Work

Colors of Faint Jovian and Saturnian Irregular Moons

Year: 2026

Type: article

Abstract: Jupiter and Saturn are encircled by irregular moons that are in orbital groupings. Groups are postulated to be fragments of some parent object—this hypothesis can be probed by studying the moons’ surface properties via their optical colors, which correlate within the orbital families. We used the Caltech HIgh-speed Multi-color camERA (CHIMERA) camera on the Palomar Hale telescope to obtain simultaneous Sloan Digital Sky Survey (SDSS) g - and r -band photometry for a small set of interesting Jovian and Saturnian irregulars. We find colors consistent with literature values for the bright moons Siarnaq and Ananke. Our measurements of the fainter moons Praxidike (Jovian Ananke group) and Saturn’s Mundilfari also match prior measurements. We find Thrymr in Saturn’s Phoebe group to be red, providing additional constraints to two strongly discrepant literature colors. We report g measurements of Kallichore, a potential ESA JUpiter ICy moons Explorer (JUICE) flyby target.

Source: Research Notes of the AAS

DOI: 10.3847/2515-5172/aebd90

Authors: Chantal Hemmann, Brett Gladman, Marina Brozovic, Philip Nicholson, Justine Obidowski

Institutions: University of British Columbia, California Institute of Technology, Cornell University

Language: English

Topic: Astro and Planetary Science

Subfield: Space and Planetary Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: hybrid

OpenAlex ID: W7225835696

FWCI:

Cites: 11

Cited by:

Related to: