1998/12/01 by Michael E. Brown, C. Koresko, Geoffrey A. Blake · 1 citation
Physics and Astronomy · #Astro and Planetary Science #Stellar, planetary, and galactic studies #Astrophysics and Star Formation Studies
paper · pdf · doi:10.1086/311741
openalex publication_date 1998/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We report the detection of the 1.5 and 2.0 micrometers absorption bands of water ice in the near-infrared reflection spectrum of Neptune's distant irregular satellite Nereid. The spectrum and albedo of Nereid appear intermediate between those of the Uranian satellites Umbriel and Oberon, suggesting a surface composed of a combination of water ice frost and a dark and spectrally neutral material. In contrast, the surface of Nereid appears dissimilar to those of the outer solar system minor planets Chiron, Pholus, and 1997 CU26. The spectrum thus provides support for the hypothesis that Nereid is a regular satellite formed in a circumplanetary environment rather than a captured object.