                        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 August 27

                 Dark Dust and Colorful Clouds near Antares
                        Image Credit: David McGarvey

   Explanation: Why is the sky near Antares and Rho Ophiuchi so dusty yet
   colorful? The colors result from a mixture of objects and processes.
   Fine dust illuminated from the front by starlight produces blue
   reflection nebulae. Gaseous clouds whose atoms are excited by
   ultraviolet starlight produce reddish emission nebulae. Backlit dust
   clouds block starlight and so appear dark. Antares, a red supergiant
   and one of the brighter stars in the night sky, lights up the
   yellow-red clouds on the lower left of the featured image. Rho Ophiuchi
   lies at the center of the blue nebula near the top. The distant
   globular cluster M4 is visible to the right of Antares. These star
   clouds are even more colorful than humans can see, emitting light
   across the electromagnetic spectrum.

                     Tomorrow's picture: galaxy portrait
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Phillip Newman Specific rights apply.
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