Planet Survey Mission

1. Planet Survey Mission Tim Healy Tony Perry

2. Outline • Introduction • Finding Planets • Pulsar Timing • Astrometry • Polarimetry • Direct Imaging • Transit Method • Radial Velocity • Selecting Planets • Recap • What else do we want to know? • Proposed Plan

3. Introduction

4. (NASA)

5. Finding Planets

6. Pulsar Timing Method • First exoplanet confirmation! (1992) • Poor candidates for life Wolszczan and Frail, 1992

7. Astrometry • Precisely measure a star’s position over time • Mutual center of mass (barycenter) • Successful in characterizing binary star systems • Inaccurate claims of ‘unseen companions’ • Not useful unless planet is massive • Good as a complementary technique

8. Polarimetry • Un-polarized starlight • When the light reflects of a planet’s atmosphere, it becomes polarized by interacting with the molecules in the atmosphere • Analyze light in search of polarization • No planets found using this method University of Hertfordshire

9. Land-Based Direct Imaging • Technological Aspects • Larger Mirrors • Atmospheric Distortions • Adaptive Optics (e.g. Keck) • Glare from host star • Coronograph (e.g. Gemini Planetary Imager) • > 5 AU • Optical and Near IR spectra • Results • Potentially useful for finding life Simulation of Coronograph, (GPI) Keck II w/laser guide (CASA)

10. Direct Imaging – Hubble Telescope • Difficult to directly detect planets (extremely faint light sources) • Low Earth orbit in 1990 • View the near ultraviolet, visible, and near infrared • Outside the distortion of Earth’s atmosphere (no background light) • Ultra-Deep Field image • 2006 - Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS) • 16 extrasolar candidate planets discovered • When extrapolated, strong evidence of about six billion Jupiter-sized planets (NASA) http://www.youtube.com/watch?v=HAWMa_YEuKI

11. Transit Photometry Method • Dip in flux ~10^-5 • Space-based • Mass, period • T, habitability (NASA) http://www.youtube.com/watch?v=vjdxJQj4QHY

12. Transit Method (Kepler Mission) • Looking for terrestrial planets in habitable zones • Launched 3/7/2009 • Solar neighborhood-like region • Orbit: • Earth-trailing, (372.5 days) • Off-ecliptic • 6 year mission • 3 transits for significance • Follow-up Observing • Good start to look for life Kepler(NASA)

13. 2321 candidates around 1790 stars • 61 confirmed • (2/27/12) • 2321 candidates around 1790 stars • 61 confirmed • (2/27/12) Blue are habitable candidates 48 canidates 1 confirmed (Kepler 22b)

14. Radial Velocity (Doppler Spectroscopy) • Similar to Astrometry • Radial velocity calculated from displacement in parent star’s spectral lines due to the Doppler effect • Modern spectrometers can detect velocity variations 1 m/s or less • High Accuracy Radial Velocity Planet Searcher (HARPS) • Most productive planet hunting technique by far • When used in combination with the Transit Method, the planet’s true mass can be estimated

15. Radial Velocity - HARPS • Surveyed 102 red dwarfs • Thought to make up ~80% of the stars in our galaxy • 40% of all red dwarf stars have a super-Earth orbiting the habitable zone • Estimated tens of billions of these planets exist within the Milky Way • Stellar eruptions, flares msnbc - Artist rendition of sunset on super-Earth Gliese 667 Cc

16. Selecting Planets

17. Compiled Results • Catalog of planets (mass, period, host star) Lunineet al., 2009

18. Open Questions • Rocky or gas giant • Atmosphere • Orbit stability • Presence of: • Water • Methane • Carbon Dioxide • Plate Tectonics • Satellite(s)

19. Proposed Plan

20. Proposed Plan • Utilize two most productive planet searching techniques • Transit Method (Kepler) • Radial Velocity (Doppler) • Kepler - mission cost for entire life cycle is ~$600 million • Doppler - ESO 3.6 m telescope cost is $41.7 million (HAPRS was installed in 2002 on this telescope) • James Webb Space Telescope – 2018 launch date • ELT, first light 2020s • Astronomer median annual wage: $95,500 • Mission cost: $1 mil per year

21. Questions?