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    Re: Zodiacal coordinates
    From: Geoffrey Kolbe
    Date: 2012 Sep 17, 09:37 +0100

    Hello Rob
    
    I remember you well, welcome back.
    
    By way of (re)introduction for newer members, Rob is an acknowledged
    expert on delta-T and the intricacies of UTC, UT1, leap seconds and
    all that goes with it. When the subject of leap seconds comes around
    again, as I am sure it will, I look forward to Rob giving us the
    benefit of his profound knowledge on the subject.
    
    Rob is also active historian of astronomy in general, and an active
    sailor too, as I recall.
    
    I well remember Rob's talk on the tobacco boxes of Pieter Holm, given
    to the National Maritime Museum symposium on navigational instruments
    back in 2006.
    
    George Huxtable (with whom I think you have confused me Rob,) is
    unfortunately is no longer with us.
    
    Geoffrey Kolbe
    
    At 08:51 17/09/2012, you wrote:
    >Hi George,
    >
    >I agree - my claim that it was an astrological website was perhaps
    >too hasty. I got this impression from the astrology adverts
    >appearing in the bottom-right corner.
    >
    >It is indeed better described as a website useful to both
    >astronomers AND astrologers.
    >
    >I note that the adopted delta-T value for now (71.7 secs) is
    >slightly too high - a value near 67 secs would be more accurate,
    >though this difference would only affect the moon's longitude by a
    >few arcseconds.
    >
    >To the older list members I should perhaps explain that I am not
    >really 'new' to this list. Many years ago I also contributed to this
    >list but when I stopped receiving postings I assumed that the list
    >had been suspended.
    >
    >I only recently discovered that the list still exists (and is also
    >very much alive).
    >
    >Rob van Gent
    >
    >-----Original Message-----
    >From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Geoffrey Kolbe
    >Sent: 15 September 2012 10:24
    >To: Gent, R.H. van (Rob)
    >Subject: [NavList] Re: Zodiacal coordinates
    >
    >At 15:16 14/09/2012, you wrote:
    > >Hi,
    > >
    > >I am new to this list but perhaps I can help.
    > >
    > >The site you have visited is an astrological website and the celestial
    > >positions are given according to astrological conventions.
    > >
    > >The first number is indeed the degree, followed by the zodiacal sign
    > >(Aries starts at 0, Taurus at 30, Gemini at 60, etc.) and then the
    > >number of arcminutes and arcseconds. The positions are ecliptical and
    > >appear to be tropical.
    > >
    > >The R found at the end of some longitudes indicates that the planet's
    > >motion is retrograde (astrologers find this very important).
    > >
    > >I hope that this helps.
    > >
    > >Rob van Gent
    >
    >Well Rob, this is an ephemeris which is obviously meant to be used
    >for historical research as the validity period is 1600 to 2100.
    >Astronomers at the start of that era would certainly recognize this
    >format for ecliptic longitudes, which is still used by astrologers
    >today, as you correctly say. And today, astrologers do not have much
    >use for ecliptic latitudes (they never did) and most astrologers
    >would probably not know a Right Ascension if it hit them between the
    >eyes. Right Ascension today is (I think) only used by astronomers. I
    >would conclude that this is actually an astronomical almanac,
    >formatted to be useful for historical research.
    >
    >As for it being as astrological website, I struggle to actually find
    >the word "astrology" anywhere on the website!
    >
    >Geoffrey
    >
    >
    >
    >
    >
    >View and reply to this message: http://fer3.com/arc/m2.aspx?i=120607
    
    
    
    
    

       
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