A University of Iowa researcher has been awarded funding from NASA to create an interstellar map that could lead to more accurate observations of planets located outside our solar system — known as exoplanets — and their host stars. 

David Nataf, assistant professor in the Department of Physics and Astronomy, is the lead investigator on the research, which would yield detailed maps to improve the study of exoplanets whose locations are obscured by “interstellar extinction” — the dimming and reddening of stars’ and galaxies’ light due to dust. Specifically, Nataf’s research will focus on learning the properties of host stars, which include mass, distance, metallicity, and temperature. Understanding host stars’ properties is crucial because they shape the characteristics of exoplanets, helping researchers better understand them.

Nataf will use as a primary resource NASA's Nancy Grace Roman Space Telescope, scheduled to launch in 2027, to observe a star- and dust-dense region some 26,000 light-years from Earth along the galactic plane — an imaginary plane that slices the Milky Way galaxy in half. He will combine those observations with data from several other telescopes, including NASA’s Hubble Space Telescope, the joint NASA-European Space Agency Euclid Space Telescope, and the Rubin Observatory.

From those observations, Nataf plans to create a three-dimensional map to show how dust occurs along different lines of sight. Additionally, the interstellar dust map will chart three directions that combined will show how two stars that appear to be close together can be at different depths in space. 

Gravitational lensing — when a massive object, such as a star, warps space and time, causing light to deflect or bend — also will be employed to locate exoplanets. Researchers will examine the movement of stars and see how their brightness against background stars changes over time to more accurately determine exoplanets’ locations.

There are about 6,000 known exoplanets, according to NASA. Thousands more candidate planets await confirmation, and each confirmed planet enables scientists to learn more about the conditions under which planets can form, how common planets like Earth might be, and where to look for them.

“We’ve long looked up at the stars and wondered if there are other worlds like our own,” Nataf says. “With the data from this survey, we’ll be able to say how common planets like Earth are, as in planets with a mass around that of Earth’s, and with a surface effective temperature a little warmer than the freezing point of water. That matters because life as we know it requires liquid water.” 

The three-year NASA award is for $313,000.