Printer Friendly
Dictionary, Encyclopedia and Thesaurus - The Free Dictionary
3,898,166,011 visitors served.
forum Join the Word of the Day Mailing List For webmasters
?
Dictionary/
thesaurus
Medical
dictionary
Legal
dictionary
Financial
dictionary
Acronyms
 
Idioms
Encyclopedia
Wikipedia
encyclopedia
?

Arcturus
(redirected from Alpha Bootis)

   Also found in: Dictionary/thesaurus, Wikipedia 0.01 sec.
Arcturus (ärktr`əs), brightest star in the constellation Boötes Boötes [Gr.,=the herdsman], northern constellation located to the SE of the Big Dipper in Ursa Major and W of Corona Borealis, the Northern Crown. It contains the brilliant orange star Arcturus.
..... Click the link for more information.
 and 4th-brightest star in the entire sky; Bayer designation Alpha Boötis; 1992 position R.A. 14h15.3m, Dec. +19°13'. An orange giant of spectral class spectral class, in astronomy, a classification of the stars by their spectrum and luminosity. In 1885, E. C. Pickering began the first extensive attempt to classify the stars spectroscopically.
..... Click the link for more information.
 K2 III, it has an apparent magnitude magnitude, in astronomy, measure of the brightness of a star or other celestial object. The stars cataloged by Ptolemy (2d cent. A.D.), all visible with the unaided eye, were ranked on a brightness scale such that the brightest stars were of 1st magnitude and the
..... Click the link for more information.
 of −0.06; its diameter is about 10 times that of the sun and its luminosity about 100 times that of the sun. Arcturus is one of the nearest giant stars, at a distance of about 36 light-years, and has one of the largest proper motions 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.
..... Click the link for more information.
 (annual angular shift in position) of the bright stars. Its name is from the Greek meaning "guardian of the bear," and it can be found by following the extension of the curve of the handle of the Big Dipper (Large Bear).
Arcturus [‚ärk′tu̇r·əs]
(astronomy)
A star that is 36 light-years from the sun; spectral classification K2IIIp. Also known as α Boötes.


Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content.
?Page tools
Printer friendly
Cite / link
Feedback
Mentioned in?   Encyclopedia browser?   Full browser?
No references found
 
 
 
Encyclopedia
?

Terms of Use | Privacy policy | Feedback | Advertise with Us | Copyright © 2012 Farlex, Inc.
Disclaimer
All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.