From the July 2013 issue

What do the abbreviations R.A. and Dec. mean, and how do you use them to find objects in the sky?

Michael Stefik, Orland Park, Illinois
By | Published: July 22, 2013 | Last updated on May 18, 2023
Sky coordinates

R.A. means “right ascension” and Dec. means “declination”; these are the two parts of the equatorial coordinate system. Astronomers developed it to correspond to longitude and latitude on Earth.

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