GBT25A-504

GBT chemical survey of the newly discovered interstellar comet 3I/ATLAS

Abstract

Our current understanding of cometary chemical compositions and their connections to protoplanetary chemistry and dynamical processes comes almost entirely from solar system comets. On 1st July 2025, the second interstellar comet, C/2025 ATLAS, was detected and has now been thoroughly confirmed. Detailed observations of this object will provide an extraordinary chance to gather information related to the formation
of an alien planetary system.

We plan to use GBT to achieve the following goals:
1. Determine the chemistry of the interstellar comet and track the links to outburst morphology.
2. Search for chemical species important for life in the newly discovered interstellar comet.
3. Determining the D/H of the interstellar comet.
4. Set up a joint observation with our SMA DDT, ALMA DDT, optical telescopes at Steward Observatory and McDonald Observatory to achieve the multiwavelength coverage for the newly discovered interstellar comet.

Investigators

Name	Institution
Cheng-Han Hsieh *	Yale University; Texas at Austin, University of
Adam McKay
Hector Arce	Yale University
Mark Gurwell	Center for Astrophysics | Harvard & Smithsonian
Darryl Seligman	Yale University; Michigan State University
Chunhua Qi	Boston University; Center for Astrophysics | Harvard & Smithsonian
Bryce Bolin	California Institute of Technology
Malena Rice	Yale University
Anita Cochran	Texas at Austin, University of
Matthew Belyakov	California Institute of Technology
David Trilling	Northern Arizona University
Stella Offner	Center for Astrophysics | Harvard & Smithsonian; Massachusetts at Amherst, University of; Texas at Austin, University of

* indicates the PI