0 Assigned ID: 4821 ----- Attempting Submission 1 (Wed May 24 23:38:24 GMT 2023) ----- HST Phase I Proposal 4821 successfully submitted. Receipt: # 4821-1 ----- Attempting Submission 2 (Wed May 24 23:41:33 GMT 2023) ----- HST Phase I Proposal 4821 successfully submitted. Receipt: # 4821-2 ----- Attempting Submission 3 (Wed May 24 23:51:26 GMT 2023) ----- Trans-Neptunian objects (TNOs) are a diverse population of small icy bodies that orbit the Sun beyond the orbit of Neptune, in the outer reaches of the Solar System. These objects are thought to be remnants from the early stages of the Solar System's development and hold valuable clues about its history and ongoing evolution. The distribution of physical properties of TNOs - colors, orbits, binarity - provide clues to understanding the history of the outer Solar System. We propose to search archival WFC3 and ACS data generated since 2009 to discover ~150 TNOs with equivalent V magnitude of at least 27. These objects will be at all ecliptic latitudes. Our measurement of the size distribution of the excited TNO population will provide strong constraints on the dynamical evolution of the outer Solar System. Anastasia Morgan (PI) is a PhD student at NAU who is co-leading the discovery of ultra-faint TNOs in the JWST (#1568) and HST (#1652) combined study as well as in the JWST archival program (#3701). David Trilling (CoI) has extensive experience with large-scale surveys in the inner and outer Solar System. He participated in the Bernstein et al. HST TNO survey and presently leads the DECam Ecliptic Exploration Program (a NOIRLab/DECam TNO survey). He is also the co-PI of JWST program #1568 and PI of the HST program #1652 combined study as well as the PI of the JWST archival program #3701. Cesar Fuentes (CoI) led several HST archive programs to measure the size distribution of TNOs. Pedro Bernardinelli (CoI) co-led the outer solar system science aspects of the Dark Energy Survey project. Solar System Astronomy 0 Regular false false false false false false SUPPORTED