                        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 January 14
    A bright star is pictured in the center of field filled with glowing
    gas and dust and other, more faint, stars. Please see the explanation
                       for more detailed information.

                  North Star: Polaris and Surrounding Dust
                  Image Credit & Copyright: Davide Coverta

   Explanation: Why is Polaris called the North Star? First, Polaris is
   the nearest bright star toward the north spin axis of the Earth.
   Therefore, as the Earth turns, stars appear to revolve around Polaris,
   but Polaris itself always stays in the same northerly direction --
   making it the North Star. Since no bright star is near the south spin
   axis of the Earth, there is currently no bright South Star. Thousands
   of years ago, Earth's spin axis pointed in a slightly different
   direction so that Vega was the North Star. Although Polaris is not the
   brightest star on the sky, it is easily located because it is nearly
   aligned with two stars in the cup of the Big Dipper. Polaris is near
   the center of the five-degree wide featured image, a digital composite
   of hundreds of exposures that brings out faint gas and dust of the
   Integrated Flux Nebula (IFN) all over the frame. The surface of Cepheid
   Polaris slowly pulsates, causing the famous star to change its
   brightness by a few percent over the course of a few days.

        Today: Zoom APOD Lecture hosted by the Amateur Astronomers of
                           Association of New York
                      Tomorrow's picture: north nebula
     __________________________________________________________________

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

