Yale astronomers take over operation of MOST satellite to gain precision in exoplanet discovery

Thu, 10/09/2014
Yale exoplanet hunters will take over operation of the Canadian Microvariability Oscillation of STars (MOST) space satellite for the next two months from October 10th to December 10th to observe two bright stars: tau Ceti and epsilon Eridani.  The Yale astronomers will also be using the ground-based CHIRON spectrometer that they built for the SMARTS 1.5m telescope in Chile to observe these same stars. The synergy of high precision space-based photometry from space and high precision velocity measurements from the ground is a first for astronomers. The goal is to understand photospheric signals that are obscuring the precision of velocity measurements. 
Prof. Debra Fischer, who leads the exoplanet team, explained: “We have detected hundreds of exoplanets by measuring the velocities of stars as they are tugged around a common center of mass by orbiting planets. However, we do not have the ability to detect Earth analogs. One of the big problems is that astronomers have not been able to distinguish flows from the atmosphere of the stars from the velocity of the star.  These observations will allow us to train our search algorithms to Earth-detecting precision.”
The Canadian MOST satellite is modest by any accounts.  UBC Professor Jaymie Matthews, who designed the satellite, nicknamed it the “Humble Space Telescope.” When Yale graduate student Matt Giguere learned that the Canadians had scheduled the decommissioning of the MOST satellite for September 2014, he realized that the space craft could provide the data that the Yale exoplanet team needed. “We wanted to figure out what part of the measured velocity wiggles were coming from the stellar atmospheres and there is no other space satellite that can do this.”  The Yale team has enough funding to operate the satellite for two months. Fischer said, “The Canadians complete shutdown of MOST on October 9th and we will wake it up and begin observing on October 10th.”