Observational Constraints on Water Sublimation from 24 Themis and 1 Ceres

Abstract

Recent observations have suggested that there is water ice present on the surfaces of 24 Themis and 1 Ceres. We present upper limits on the H${}_2$O production rate on these bodies derived using a search for [OI]6300 Angstrom emission. For Themis, the water production is less than 4.5 $\times$ 10${}^{27}$ mol s${}^{-1}$, while for Ceres our derived upper limit is 4.6 $\times$ 10${}^{28}$ mol s${}^{-1}$. The derived limits imply a very low fraction of the surface area of each asteroid is active ($<$ 2 $\times$ 10${}^{-4}$), though this estimate varies by as much as an order of magnitude depending on thermal properties of the surface. This is much lower than seen for comets, which have active areas of 10${}^{-2}$ - 10${}^{-1}$. We discuss possible implications for our findings on the nature of water ice on Themis and Ceres.

arXiv comment15 pages, 3 figures, accepted for publication in Icarus

References in corpus (18)

• A photometricity and extinction monitor at the Apache Point Observatory
• Main Belt Asteroids with WISE/NEOWISE I: Preliminary Albedos and Diameters
• Asteroid thermophysical modeling
• Collisional Excavation of Asteroid (596) Scheila
• The Return of Activity in Main-Belt Comet 133P/Elst-Pizarro
• The Extraordinary Multi-Tailed Main-Belt Comet P/2013 P5
• Testing the comet nature of main belt comets. The spectra of 133P/Elst-Pizarro and 176P/LINEAR
• Main-Belt Comet 238P/Read Revisited
• The Evolving Activity of the Dynamically Young Comet C/2009 P1 (Garradd)
• Identification of Magnetite in B-type Asteroids
• Evolution of H${}_2$O, CO, and CO${}_2$ Production in Comet C/2009 P1 Garradd During the 2011-2012 Apparition
• Limits to Ice on Asteroids (24) Themis and (65) Cybele
• Sublimation-Driven Activity in Main-Belt Comet 313P/Gibbs
• An upper limit for the water outgassing rate of the main-belt comet 176P/LINEAR observed with Herschel/HIFI
• Asteroid Photometry
• The activity of Main Belt comets
• Cometary Science with the James Webb Space Telescope
• New Active Asteroid 313P/Gibbs

Cited by in corpus (6)

• The Peculiar Volatile Composition of CO-Dominated Comet C/2016 R2 (PanSTARRS)
• The Main Belt Comets and Ice in the Solar System
• Asteroid Family Associations of Active Asteroids
• JWST near-infrared spectroscopy of the Lucy Jupiter Trojan flyby targets: Evidence for OH absorption, aliphatic organics, and CO${}_2$
• SAFARI: Searching Asteroids For Activity Revealing Indicators
• Search for Dust Emission from (24) Themis Using the Gemini-North Telescope