1. Life in the Universe I. astronomy Páll Jakobsson (Palli) (pja@hi.is) 10 January 2013 “If you wish to make an apple pie from scratch, you must first invent the Universe.” Carl Sagan (1934-1996)

2. 1. Inngangur 1.1 Aaaaa 1.2 Bbbbb Distance: 25 light years

3. Tracking Fomalhaut b from 2004-2012

4. 4 Distance: 130 light years

5. Distance: 25 light years Distance: 70 light years M = 9 ∙ M Jupiter

7. Known Exoplanets 1992: a few are discovered around a neutron star! 1995: the first around Sun-like star (indirect measurement). January 2013: 854 (http://exoplanet.eu): 1)Radial velocity + astrometry: 498 (386 planetary systems) 2)Transits: 291 (236 planetary systems) 3)Microlensing: 16 (15 planetary systems) 4)Imaging: 32 (28 planetary systems) 1), 2) and 3) are indirect measurements.

8. Venus Transit in June 2012

9. 9 Transit Graph

10. 10 Transit Graph Provides information on the radius of the exoplanet.

11. 11 Probability of a Transit Detection?

12. 12 Where is Kepler Looking?

13. The Kepler Planet Candidates (~2300) (NB: only 105 confirmed planets)

14. Kepler-20: An Unusual Planetary System (5 planets in small orbits)

15. Kepler-20: large, small, large, small, large Kepler-20b: 1.9 ∙ R Earth Kepler-20e: 0.9 ∙ R Earth Kepler-20c: 3.1 ∙ R Earth Kepler-20f: 1.0 ∙ R Earth Kepler-20d: 2.8 ∙ R Earth 760 °C 430 °C

16. 16

17. (the first rocky exoplanet to be discovered)

18. 18 6 planets!

19. 19 The Habitable Zone (shown in green)

20. Earth 2.0

21. Kepler-47 (a system with more than one planet orbiting a pair of stars)

26. 26 Astrometry (ísl: stjörnuvagg) A system of two (or more) bodies orbit around their mutual centre of mass. The change in the stellar position (wobble) gives the planet mass. Example: M Jupiter and d = 1 AU. Assume the system lies 3 light years from Earth. Stellar wobble: 1 milliarcsecond. Now put an “Earth” instead and move the system to 30 light years. Stellar wobble: 0.3 microarcsecond. No chance measuring that today. SIM PlanetQuest: 2016?

27. Motion of the Sun (distance: 30 ly)