1. All About Exoplanets Dimitar D. Sasselov Harvard-Smithsonian Center for Astrophysics

2. Planets Orbiting Other Stars Number of planets discovered around stars like our Sun: 123 planets 13 multiple planet systems

3. A new field with 3 basic questions: How do planets & planetary systems form and survive ? What is the physical diversity of planets ? What is the planetary perspective to the origin of life ?

4. Environments we can call home

5. A new field with 3 basic questions: How do planets & planetary systems form and survive ? What is the physical diversity of planets ? What is the planetary perspective to the origin of life ?

6. UpsAnd System vs. Solar System

7. Planets Form Shortly After Their Parent Stars: Galaxy Molecular Cloud Complex Star-Forming “Globule” Circumstellar Disk Extrasolar System ?

8. Methods for Planet Discovery: several, but only 3 have been successful so far Radial Velocity Measurements (119) - looking for the Doppler shifts due to “Stellar Wobble” as planet pulls on star, Transit Measurements (3) - looking for periodic dimming as planet eclipses star. & Gravitational Microlensing signal (1).

10. New Method of Discovery Transit Measurements

11. Venus in Front of the Sun

12. Transit Measurements

13. Evidence for Planet OGLE-TR-56b Transit Light Curve Radial Velocities Torres, Konacki, Sasselov, Jha, 2004, Astrophys. J.

14. What did we find ? Unique Orbit = 29 hours Mass = 1.4 Jupiters Density = 1.0 g/cm3 denser than Saturn Iron rain

15. OGLE-TR-113b Transit Light Curve Radial Velocities Konacki, Torres, Sasselov, Jha (2004)

16. The Other Known Transiting Extrasolar Planet HD 209458b: Dimming of light due to transit, observed with HST. Brown, Charbonneau, Gilliland, Noyes, Burrows (2001) Transits tell us DIRECTLY: Planet radius, INDIRECTLY: Planet density Planet composition

17. Model: Seager & Sasselov 2000 Detection: Charbonneau et al 2002

18. The HAT Network: FLWO Mt.Hopkins AZ

19. The HAT Network: Mauna Kea Obs. Hawaii

21. Mochejska et al. 2002 -2004

22. Survey for Transiting Exo-Planets in Stellar Systems Gaudi et al. 2002-2004

23. Surveying Extrasolar Planets: the First Step MOST - “Microvariability & Oscillations of Stars” - Canada’s First Space Telescope; We will use MOST to detect the reflected light from known “hot Jupiters”; The details of the reflected light will tell us about the particle size & composition of the planet’s clouds.

25. Photometric Light Curves Very slight changes in the light as planet changes phase, Requires precise photometry from space - MOST.

26. Scattered Light Curves: 3 Examples Seager, Whitney, & Sasselov 2000 Green, Matthews, et al. 2003 51 Peg @ 550 nm

27. Environments we can call home

28. One of Humankind’s Biggest Questions: What is the path from Stars to Life ? - a major inter-disciplinary effort, with - astrophysics providing the ‘stage’; - First step: to discover Earth twins.

29. What Would It Take ? Lynnette Cook

30. KEPLER: Search for Earth Twins NASA Mission - launch in 2007 Transit Search: ~100,000 stars Can detect planets like our Earth GOAL: discover 1,000’s of medium and giant planets; also ~12 Earths in habitable zones.

31. Terrestrial Planet Finder Find and characterize Earth-like planets Reduce the glare of the parent star by one million to one billion Launch date 2015 Observe stars within 50 light years Alcatel Space Industries