A New Census Of Our Sun’s Neighbors Reveals The Best Potential Real Estate For Life
A new study led by a Georgia State University astronomy graduate student is a major step forward in the search for stars that could host Earth-like planets that may prove to be good havens for life to develop. Sebastián Carrazco-Gaxiola shared the results at the January 2026 meeting of the American Astronomical Society in Phoenix, Ariz.
“This survey marks the first comprehensive look at thousands of the Sun’s lower-mass cousins,” Carrazco-Gaxiola said. “These stars, known as ‘K dwarfs,’ are commonly found throughout space, and they provide a long-term, stable environment for their planetary companions.”
Carrazco-Gaxiola’s survey focuses on over 2,000 stars that are closer than 130 light-years from Earth. The observations are precise measurements of the spectra, or rainbow of colors, emitted by these stars.
The observations were made with state-of-the-art spectrographs on the SMARTS 60-inch mirror telescope at the Cerro Tololo Interamerican Observatory in the Chilean Andes and on the same-sized Tillinghast Telescope at the Fred Lawrence Whipple Observatory in southern Arizona. Together, these two telescopes located in opposite hemispheres allow observations of K-dwarfs across the full sky.
“The CHIRON spectrograph on the SMARTS telescope in Chile and the TRES spectrograph on the Tillinghast Telescope in Arizona are such complementary instruments,” said Allyson Bieryla, an astronomer at the Center for Astrophysics | Harvard & Smithsonian. “The power of having these two telescopes in opposite hemispheres is that it gives us access to all the K-dwarfs across the entire sky.”
Stars come in a wide range of temperatures and masses, and the K dwarf group is slightly cooler and fainter than the Sun. But there are about two times as many K dwarfs compared to Sun-like stars in the “solar neighborhood,” our region in space. They also have much longer lives than Sun-like stars. Any life forms emerging on planets around K dwarfs will enjoy sustaining star-shine almost indefinitely.
Careful analysis of the measurements provides astronomers with estimates of the stars’ temperature, age, spin rate and space motion. In addition, certain colors probe the existence of heated upper layers in the star that are energized by stellar magnetic fields. All of these factors are critical to the environments experienced by planets orbiting the stars.
“This survey will be the foundation for studies of nearby stars for decades to come,” said Distinguished University Professor of Physics and Astronomy Todd Henry, who serves as Carrazco-Gaxiola’s adviser and is a senior author on the study. “These stars and their planets will be the destinations for spacecraft exploration in the far future of space travel.”
Carrazco-Gaxiola’s survey, entitled “An All-Sky Spectroscopic Reconnaissance of More Than 2,100 K Dwarfs Within 40 Parsecs Using High-Resolution Spectra,” is being presented at a press conference at the American Astronomical Society meeting Jan. 6. The presentation features new, unpublished findings that were selected for the AAS press conference due to their broad scientific interest.
This research is funded by the National Science Foundation under grant AST-1910130 and by NASA grant 22-XRP22_2-0187. Institutional support is provided from Georgia State’s College of Arts & Sciences and the Office of the Vice President for Research and Economic Development.
For more information about Georgia State University research and its impact, visit research.gsu.edu.
Astrobiology
