Cos 17 - underneath its surface with a period of about 12...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Class 17 Tuesday, March 11, 2008 11:10 AM First step in finding out whether life can possibly be abundant in the universe: find planets-- >exoplanets Exoplanets now found almost routinely, but rarely by direct observation Rather their presence is inferred by noting their gravitational effect on their parent star, causing it to have a small wobble that we can detect using the Doppler effect Of the 230 extrasolar planets now known, most have Jupietr mass or larger Detecting exoplanets using the Doppler shift And indirect technique, one observes the star, not the planet The star reacts to the gravity of the planet by moving in a small orbit around the center or mass of the star-planet system. Doppler shift due to stellar wobble Even the Sun, the reaction to Jupiter's gravitational pull orbits around a point that is just
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: underneath its surface with a period of about 12 years (the same as Jupiter's period around the sun). Gilese 876 double planet system One of the first planets to be detected by the wobble doppler effect Closer the planet is to the sun, the bigger the wobble Of the known planets, large amount of them are very large Some orbits are well determined In the infrared, planets are brighter than their stars Terrestrial planet finder launched in about 15 years Finding oxygen in their atmosphere would signal us to the possibility of life (photosynthesis But it's easier to find ozone than oxygen Can oxygen arise natyrally on n a=oxygen The Arecibo Radiotelecope, send signals out, 50k yrs we'll hear ther respnse and for pics...
View Full Document

This note was uploaded on 06/04/2008 for the course GE CLUST 70B taught by Professor Morris during the Spring '07 term at UCLA.

Page1 / 2

Cos 17 - underneath its surface with a period of about 12...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online