Bijan Nemati is a Principal Research Scientist at the University of Alabama in Huntsville. He received his Ph.D. in high energy physics from the University of Washington, based on his research on heavy quark decays detected at the Stanford Linear Accelerator Center. After post-doctoral work at the Cornell synchrotron, he left particle physics to work on advanced astronomical instruments at the Jet Propulsion Laboratory.
Inspired by work by other Discovery Institute fellows, particularly the Privileged Planet by Drs. Guillermo Gonzalez and Jay Richards, Dr. Nemati led several key testbeds at JPL that together demonstrated the feasibility of astrometric detection of Earth like exoplanets in the habitable zones of nearby sun-like stars. While it is now clear that genuine Earth-like planets around nearby sunlike stars are quite rare, the debate about their existence and abundance must be informed by searches with instruments that have the sensitivity to detect them.
Dr. Nemati’s work on the NASA flagship Space Interferometry Mission (SIM) proved that the instrument could self-calibrate at the levels needed to detect exo-Earths. For SIM this meant the self-calibration of its key optical distances with an error of less than the radius of a hydrogen atom and astrometric angle measurements to less than a billionth of a degree. For these achievements Dr. Nemati was awarded NASA’s Exceptional Engineering Achievement Medal.
Since 2014 Dr. Nemati has been part of the development team of an exoplanet imaging instrument that will be part of NASA’s Roman Space Telescope, scheduled for launch sometime after 2025. Almost all current methods that seek to detect exoplanets do so indirectly, by observing changes in the star’s position (astrometry method), intensity (transit method) or spectrum (radial velocity method). The simplest conceivable detection method has been elusive because of the overwhelming light for the planet’s host star. Dubbed CGI (for the Coronagraph Instrument), Roman telescope’s direct imager is designed to scatter away the host star’s light in order to enable the detection of photons from the exoplanet itself. Dr. Nemati has made pivotal contributions to this mission, including system engineering, selection, modeling and testing of its photon-counting detector, and integrated modeling of the instrument performance.
While Roman CGI will not have the sensitivity to detect exo-Earths, it will serve as the technology steppingstone for the upcoming missions that will. In 2020 Dr. Nemati authored a major paper on how to architect the system engineering of the exo-Earth imaging space telescopes.
For the past year, Dr. Nemati has been pleased to have Dr. Guillermo Gonzalez join and collaborate with him at the University of Alabama.