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.

                              2022 December 26
    [2]The featured image shows a star inside a symmetric but complex and
    multi-colored nebula which is all surrounded by a faint blue nebula.
          Please see the explanation for more detailed information.

                   NGC 6164: Dragon's Egg Nebula and Halo
                 Image Credit & Copyright: [3]Russell Croman

   Explanation: The star at the center created everything. Known as the
   [4]Dragon's Egg, this star -- a rare, hot, luminous [5]O-type star some
   40 times as massive as the Sun -- created not only the complex nebula
   ([6]NGC 6164) that immediately surrounds it, but also the encompassing
   blue halo. Its name is derived, in part, from the region's proximity to
   the picturesque NGC 6188, known as the fighting [7]Dragons of Ara. In
   another three to four million years the massive star will likely end
   its life in a [8]supernova explosion. Spanning around 4 light-years,
   [9]the nebula itself has a bipolar symmetry making it similar in
   appearance to more common [10]planetary nebulae - the gaseous shrouds
   [11]surrounding dying sun-like stars. Also like many planetary nebulae,
   NGC 6164 has been found to have an extensive, [12]faint halo, revealed
   in blue in [13]this deep telescopic image of the region. Expanding into
   the surrounding [14]interstellar medium, the material in the blue halo
   was likely expelled from an earlier active phase of the O-star. NGC
   6164 lies 4,200 [15]light-years away in the southern constellation of
   the [16]Carpenter's Square ([17]Norma).

                   Tomorrow's picture: all the way around
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    Authors & editors: [29]Robert Nemiroff ([30]MTU) & [31]Jerry Bonnell
                                 ([32]UMCP)
          NASA Official: Phillip Newman [33]Specific rights apply.
              [34]NASA Web Privacy Policy and Important Notices
                A service of: [35]ASD at [36]NASA / [37]GSFC,
                         [38]NASA Science Activation
                           & [39]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2212/DragonsEgg_Croman_4231.jpg
   3. https://www.rc-astro.com/about.html
   4. https://en.wikipedia.org/wiki/Dragon%27s_Egg
   5. http://www.atlasoftheuniverse.com/startype.html
   6. https://apod.nasa.gov/apod/ap060606.html
   7. https://apod.nasa.gov/apod/ap220607.html
   8. https://imagine.gsfc.nasa.gov/science/objects/supernovae1.html
   9. http://www.gemini.edu/node/188
  10. https://en.wikipedia.org/wiki/Planetary_nebula
  11. https://apod.nasa.gov/apod/ap120831.html
  12. https://ui.adsabs.harvard.edu/abs/1985PASP...97..780F/abstract
  13. https://www.rc-astro.com/photo/id1255_big.html
  14. http://www-ssg.sr.unh.edu/ism/what1.html
  15. https://spaceplace.nasa.gov/light-year/en/
  16. https://en.wikipedia.org/wiki/Steel_square
  17. http://www.hawastsoc.org/deepsky/nor/index.html
  18. https://apod.nasa.gov/apod/ap221225.html
  19. https://apod.nasa.gov/apod/archivepix.html
  20. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  21. https://apod.nasa.gov/apod/lib/aptree.html
  22. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  23. https://apod.nasa.gov/apod/calendar/allyears.html
  24. https://apod.nasa.gov/apod.rss
  25. https://apod.nasa.gov/apod/lib/edlinks.html
  26. https://apod.nasa.gov/apod/lib/about_apod.html
  27. http://asterisk.apod.com/discuss_apod.php?date=221226
  28. https://apod.nasa.gov/apod/ap221227.html
  29. http://www.phy.mtu.edu/faculty/Nemiroff.html
  30. http://www.phy.mtu.edu/
  31. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  32. http://www.astro.umd.edu/
  33. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  34. https://www.nasa.gov/about/highlights/HP_Privacy.html
  35. https://astrophysics.gsfc.nasa.gov/
  36. https://www.nasa.gov/
  37. https://www.nasa.gov/centers/goddard/
  38. https://science.nasa.gov/learners
  39. http://www.mtu.edu/