                        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.

                                 2025 June 5

                            Savudrija Star Trails
                    Image Credit & Copyright: Branko Nadj

   Explanation: Savudrija lighthouse shines along the coast near the
   northern end of the Istrian peninsula in this well-composed night
   skyscape. A navigational aid for sailors on the Adriatic Sea, the
   historic lighthouse was constructed in the early 19th century. But an
   even older aid to navigation shines in the sky above, Polaris, alpha
   star of the constellation Ursa Minor and also known as the North Star.
   In this scene Polaris forms the shortest bright arc near the North
   Celestial Pole, the extension of Earth's axis of rotation into space.
   Of course, the North Celestial Pole lies exactly at the center of all
   the concentric startrails. The composite image is a digital stack of
   400 exposures, each 30 seconds long, taken with camera and tripod fixed
   to a rotating planet.

                     Tomorrow's picture: pixels in space
     __________________________________________________________________

       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
                NASA Web Privacy Policy and Important Notices
                      A service of: ASD at NASA / GSFC,
                           NASA Science Activation
                             & Michigan Tech. U.

