7 Aug. 2025 – Club Meeting Presentation
— Thursday night, 7:00 – 8:30 p.m.
This free speaker presentation will be offered in-person at the
UNC-Asheville Reuter Center and virtually online. Registration is not required; use this Zoom link to watch the presentation remotely.
Although parking for this meeting at the Reuter Center is free, you must register your vehicle with a “Visitor 5pm – 6am” permit type
at this link. Once registration is complete, visitors will not need to print or display a permit; the new system utilizes camera-based License Plate Recognition technology. All vehicles must park front-end in, so that the license plate is visible.
An Astronomy Guest Speaker Series Event – a collaboration of the Astronomy Club of Asheville and UNC-Asheville
Using JWST Near Infrared Spectrograph Instrument to Study the Volatile Composition of Centaurs
– presented by
Adam McKay, Ph.D.
Appalachian State University
Comets are ice-rich solar system objects that consist of primitive material that is left over from the formation of the solar system 4.6 billion years ago. This makes studies of cometary composition important for understanding the physics and chemistry of the early solar system, the formation of icy and organic material, and the subsequent incorporation of this material into planetary bodies.
Comets also have astrobiological significance as potential sources of Earth’s water and organic material. A key piece to understanding comets is a related class of objects called centaurs. Centaurs are icy bodies that orbit in between the orbits of Jupiter and Neptune and are thought to be migrating inward to become short period comets. Therefore, their volatile composition holds clues to the physics and chemistry of the early solar system as well as the degree of compositional evolution experienced by these short period comets during their journey inward toward warmer regions of the solar system.
However, the large orbital distances of centaurs from the Sun make observations of volatile gases in centaurs challenging. Moreover, the mechanisms driving centaur activity at these large distances are still poorly understood. The launch of the James Webb Space Telescope (JWST) enabled new observational capabilities that can help answer these questions about centaur composition and activity. We observed six active centaurs with the NIRSpec instrument on JWST to characterize their volatile composition, specifically in terms of water (H2O), carbon dioxide (CO2), and carbon monoxide (CO). We will present an overview of results from this program to date, including the first detection of CO2, the first characterization of CO2 and CO jets, and the first detection of isotopologues of CO and CO2 in a centaur.