1. Extrasolar planets Emre Işık (MPS, Lindau) S 3 lecture Origin of solar systems 14 February 2006

2. Outline Planet detection methods –Methodology –Some recent results Statistical properties of exoplanets Future prospects

3. Struve, O. 1952 Obs., 870, 199

5. Detection techniques I Precise stellar radial velocities to observer N. Strobel to observer N. Strobel

8. Detection techniques II Transit photometry  a = (P orb R  ) /  t  f / f  = (R p / R  ) 2

9. Detection techniques II Transit photometry Advantages Easy (if automated!), small telescopes with good sites/detectors Possibility to detect low-mass planets, especially from space (Kepler mission, 2008) Disadvantages Transit probability low; simultaneous observations of many stars Confusion with starspots, multiple stars Planets around binary stars Deeg (1998) Reflection effect

10. HST light curve of HD 209458 b Brown et al. (2001) Stellar radius and limb-darkening profile Planet's mass and radius No rings around the planet No moons with M > 3 M E (repeated obs.)

11. Detection techniques III Microlensing

12. Detection techniques III Microlensing events OGLE 2003-BLG-235/MOA 2003-BLG-53 Discovered planet: 1.5 M J @ 3 AU Bond et al. 2004, Astroph. J. Letters, 606, L155

13. Detection techniques III Microlensing events Discovery of a Cool Planet of 5.5 Earth Masses. OGLE-2005-BLG-390 Beaulieu et al., 2006, Nature, 439, 437Nature, 439, 437 Discovered planet: 5.5 M E @ 2.6 AU

14. Detection techniques IV Astrometry “Celestial” motion of the Sun due mainly to Jupiter & Saturn, as seen from 33 light years away…

15. Astrometry A Jupiter analog orbiting 5 AU from a solar-type star produces an astrometric amplitude of 0.5 milliarcsec (mas). A star with planet close to (about 1 arcmin) to a star without planet is needed. Direct, short CCD exposure at Palomar 5m and Keck telescopes may yield 0.1 mas. Palomar test-bed interferometer yields 60-70 μas, VLTI should allow 20 μas. Space missions may do better as interference from terrestrial atmosphere is eliminated. As of 1998, no object has been found. Technique is in its infancy. Big telescope resources are needed.

16. Detection techniques V Direct imaging !

17. Visible lightInfrared light

18. Name: 2M1207 b Msini: 5 ± 1 M J Radius:1.5 R J Temperature1240 ± 60 K Semi-major axis: (projected dist.) ~ 55 AU Orbital period: > 2450 yr Mass (star/M_sun): 0.025 NACO/VLT image, Chauvin et al. 2005 Detection techniques V Direct imaging !

19. Substellar companion to GQ Lupi IR image (NACO/VLT) GQ Lupi (A) orbited by a planet (b) at a distance of ~20xJupiter-Sun. GQ Lupi: 400 ly, 0.7 M  Mass: 1-42 M J

20. Detection techniques VI [reflection/absorption] spectroscopy

26. Caution: “planet occurrence” is biased by RV sensitivity!

27. Properties of the detected planets Lineweaver & Grether 2003

28. Properties of the detected planets Lineweaver & Grether 2003

29. Extrapolations Lineweaver & Grether 2003

32. Evolutionary models Different assumptions on the inhibition of cooling by irradiation from the parent star, and the planet's internal structure (Burrows et al. [2000], Bodenheimer et al. [2001] and Guillot and Showman [2002]) Fig.: Collier Cameron (2002)

33. The future: Future of future: 2015 - 2025 CO 2 O3O3