English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Photometric Analyses of Saturn's Small Moons: Aegaeon, Methone, and Pallene Are Dark; Helene and Calypso Are Bright

Hedman, M. M., Helfenstein, P., Chancia, R. O., Thomas, P., Roussos, E., Paranicas, C., et al. (2020). Photometric Analyses of Saturn's Small Moons: Aegaeon, Methone, and Pallene Are Dark; Helene and Calypso Are Bright. Astronomical Journal, 159(4): 129. doi:10.3847/1538-3881/ab659d.

Item is

Basic

show hide
Item Permalink: http://hdl.handle.net/21.11116/0000-0006-F516-D Version Permalink: http://hdl.handle.net/21.11116/0000-0006-F517-C
Genre: Journal Article

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Hedman, M. M., Author
Helfenstein, P., Author
Chancia, R. O., Author
Thomas, P., Author
Roussos, Elias1, Author              
Paranicas, C., Author
Verbiscer, A. J., Author
Affiliations:
1Department Planets and Comets, Max Planck Institute for Solar System Research, Max Planck Society, ou_1832288              

Content

show
hide
Free keywords: -
 Abstract: We examine the surface brightnesses of Saturn's smaller satellites using a photometric model that explicitly accounts for their elongated shapes and thus facilitates comparisons among different moons. Analyses of Cassini imaging data with this model reveal that the moons Aegaeon, Methone, and Pallene are darker than one would expect given trends previously observed among the nearby mid-sized satellites. On the other hand, the trojan moons Calypso and Helene have substantially brighter surfaces than their co-orbital companions Tethys and Dione. These observations are inconsistent with the moons' surface brightnesses being entirely controlled by the local flux of E-ring particles, and therefore strongly imply that other phenomena are affecting their surface properties. The darkness of Aegaeon, Methone, and Pallene is correlated with the fluxes of high-energy protons, implying that high-energy radiation is responsible for darkening these small moons. Meanwhile, Prometheus and Pandora appear to be brightened by their interactions with the nearby dusty F ring, implying that enhanced dust fluxes are most likely responsible for Calypso's and Helene's excess brightness. However, there are no obvious structures in the E ring that would preferentially brighten these two moons, so there must either be something subtle in the E-ring particles' orbital properties that leads to asymmetries in the relevant fluxes, or something happened recently to temporarily increase these moons' brightnesses.

Details

show
hide
Language(s): eng - English
 Dates: 2020
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: Peer
 Identifiers: DOI: 10.3847/1538-3881/ab659d
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Astronomical Journal
  Other : Astron. J.
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Chicago : Published by the University of Chicago Press for the American Astronomical Society
Pages: - Volume / Issue: 159 (4) Sequence Number: 129 Start / End Page: - Identifier: ISSN: 0004-6256
CoNE: https://pure.mpg.de/cone/journals/resource/954922828207