                        Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                              2023 December 10
    A landscape shows tall mountains in the distance and evergreen trees
   nearby. Overhead is a star filled sky, with the stars of the Big Dipper
      easily apparent. A rollover image labels names for the Big Dipper
      stars. Please see the explanation for more detailed information.

                      Big Dipper over Pyramid Mountain
                   Image Credit & Copyright: Steve Cullen

   Explanation: When did you first learn to identify this group of stars?
   Although they are familiar to many people around the world, different
   cultures have associated this asterism with different icons and
   folklore. Known in the USA as the Big Dipper, the stars are part of a
   constellation designated by the International Astronomical Union in
   1922 as the Great Bear (Ursa Major). The recognized star names of these
   stars are (left to right) Alkaid, Mizar/Alcor, Alioth, Megrez, Phecda,
   Merak, and Dubhe. Of course, stars in any given constellation are
   unlikely to be physically related. But surprisingly, most of the Big
   Dipper stars do seem to be headed in the same direction as they plough
   through space, a property they share with other stars spread out over
   an even larger area across the sky. Their measured common motion
   suggests that they all belong to a loose, nearby star cluster, thought
   to be on average only about 75 light-years away and up to 30
   light-years across. The cluster is more properly known as the Ursa
   Major Moving Group. The featured image captured the iconic stars
   recently above Pyramid Mountain in Alberta, Canada.

    Night Sky Network webinar: APOD editor to review coolest space images
                                   of 2023
                       Tomorrow's picture: sun change
     __________________________________________________________________

       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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                      A service of: ASD at NASA / GSFC,
                           NASA Science Activation
                             & Michigan Tech. U.

