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    Re: Eclipses of Jupiter's moons: Did ships tend to carry the requisite equipment?
    From: George Huxtable
    Date: 2004 Feb 17, 21:35 +0000

    Patrick Stanistreet wrote-
    >I plan on testing the method of Jupiters moons, at 4 am
    >this morning about 60 miles north of Los Angeles, CA
    >I could see three moons for about 30 minutes then clouds
    >rolled in ending the observations. My telescope is
    >rather small so I wont be going for much accuracy.
    >Since I dont have any tables I tried a search on
    >google using jupiter moons ephemeris
    >First link was helpful
    >    http://ephemeris.sjaa.net/0206/d.html
    >He had a link to some tables and source code which I have
    >not tested at this time but will be using the tables to
    >time events.
    >    http://www.projectpluto.com/jevent.htm
    >I am curious what type of  data appears in George Huxtable's
    >almanac of 1864 as compared to the tables at projectpluto.
    The 1864 almanac gives times of events for the first 3 satellites. The
    events that are tabulated are-
    Eclipse (disappearance or reappearance), occultation (ingress or egress),
    transit (ingress or egress), transit of shadow (ingress or egress).
    Greenwich Mean times are given to the nearest minute except for the
    eclipses, which are timed to a tenth of a second.
    Of course, only a fraction of those tabulated events are visible from a
    particular location.
    As for modern predictions, as I remember the Astronomical Ephemeris
    provides predictions of Jupiter satellite events, but only to the nearest
    minute. Paris is the natural home of accurate timing, and there's an annual
    publication, produced in Paris (in French and English), giving very precise
    predicted times for all these events. The website that Steven Wepster has
    identified may provide that same data, as I recognise in its address the
    initials bdl.fr (presumably "bureau des longitudes.france").
    I wish for clear skies for Patrick,
    contact George Huxtable by email at george@huxtable.u-net.com, by phone at
    01865 820222 (from outside UK, +44 1865 820222), or by mail at 1 Sandy
    Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.

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