Life in the Universe I. astronomy Pll Jakobsson 8 January 2013 Somewhere, something incredible is waiting to be known. Carl Sagan ( ) The Exoplanet Next Door Tau Ceti: A quintet of Exoplanets 2-6 times Earth masses 14 eXtreme Deep Field (XDF) An exposure time of 2 million seconds! 5,500 galaxies A small fraction of the angular diameter of the full Moon Hubble XDF (zoom-in) Hubble XDF (zoom-out) Looking Back into Time with the XDF 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. White dwarves and neutron stars