise Density Trend Density Markov-Chain Monte Carlo modeling 1 AU
  61. Kepler’s 2014 bonanza More than 700 new planets confirmed! Image

    Credit: NASA Ames/SETI/J Rowe
  62. Kepler’s 2014 bonanza More than 700 new planets confirmed! Image

    Credit: NASA Ames/SETI/J Rowe