                        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.

                                 2021 May 10

                       Star Clusters M35 and NGC 2158
      Image Credit & Copyright: CFHT, Coelum, MegaCam, J.-C. Cuillandre
                       (CFHT) & G. A. Anselmi (Coelum)

   Explanation: Clusters of stars can be near or far, young or old,
   diffuse or compact. The featured image shows two quite contrasting open
   star clusters in the same field. M35, on the lower left, is relatively
   nearby at 2800 light years distant, relatively young at 150 million
   years old, and relatively diffuse, with about 2500 stars spread out
   over a volume 30 light years across. Bright blue stars frequently
   distinguish younger open clusters like M35. Contrastingly, NGC 2158, on
   the upper right, is four times more distant than M35, over 10 times
   older, and much more compact. NGC 2158's bright blue stars have
   self-destructed, leaving cluster light to be dominated by older and
   yellower stars. In general, open star clusters are found in the plane
   of our Milky Way Galaxy, and contain anywhere from 100 to 10,000 stars
   -- all of which formed at nearly the same time. Both open clusters M35
   and NGC 2158 can be found together with a small telescope toward the
   constellation of the Twins (Gemini).

                      Tomorrow's picture: beyond uluru
     __________________________________________________________________

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

