Exoplanets - UW Blogs Networkblogs.uw.edu/suberlak/files/2013/09/Astr_101_Exoplanets1.pdf ·...
Transcript of Exoplanets - UW Blogs Networkblogs.uw.edu/suberlak/files/2013/09/Astr_101_Exoplanets1.pdf ·...
ExoplanetsAstr 101, Fall 2014
Exoplanets : outline
1) Why should we look for them2) Types of exoplanets discovered3) Detection methods4) Planetary atmospheres5) Habitable zones6) Future
Understanding formation of planets
- can we predict that SS should be the way it is from first principles and knowledge of all boundary conditions?
Why look for exoplanets?
To answer questions:- Are planets common or rare? - How do they form ? - How do they depend on location in the Galaxy, etc.
Exoplanets : outline
1) Why should we look for them2) Types of exoplanets discovered3) Detection methods4) Planetary atmospheres5) Habitable zones6) Future
Diversity of Exoplanets
SizeDistance from a star
Multi-planet systems
Number of planets (here Kepler 11-b)
Exoplanets : outline
1) Why should we look for them2) Types of exoplanets discovered3) Detection methods4) Planetary atmospheres5) Habitable zones6) Future
Direct imaging
Direct imaging
HR 8799
Gravitational Microlensing
- planet bends light from distant stars, and makes them appear brighter
Transits
Transits: limitations
- easier to detect bigger planets - why?- require particular alignment of the planetary orbital plane and our line of sight
Radial velocity
Detect the wobble of the star, as they both orbit the common center of mass
Radial velocity
Radial Velocity
* simulator: http://astro.unl.edu/naap/esp/animations/radialVelocitySimulator.html
Exoplanets : outline
1) Why should we look for them2) Types of exoplanets discovered3) Detection methods4) Planetary atmospheres5) Habitable zones6) Future
Transmission spectroscopy
Light contains many wavelengths , with useful information
Atmospheric properties
Questions to answer:
- what molecules are there ?- temperature profile ?- the structure of the atmosphere (clouds, hazes)
Problems with spectra
- Lots of noise - models are degenerate
GJ 1214b models: H dominated H with clouds Water dominated
Exoplanets : outline
1) Why should we look for them2) Types of exoplanets discovered3) Detection methods4) Planetary atmospheres5) Habitable zones6) Future
Habitable Zone
Could we live there?
Exoplanets : outline
1) Why should we look for them2) Types of exoplanets discovered3) Detection methods4) Planetary atmospheres5) Habitable zones6) Future
Future
Thirty Meter Telescope Giant Magellan Telescope
- more resolution- more planets- more science!
Questions?