Life in the UniverseI. astronomy

Páll Jakobsson(pja@hi.is)

8 January 2013

“Somewhere, something incredible is waiting to be known.”Carl Sagan (1934-1996)

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