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.

                               2019 December 7

                                Lines of Time
                   Image Credit & Copyright: Anton Komlev

   Explanation: In time stars trace lines through the night sky on a
   rotating planet. Taken over two hours or more, these digitally added
   consecutive exposures were made with a camera and wide angle lens fixed
   to a tripod near Orel farm, Primorsky Krai, Russia, planet Earth. The
   stars trail in concentric arcs around the planet's south celestial pole
   below the scene's horizon, and north celestial pole off the frame at
   the upper right. Combined, the many short exposures also bring out the
   pretty star colours. Bluish trails are from stars hotter than Earth's
   Sun, while yellowish trails are from cooler stars. A long time ago this
   tree blossomed, but now reveals the passage of time in the wrinkled and
   weathered lines of its remains.

                     Tomorrow's picture: lines in space
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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