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
    Name or NavList Code:
    Email:
       
    Reply
    Re: A halo-like rainbow round the Sun: some sextant measurements.
    From: Tony Oz
    Date: 2017 May 17, 07:13 -0700

    Frank,

    Yes, it was just like the pictured, but only the left bright spot was visible then. I saw them before - several times, - some of them were symmetrical. But I did not have any angle-measuring tool with me and did not notice the colors order.

    Vaguely remembering the "42°" number of the usual rainbow - I expected this halo would be the same. So when I got just 20° - I re-checked the angle several times, it was definitely NOT equal to 22° (or 42° either) - unless I was mising the Sun's center through the denser mist there. Then I got an idea to measure the angular span of the rainbow sector itself - equaling to 0°20'' from red to violet.

    Regards,

    Tony

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

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

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

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

    Email Settings

    NavList ID 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