Astronomy Picture of the Day

   [1]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.

                                2026 March 4
   [2]A starfield is shown with a large circular blue ring in the center.
   In the ring's center is a bright blue spot. Please see the explanation
                       for more detailed information.

                   Shapley 1: An Annular Planetary Nebula
       Image Credit & Copyright: [3]Peter Bresseler; Text: [4]Keighley
         Rockcliffe ([5]NASA [6]GSFC, [7]UMBC [8]CSST, [9]CRESST II)

   Explanation: What’s looking back at you isn’t a cosmic eye, but
   [10]Shapley 1, a beautifully symmetric [11]planetary nebula. Shapley 1,
   also known as the [12]Fine Ring Nebula or [13]PLN 329+2.1, bejewels the
   southern sky constellation of the [14]Carpenter's Square ([15]Norma).
   The nebula is the result of a star near the mass of our Sun [16]running
   out of fuel and shedding its outer layers. Glowing oxygen from those
   expelled layers makes up the circular halo. The bright central point is
   actually a binary: a [17]white dwarf, the remaining stellar core after
   the outer layers are expelled into space, and another star, orbiting
   each other every 2.9 days. Shapley 1’s [18]annular shape is due to our
   [19]top-down view of the system and provides insight into the
   [20]influence of central stars on planetary nebula structures.

                      Tomorrow's picture: sun bubbling
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    Authors & editors: [32]Robert Nemiroff ([33]MTU) & [34]Jerry Bonnell
                                 ([35]UMCP)
          NASA Official: Amber Straughn [36]Specific rights apply.
            [37]NASA Web Privacy, [38]Accessibility, [39]Notices;
                A service of: [40]ASD at [41]NASA / [42]GSFC,
                         [43]NASA Science Activation
                           & [44]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2603/Shapley1_Bresseler_2092.jpg
   3. https://pixlimit.com/
   4. https://kerockcliffe.com/
   5. https://science.gsfc.nasa.gov/sci/bio/keighley.e.rockcliffe
   6. https://www.nasa.gov/goddard/
   7. https://physics.umbc.edu/research/astrophysics/
   8. https://csst.umbc.edu/directory/
   9. https://cresst2.umd.edu/
  10. https://www.eso.org/public/images/potw1131a/
  11. https://esahubble.org/wordbank/planetary-nebula/
  12. https://apod.nasa.gov/apod/ap110816.html
  13. https://apod.nasa.gov/apod/ap951212.html
  14. https://en.wikipedia.org/wiki/Steel_square
  15. https://noirlab.edu/public/education/constellations/norma/
  16. https://science.nasa.gov/missions/hubble/hubble-witnesses-the-final-blaze-of-glory-of-sun-like-stars/
  17. https://imagine.gsfc.nasa.gov/science/objects/dwarfs1.html
  18. https://media1.tenor.com/m/uhwiRs3LAVgAAAAd/beyonce-ring.gif
  19. https://svs.gsfc.nasa.gov/5290/#media_group_374408
  20. https://ui.adsabs.harvard.edu/abs/2012MNRAS.420.2271J/abstract
  21. https://apod.nasa.gov/apod/ap260303.html
  22. https://apod.nasa.gov/apod/archivepix.html
  23. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  24. https://apod.nasa.gov/apod/lib/aptree.html
  25. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  26. https://apod.nasa.gov/apod/calendar/allyears.html
  27. https://apod.com/feed.rss
  28. https://apod.nasa.gov/apod/lib/edlinks.html
  29. https://apod.nasa.gov/apod/lib/about_apod.html
  30. https://asterisk.apod.com/discuss_apod.php?date=260304
  31. https://apod.nasa.gov/apod/ap260305.html
  32. http://www.phy.mtu.edu/faculty/Nemiroff.html
  33. http://www.phy.mtu.edu/
  34. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  35. http://www.astro.umd.edu/
  36. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  37. https://www.nasa.gov/about/highlights/HP_Privacy.html
  38. https://www.nasa.gov/general/accessibility/
  39. https://www.nasa.gov/privacy/
  40. https://astrophysics.gsfc.nasa.gov/
  41. https://www.nasa.gov/
  42. https://www.nasa.gov/centers/goddard/
  43. https://science.nasa.gov/learners
  44. http://www.mtu.edu/