Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Time of full moon
    From: Antoine Couëtte
    Date: 2019 Dec 14, 05:36 -0800

    Re : Time-full-moon-Hebard-dec-2019-g46393

    Let us first define a "Geocentric Fictitious Sun" as follows :

    Fictitious Sun RA = Apparent Sun RA + 180 °

    Fictitious Sun Dec = Opposite of Apparent Sun Dec

    Fictitious Sun Distance = Equal to Sun Distance.

    We can then define "Full Moon" as being the time of minimum geocentric distance between apparent Moon Center and Fictitious Sun Center. This is not the official definition, but it is at least as good as the official one since it does have a meaningful and solid physical sense and since it also does NOT depend on the coordinates system being used for such computation.

    With :

    TT - UT = +69,55 s

    I find "Full Moon" time as being 2019-Dec-12 at 05h30m39.6 UTC with the Software I am using, i.e with Sun Apparent position Maximum Error 0.3"and Moon Apparent position maximum error.4.5 "

    I trust that with the above definition and given the uncertainties mentioned here-above, the "true" time of full Moon is within +/- 20 seconds of time of the result published hereabove.

    To you Paul Hirose ( Re : Time-full-moon-Hirose-dec-2019-g46404) it might nice to get your own results here if you can easily program such "unorthodox" Full Moon Time Definition from your current software.

    Best Friendly regards to all, with my best wishes for Merry Christmas 2019 and Happy New Year 2020.


    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site