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: Star to star relationships
    From: Peter Monta
    Date: 2016 Sep 27, 11:21 -0700
    Frank Reed writes:


    Don't forget Arcturus! :)


    Or, to give the star its currently-accepted IAU name, "herbertprinz".  The astrology literature is being updated accordingly.

    Mark Coady writes:

    I forgot all about that expanding/contracting universe theory stuff about stars moving with respect to each other

    I was about to write that I don't think the Hubble flow has a direct impact on reference frames; but then again, what about our small motion with respect to the CMB frame (dipole)?  Should the aberration resulting from that be included willy-nilly in the ICRS?  It's a bit parochial that ICRS should include it; instead the ICRS definition should be with respect to the CMB frame, and users should compute the correction for situations like the Solar System barycenter frame or other frames.

    Another star-position modifier is gravity (deflection of starlight), but it is very small, way too small to be of interest to sextant users.  Missions like Gaia must take it into account, though, certainly for the Sun and the large planets.

    Cheers,
    Peter

       
    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