English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We carried out observations of the small jovian satellite Amalthea (J5) as itwas being eclipsed by the Galilean satellites near the 2009 equinox of Jupiterin order to apply the technique of mutual event photometry to the astrometricdetermination of this satellite's position. The observations were carried outduring the period 06/2009-09/2009 from the island of Maui, Hawaii and SidingSpring, Australia with the 2m Faulkes Telescopes North and South respectively.We observed in the near-infrared part of the spectrum using a PanStarrs-Zfilter with Jupiter near the edge of the field in order to mitigate against theglare from the planet. Frames were acquired at rates >1/min during eclipsetimes predicted using recent JPL ephemerides for the satellites. Followingsubtraction of the sky background from these frames, differential aperturephotometry was carried out on Amalthea and a nearby field star. We haveobtained three lightcurves which show a clear drop in the flux from Amalthea,indicating that an eclipse took place as predicted. These were model-fitted toyield best estimates of the time of maximum flux drop and the impact parameter.These are consistent with Amalthea's ephemeris but indicate that Amalthea isslightly ahead of, and closer to Jupiter than, its predicted position byapproximately half the ephemeris uncertainty in these directions. We argue thata ground-based campaign of higher-cadence photometry accurate at the 5% levelor better during the next season of eclipses in 2014-15 should yield positionsto within 0".5 and affect a corresponding improvement in Amalthea's ephemeris.

Observational detection of eclipses of J5 Amalthea by the Galilean satellites