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Credit: Dean Rowe      
      
      
Explanation:
Clyde Tombaugh discovered      
planet Pluto in 1930      
while surveying the skies with the 13-inch Lawrence Lowell Telescope.      
      
But the skilled and careful astronomer also went on to discover      
star clusters, comets, asteroids, and clusters of galaxies.      
      
For example, pictured is galactic or      
open star cluster      
Tombaugh 4 in the northern constellation      
Cassiopeia.      
      
Published in 1941, Tombaugh's      
description, based      
on his photographic images from the Lowell 13-inch, indicates the      
cluster is small and faint, and comprised of about 30 stars.      
      
Using the apparent brightness of the cluster stars      
he estimated the distance to be 20 to 30 thousand      
light-years, making Tombaugh 4 over 10 light-years in diameter.      
      
This deep      
color image, made with a modern ccd camera      
and another 13-inch telescope, includes the region's      
foreground stars and faint nebulosities.      
      
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: open cluster - star cluster
Publications with words: open cluster - star cluster
See also:

