Page:  of 52323
 

PROPER MOTION

in astronomy, apparent movement of a star on the celestial sphere, usually measured as seconds of arc per year; it is due both to the actual relative motions of the sun and the star through space. Proper motion reflects only transverse motion, i.e., the component of motion across the line of sight to the star; it does not include the component of motion toward or away from the sun. The most distant stars show the least proper motion. Barnard's Star, one of the closest stars, has the largest measured proper motion, 10.27 sec of arc per year. The average proper motion of the stars that can be seen with the naked eye is 0.1″ per year.

____________________

The Columbia Encyclopedia, Sixth Edition Copyright© 2004, Columbia University Press. Licensed from Lernout & Hauspie Speech Products N.V. All rights reserved.

-38855-

Questia Media America, Inc. www.questia.com

Publication Information: Encyclopedia Article Title: Proper Motion. Encyclopedia Title: The Columbia Encyclopedia, Sixth Edition. Publisher: Columbia University Press. Place of Publication: New York. Publication Year: 2004.
This feature allows you to create and manage separate folders for your different research projects. To view markups for a different project, make that project your current project.
This feature allows you to save a link to the publication you are reading or view all the publications you have put on your bookshelf.
This feature allows you to save a link to the page you are reading, which you can later return to from Projects.
This feature allows you to highlight words or phrases on the publication page you are reading.
This feature allows you to save a note you write on the publication page you are reading.
This feature allows you to create a citation to the page you are reading that you can paste into your paper. Highlight a passage to include that passage as a quotation.
This feature allows you to save a reference to a publication you are reading for your bibliography or generate a bibliography you can paste into your paper.
This feature allows you to print a range of pages or a single page from the item you are reading, including your notes or highlights (IE users must have "print background colors and image" setting selected.)
This feature allows you to look up words in a dictionary, thesaurus or encyclopedia.
  About Questia Tools
Close Window  
Questia's powerful research tools allow you to highlight, take notes, bookmark and even create instant citations and bibliographies. To use these features and save hours of work, you must be a subscriber to the Questia service.
Need a Questia account?
Choose a subscription plan to save tons of time, stress and hassle, and experience faster, easier research.

» Click here for our subscription plans

Already have a Questia account? Login now!
Error
Working...
Choose one of the options for printing:
Print this page (No Charge)
Print pages to *
Print pages to *
Quick Print Center
View Shopping Cart
*charges may apply