Michael Endl Board of Visitors Meeting - July 2009 The McDonald Observatory Planet Search Program Michael Endl Board of Visitors Meeting - July 2009
Science Questions: How frequent are “extrasolar” planets? What are their characteristics (e.g. mass, orbit)? How do planetary systems form? Is our Solar System typical? How common are Earth-like planets? How can we detect planets around other stars?
Stars are a billion times brighter… SCRIPT: Stars are a billion times brighter… ----------------------- WHAT’S ON THE SLIDE: Artist’s rendering of a lighthouse with beacon shining.
…than the planet …hidden in the glare. SCRIPT: …than the planet [Click space bar] …hidden in the glare. ----------------------- WHAT’S ON THE SLIDE: Artist’s rendering of a lighthouse with beacon off. A small firefly is perched atop the lighthouse lamp.
The “Radial Velocity” Technique:
The Search for Extrasolar Planets at McDonald Observatory Bill Cochran & Artie Hatzes Diane Paulson, Robert Wittenmyer, Stuart Barnes, Phillip MacQueen Michael Endl Hobby-Eberly 9 m Telescope 2001 - present Harlan J. Smith 2.7 m Telescope 1988 - present
1997: The first 2.7 m Survey Planet: P = 2.2 yrs a = 1.67 AU M ~ 1.7 M Jupiter
measurement precision HET/HRS measurement precision RMS = 3.11 m s-1 May 2008 Oct 2008 Jun 2009
HD 37605 b: the first HET planet m sin i = 2.85 +/- 0.3 MJup P = 54.2 +/- 0.23 d e = 0.74 +/- 0.01 K = 262.9 +/- 5.5 m s-1 a = 0.26 +/- 0.01 AU
Rho 1 Cnc e : the first extrasolar Neptune! HET Rho 1 Cancri: 2004: planet e minimum mass ~ 14 M Earth 2008: (+ planet f) planet e minimum mass ~ 10 M Earth
HD 155358: a double planet system around a metal poor star Planet b: m sin i = 0.89 ± 0.12 MJup Planet c: m sin i = 0.50 ± 0.08 MJup HET
Searching for other Earths
The “Transit” Method Searching for other Earths Earth: ~ 0.0085 % Viewing angle ~ orbital plane! Delta L / L ~ ( Rplanet / Rstar )2 Jupiter: ~ 1-2 % Earth: ~ 0.0085 % The “Transit” Method
March 2009: NASA’s KEPLER mission is launched!
Follow-up Observing Program (FOP): dRV [ cm / s ]