deerp: the next exoplanet finderlunar.earth.northwestern.edu/courses/351/planets.pdf · 2011. 5....

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