From spencer Tue Nov 28 16:48:00 1995
From spencer Tue Nov 28 16:48:00 1995
To: oleroemer
Subject: Io Volcano News
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Status: RO

1. LOKI WAS BRIGHT 25 DAYS BEFORE THE GALILEO ENCOUNTER

Reduction of Io's November 12th Jupiter occultation egress lightcurve,
using the data obtained by Christophe Dumas with NSFCAM at the IRTF,
shows that Loki was undergoing one of its periodic brightenings at that
time: about 2/3 of the total 3.5 micron volcanic flux from Io at egress
was from Loki, despite the fact that Loki was only 30 degrees from Io's
limb at the time, and thus considerably foreshortened.  The lightcurve
does not show the other bright hot spots on the Jupiter-facing
hemisphere that were active in the July - September period: those
eruptions have apparently died down.

It's likely that the Loki brightening is a continuation of the
brightening that started in late August: reduction of existing
unreduced September and October occultation and eclipse data will be
required to confirm this.  With luck, Jay Goguen and I will be able to
determine whether the Loki brightening persists until the Galileo
encounter, using 5 - 20 micron photometry from the IRTF starting on
December 1st.

2. IO WORKSHOP POSTPONED

Due to the lack of remote sensing data from Io at the December
encounter, I am cancelling plans for an Io workshop in Flagstaff
next October.  The amount of Galileo Io data that will have
accumulated by then will be insufficient to justify a workshop.
One will be organised at some later date instead- suggestions and 
comments are welcome.