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Ge/Ay133

What (exo)-planetary science can be done with transits and microlensing?. Ge/Ay133. A Jupiter transit across the Sun is ~1%:. Curvature?. Limb Darkening and Transit Profiles:. Star. Probes composition of atmosphere at day-night terminator Can search for clouds, hazes, condensates. Planet.

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Ge/Ay133

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  1. What (exo)-planetary science can be done with transits and microlensing? Ge/Ay133

  2. A Jupiter transit across the Sun is ~1%: Curvature?

  3. Limb Darkening and Transit Profiles: Star • Probes composition of atmosphere at day-night terminator • Can search for clouds, hazes, condensates Planet Atmosphere HST STIS transits of HD 209458b from 290-1030 nm (Knutson et al. 2007a)

  4. Sometimes the absence of signal is interesting: Gilliland, R.L. et al. 2000, ApJ, 545, L47 No transits in 47 Tuc, `expectation’=30-40 (34,000 stars)

  5. Transits, approach #1: Sato, B. et al. 2005, ApJ, astro-ph/0507009 Search for transits in systems known to have planets at the doppler crossings.

  6. Transits and the Rossiter-McLaughlin effect (1924): Winn, J.N. et al. 2005, ApJ, 631, 1215

  7. Photometry can be straightforward: Amateur observations of HD 209458 b Bruce L. Gary, Santa Barbara, CA Arto Oksanen SBIG cameras, Meade telescopes, V filters

  8. Transits, approach #2: TrES-1 Search for transits in many stars using a suite of low cost robotic telescopes. Alonso, R. et al. 2004, ApJ, 613, L153

  9. Photometry from space can be extremely good: Brown, T.M. et al. 2001, ApJ, 552, 699 HD 209458 - HST The KEPLER mission is dedicated to photometry and can search for earth mass planets in the so- called habitable zone. www.kepler.arc.nasa.gov 95 Mpixel camera, 115 deg2 FOV, 4’’ pixels

  10. But ground-based work is making strides! Brown, T.M. et al. 2001, ApJ, 552, 699 HD 209458 - HST At this level of performance (0.47 milli-mag) the transits of hot Neptunes are detectable & transit timing can put stringent limits on perturbing planets into the Earth mass range.

  11. Rowe, J.F.. et al. 2006, ApJ, 646, 1241 Secondary eclipses can also put limits on the visible albedo. The MOST satellite finds A(HD209458b)<0.25 (1s) (Jupiter=0.5, 300-700 nm). Why so dark?

  12. Transit photometry from space: Kepler

  13. A comparison of transiting planet systems: As we’ll see, size is not a strong function of mass, so very accurate measurements are needed!

  14. Secondary ecplises in the IR with Spitzer, see photons from the hot Jupiters! T = 1060 ± 50 K A = 0.31 ± 0.14 Charbonneau, D. et al. 2005, ApJ, 626, 523

  15. Rapid Pace of Spitzer Transit Results: HD 189733b Mapping the temperature variation of a hot Jupiter… • T(max)~1200 K, T(min)~970 K • Hot spot ~30 ± 10° from the sub-stellar point • Bond albedo~0.30 • Must be reasonably efficient circulation from day to night side. T = 1060 ± 50 K A = 0.31 ± 0.14 Charbonneau, D. et al. 2005, ApJ, 626, 523

  16. Other routes to Earth-like planets?

  17. Microlensing example:

  18. Microlensing example:

  19. Are there Earth-like planets beyond the snow-line?

  20. Rapid Progress: Transiting Planets, 1 May 2007

  21. Ice/Rock Planets One year later (2008): 43 Systems And Counting

  22. HD 149026

  23. Other Correlations: Why would the mass/gravity of a close-in planet be tied to the period? May be some tie to the mass of the star… B. Hansen & T. Barman 2007, ApJ, 671, 61

  24. Other Correlations II: For a given Teq (not strictly distance since the spectral type varies…), two classes of planets versus Safronov number? B. Hansen & T. Barman 2007, ApJ, 671, 61

  25. Seems also to be tied to the mass of the planets: • Selection bias or poor stellar radii? X • Redistribution of energy? More next time… • Evaporation? X • (if “hot start”) • Tidal heating? • Planetesimals & migration (tie to Safronov #)? • Need composition(s)! B. Hansen & T. Barman 2007, ApJ, 671, 61

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