Doris Daou
Program Scientist
Ms. Doris Daou has a background as a Research Astrophysicist. She received her M.Sc. in Astrophysics in 1989 from the Université de Montréal in Canada. Her thesis work focused on, at the time, little known types of stars, the ZZ Ceti Stars, non-radially pulsating White Dwarf Stars.
The pulsating DA white dwarfs, or ZZ Ceti stars, represent one of the most homogeneous class of variable stars. Several investigations over the past decades have shown that the existence of pulsating, DA white dwarfs is restricted to a rather narrow instability strip. And indeed, fast photometric searches for pulsating stars in that class, coupled to statistical studies of the resulting frequency of variable stars, provided strong evidence that the ZZ Ceti stars represent an evolutionary phase through which most, if not all, hydrogen atmosphere white dwarfs are expected to cool.
Our work consisted of the spectrophotometry of a sample of 10 ZZ Ceti stars, obtained with the aim of providing independent estimates of the atmospheric parameters of these stars. This was accomplished by a study of high Balmer lines (Hy-H8), which permitted the separation of surface gravity from effective temperature effects. The observations were analyzed in terms of new grids of synthetic spectra, which incorporate the new occupation probability formalism of Hummer and Mihalas to calculate the atomic level populations. Our work was the first to analyze spectroscopic data to confirm the theory as well as the boundaries of the instability strip blue and red edge.
Ms. Daou lectured as a guest professor in 1996, at Notre Dame University, in Lebanon. She has over 30 years of experience working with NASA and on NASA missions such as the Hubble Space Telescope (HST) and Spitzer Space Telescopes. In 2008, Ms. Daou became the Director for Communications and Outreach at NASA Lunar Science Institute (NLSI). After few years she became the Associate Director of the NASA Solar System Research Virtual Institute (SSERVI).
In 2012, Ms. Daou moved back to NASA headquarters in Washington DC. Ms. Daou is now the program scientist for the "Small Innovative Missions for Planetary Exploration (SIMPLEx)", the Exoplanets Research Program, and the Planetary Science Missions Concept Studies.
Please direct questions or corrections on this page to SARA@nasa.gov
