Dr. Adam McKay Contributes to New Study Detecting Carbon Dioxide in Centaurs

BOONE, N.C. — Dr. Adam McKay, assistant professor in the Appalachian State University Department of Physics and Astronomy, is the co-author of a new paper published in the Planetary Science Journal. The study, published in the November 2023 edition of the journal, provides the first detection of carbon dioxide in a class of objects called centaurs.

The study, titled "First Detection of CO2 Emission in a Centaur: JWST NIRSpec Observations of 39P/Oterma," used the National Aeronautics and Space Administration (NASA)'s James Webb Space Telescope (JWST) to obtain infrared spectra of a centaur called 39P/Oterma. Centaurs are ice-rich bodies that orbit the Sun among the outer planets in our solar system, between the orbits of Jupiter and Neptune. These objects are likely transitioning from orbits in the Kuiper Belt (of which Pluto is the most famous member) to short-period comet orbits. This makes them interesting to study because they are primitive leftovers from the formation of the solar system. Since they have spent most of their lives in the cold outer reaches of the solar system, they have undergone less heating from the Sun than short-period comets, which orbit closer to the Earth’s distance from the Sun. Therefore, centaurs can be used as “fossils” or “time capsules” to better understand the earliest days of our solar system, when the planets were first forming.

Since centaurs orbit so far from the Sun, they have been difficult to study pre-JWST. Analyzing the composition of the ices present in these objects has been particularly challenging. However, JWST has made detailed study of these objects possible. Therefore, this work used an instrument on JWST called NIRSpec to obtain spectra of some centaurs to better understand the composition of this icy material. The observations of 39P resulted in the detection of carbon dioxide, an abundant ice in most comets, yet it requires space-based assets like JWST to study because of interference from the Earth’s atmosphere. This work found the first detection of carbon dioxide in a centaur, providing a huge leap forward in the understanding of the compositions of centaurs.

McKay, who is the lead investigator for the JWST program that obtained the data used in this research, published the paper in collaboration with scientists from American University, University of Arizona, University of Central Florida, University of Maryland at College Park, NASA, and the National Science Foundation. The work was led by Dr. Olga Harrington-Pinto, a graduate student at the University of Central Florida at the time and currently a postdoctoral fellow at Auburn University. The work was sponsored by the Space Telescope Space Institute under JWST GO Program 2416.

McKay earned his Ph.D. in Astronomy from New Mexico State University and joined the App State Department of Physics and Astronomy in Fall 2022. His research interests include comets, planet formation and planetary science.


About the Department of Physics and Astronomy
The Department of Physics and Astronomy’s curriculum has an applied nature that includes a core of fundamental physics courses and laboratory experiences. The department prepares graduates for a variety of scientific, teaching or engineering professions, as well as future educational endeavors. Learn more at https://physics.appstate.edu.

By Dr. Adam McKay and Lauren Andersen
December 8, 2023

Dr. Adam McKay, assistant professor in the Appalachian State University Department of Physics and Astronomy
Published: Dec 8, 2023 8:20am