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
    Re: Polaris in daytime
    From: Greg Rudzinski
    Date: 2012 Jan 25, 06:59 -0800

    Geoffrey,

    I have been able to observe daytime Sirius using a 4 power sextant scope. Since Sirius is 23 times as bright as Polaris then a 92 power scope should do the trick.

    Greg Rudzinski


    [NavList] Polaris in daytime
    From: Geoffrey Kolbe
    Date: 25 Jan 2012 14:31

    Surveyors often need to find true North to lay out the initial
    reference line off which a building is measured. These days, with GPS
    gizmos, there is no difficulty in this. But pre-GPS, true North was
    found by taking a timed azimuth measurement of the sun, or of Polaris
    which, the text books say, is visible during the day using the
    average theodolite 30x scope.

    When I was in Egypt a few years ago doing an experiment on pyramid
    alignment, I tried to find Polaris using my theodolite. I had taken
    azimuth measurements off the sun, so I knew where to look, but I
    never saw nothing. Polaris is too high in these latitudes (Scotland)
    to see with a theodolite, so I am not able to try here.

    Has anyone in lower latitudes managed to see Polaris in the daytime
    through their sextant telescope, or through any other telescope? I
    was wondering how big a telescope you need to see Polaris in the daytime.

    Thanks

    Geoffrey Kolbe

    ----------------------------------------------------------------
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com
    ----------------------------------------------------------------

    File:


       
    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