deerp: the next exoplanet finderlunar.earth.northwestern.edu/courses/351/planets.pdf · 2011. 5....
TRANSCRIPT
DEERP:The Next Exoplanet Finder
Ben HeathDavid CaratelliLeah Isaman
Sebastien Zany
Transit Method
● Looking at the dimming of a star's light as a planet passes in front
http://www.sciencenews.org/view/generic/id/62850/title/Still_no_Earths,_but_getting_closer
Transit Comparisons
http://www.dailymail.co.uk/sciencetech/article-1382658/55-Cancri-e-Remarkable-new-holds-key-planet-evolution.html
Kepler Mission ExamplesThe Good
Kepler Mission ExamplesThe Bad
Kepler Mission ExamplesThe Ugly
You Can Help!
If you want to help sift through Kepler Data, go to
www.planethunters.org
Radial Velocity
● Measuring the "wobble" of a star due to planet using doppler shift in spectrum
http://en.wikipedia.org/wiki/Radial_velocity_method
Blueshifts and Redshifts
http://snap.lbl.gov/science/darkenergy.php
Planet Mass SMA "Wobble"
Earth 1 AU 0.09 m/s
Earth 0.008 AU 1 m/s
Super-Earth (Earth x 5) 1 AU 0.48 m/s
Super-Earth 0.2 AU 1 m/s
Neptune (Earth x 17) 30 AU 0.28 m/s
Neptune 2.3 AU 1 m/s
Neptune 1 AU 1.5 m/s
Jupiter (Earth x 317) 5 AU 12.7 m/s
Jupiter 802.6 AU 1 m/s
Jupiter 1 AU 28 m/s
Wobbles Around a Solar Mass Star
Smallest detectable planet at 1 Au is about 11 Earth masses
Scale Comparisons
Combination of 2 images from Wikipedia
Other Methods
● Direct Imaging● Astrometry
http://www.dailymail.co.uk/sciencetech/article-1290919/First-photo-planet-circling-distant-sun-outside-solar-system.html
http://en.wikipedia.org/wiki/Radial_velocity_method
Gravitational Microlensing
-works at distances of thousands of light years
-Information on mass and distance to the star
-Identify free-floating planets?
-Best method to look for Earth sized planets in the habitable zone?
http://planetquest.jpl.nasa.gov/science/finding_planets.cfm http://bustard.phys.nd.edu/MPS/
http://lcogt.net/en/blog/egomez/sensitivities-exoplanet-search-methods
Pros: Best method for habitable planets Can "see" further than other methods Identify free floating planets Gravitational microlensing not only used for planet detection Cons: Depends on rare events effects of variable stars? hard to measure distances between Earth and star
Optical Gravitational Lensing Experiment
Looked for microlensing events in general
100 million stars observed
500 microlensing events small portion were planets
Other networks confirmed planet findings.
http://www.planetary.org/explore/topics/extrasolar_planets/extrasolar/microlensing.html
Space Based vs. Ground Based
-cost -resolution -predictions
http://www.universetoday.com/32556/5-spinoffs-from-the-hubble-space-telescope/
http://lcogt.net/en/blog/egomez/sensitivities-exoplanet-search-methods
http://planetquest.jpl.nasa.gov/NavigatorForum/documents/May18-2007/10-AnExtrasolarPlanetCensusMicrolensingPlanetFinder-Bennett.pdf
The Mission
● Joint exoplanet/dark energy probe● SpaceX private launch vehicle● Orbit considerations● Satellite design
Joint exoplanet/dark energy probe
Both need:● Infrared● Large detector● Wide field of view
DEERP:Dark Energy/ExoplanetResearchProbe
SpaceX private launch vehicle
● SpaceX current technology○ $10.9M for 1010kg payload to LEO○ $54M - $59.5M for 4540kg payload to GTO (Falcon 9)
■ or 10450kg to LEO (also Falcon 9)○ $80M - $125M for 53000kg to LEO (Falcon Heavy)○ Aiming for Mars in 10 years
● NASA○ Used Delta II to launch 1039kg Kepler at $36.7M to HCO
Orbit considerations
● Kepler mission is in Earth-lagging orbit around the sun => probably want that too
Satellite design - see MPF proposal