Extrasolar Planets - Michigan Technological University by wulinqing


									  Search for Life:
 Extrasolar Planets
        Robert Nemiroff
Michigan Technological University
 Physics X: About This Course

• Officially "Extraordinary Concepts in Physics"
• Being taught for credit at Michigan Tech
   o Light on math, heavy on concepts
   o Anyone anywhere is welcome
• No textbook required
   o Wikipedia, web links, and lectures only
   o Find all the lectures with Google at:
       "Starship Asterisk" then "Physics X"
   o http://bb.nightskylive.net/
   o asterisk/viewforum.php?f=39
Search for Extrasolar Planets

If life exists outside of Earth, it is likely on a planet.

• How common are planets around stars?
• How common are rocky planets?
• How common are planets in the habitable zone?
   o where liquid water can exist
• How common is water?
• How common are biomarkers?
Search for Extrasolar Planets

Hot topic in modern astronomy. Main techniques:
 • slight changes in pulsar timings
    o civilizations unlikely there (?)
         but read Dragon's Egg by R. Forward
 • slight doppler wobble of star due to planets
    o most planets now found this way
 • slight occultation of planet by star
    o Kepler satellite will likely find thousands
 • gravitational lensing
    o once and done, but can see low mass planets
 • direct image of planet
    o hard since parent star so bright
    55 Cancri: Familiar Planet Discovered
Illustration Credit & Copyright: Lynette Cook
             APOD: 2002 June 14
Water Claimed in Evaporating Planet HD 209458b
Illustration Credit: ESA, A. Vidal-Madjar (IAP, CNRS), NASA
APOD: 2007 April 17
A Dangerous Sunrise on Gliese 876d
Illustration Credit & Copyright: Inga Nielsen
(Hamburg Obs., Gate to Nowhere)
APOD: 2008 May 21
HR 8799: Discovery of a Multi-planet Star System
Credit: C. Marois et al., NRC Canada
APOD: 2008 November 17
Kepler's Streak
Credit & Copyright: Ben Cooper
APOD: 2009 March 9
CoRoT Satellite Discovers Rocky Planet
Illustration Credit: ESO/L. Calcada
APOD: 2009 September 23
                             A Giant Planet for Beta Pic
Credit: A.-M. Lagrange, D. Ehrenreich (LAOG), et al., ESO
                                      APOD: 2010 July 3
Companion of a Young, Sun-like Star Confirmed
Credit: Gemini Observatory, D. Lafreniere, R.
Jayawardhana, M. van Kerkwijk (Univ. Toronto)
APOD: 2010 July 4
Zarmina's World
Illustration Credit & Copyright: Lynette Cook
APOD: 2010 October 1
Kepler's First Five Exoplanets
Planets around Alpha Centauri?

RJN comment:

The Alpha Centauri system is the closest star system to the Sun, and
contains a star very much like our Sun. Does this star have
planets? We currently don't know. We should try harder to find out! At
4.3 light years distant, it might be a good far future outpost for humans.

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