                        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 July 8
       A cluster of bright blue stars is seen near the bottom of this
      starfield. Nebula around the stars is blue near the stars but red
    elsewhere. Please see the explanation for more detailed information.

                        The Pleiades in Red and Blue
   Image Credit & Copyright: Ogetay Kayali (Michigan Tech U.) Text: Ogetay
                          Kayali (Michigan Tech U.)

   Explanation: If you have looked at the sky and seen a group of stars
   about the size of the full Moon, that's the Pleiades (M45). Perhaps the
   most famous star cluster in the sky, its brightest stars can be seen
   even from the light-polluted cities. But your unaided eye can also see
   its nebulosity -- the gas and dust surrounding it -- under dark skies.
   However, telescopes can catch even more. The bright blue stars of the
   Pleiades, also known as the Seven Sisters, light up their surrounding
   dust, causing it to appear a diffuse blue that can only be seen under
   long exposures. But that's not all. The cosmic dust appears to stretch
   upward like ethereal arms. And the entire structure is surrounded by a
   reddish glow from the most abundant element in the universe: hydrogen.
   The featured image is composed of nearly 25 hours of exposure and was
   captured last year from Starfront Observatory, in Texas, USA

                Explore Your Universe: Random APOD Generator
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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                             & Michigan Tech. U.

