Welcome to the NavList Message Boards.

NavList:

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

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Venus ex-meridian
    From: Federico Rossi
    Date: 2011 Jan 16, 21:59 +0100

    This morning, after weeks of cloudy weather, a beautiful sun was shining
    over Genoa, Italy so I took my 1940 Plath sextant, reached the shore (44
    25.5 N 8 48.8 E by GPS) which is only 5 minutes away by feet and took my
    first Venus sight in full daylight.
    I preset the sextant to the precomputed altitude and, after some tries,
    I finally spotted Venus with its phase clearly visible through my 3.5 x
    scope.
    Here's what I got:
    08 50 31 UT      Hs 26 37,1    I.C. = 0     elevation 4 meters
    I worked out the sight using the haversine method and Norie's tables (as
    I usually like to do) and found an intercept of 0.8 miles towards (which
    I consider not too bad considering the task of collimating Venus with a
    bright horizon), azimuth being 189,5 by ABC tables.
    Since the hour angle was within ex-meridian limits (8 52.0 W), I decided
    to work the sight as an ex-meridian and found that the position line
    passes through 44 24,5 N 8 48,8 E (in good accordance with the "normal"
    position, but only 0.2 miles towards Venus). Anyway, this ex-meridian
    reduction took almost the same time as the haversine did.......
    
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    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:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    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