Debra Fischer

Debra Fischer's picture
Professor of Astronomy and of Geology and Geophysics

Debra Fischer is a Professor of Astronomy at Yale University who began hunting for exoplanets in 1997 by measuring Doppler shifts in the spectra of stars.  She has discovered hundreds of extrasolar planets with this technique, including the first known multiple planet system in 1999.  Dr. Fischer’s analysis of stellar spectra demonstrated that gas giant planets were more likely to form around stars with a higher abundance of heavy elements and she quantified the now well-known “planet-metallicity” correlation; with postdoctoral fellow Ji Wang, she has shown that this correlation does not hold for rocky planets, which form under a   wider range of environments. She led an international consortium from 2003 – 2008 to carry out a search for hot Jupiters orbiting metal-rich stars; that project detected more than 30 new extrasolar planets.  Some of  these planets transit in front of their host stars, enabling a measurement of the radius and mean density of the planets and permitting an observation of the atmosphere with transmission spectroscopy.

In her lab at Yale, Fischer’s team is developing next generation instrument designs to break current measurement precision records and detect Earth analogues that will be targets in the search for life on other worlds. She is the PI for CHIRON, a high-resolution, fiber-fed spectrometer commissioned at CTIO in June 2012; this instrument achieves a nightly precision of 0.5 m s-1 on bright inactive stars. She is PI for EXPRES, an ultra-stable instrument that aims for 10 cm/s radial velocity measurement precision that is being designed for the Discovery Channel Telescope at Lowell Observatory. The goal of EXPRES is an instrument that can distinguish velocity flows on the surface of stars from orbital velocities and this instrument will be used for the 100 Earths Project that Fischer is leading.  Fischer is also the co-chair for the NASA study of LUVOIR, a 12 to 16-m space telescope that is being evaluated as a flagship mission in 2035.