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.

                               2023 October 28
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                           The Ghosts of Gamma Cas
   Image Credit & [3]Copyright: [4]Guillaume Gruntz, [5]Jean-François Bax

   Explanation: [6]Gamma Cassiopeiae shines high in northern autumn
   evening skies. It's the brightest spiky star in this telescopic field
   of view toward the constellation Cassiopeia. [7]Gamma Cas shares the
   ethereal-looking scene with ghostly interstellar clouds of gas and
   dust, IC 59 (top left) and IC 63. About 600 light-years distant, [8]the
   clouds aren't actually ghosts. They are slowly disappearing though,
   eroding under the influence of [9]energetic radiation from hot and
   luminous gamma Cas. [10]Gamma Cas is physically located only 3 to 4
   light-years from the nebulae. Slightly closer to gamma Cas, IC 63 is
   dominated by [11]red H-alpha light emitted as hydrogen atoms ionized by
   the star's ultraviolet radiation recombine with electrons. Farther from
   the star, IC 59 shows proportionally less H-alpha emission but more of
   the characteristic blue tint of dust [12]reflected star light. The
   cosmic stage spans over 1 degree or 10 light-years at the estimated
   distance of [13]gamma Cas and friends.

               Tomorrow's picture: ghosts of the Cepheus Flare
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    Authors & editors: [25]Robert Nemiroff ([26]MTU) & [27]Jerry Bonnell
                                 ([28]UMCP)
          NASA Official: Phillip Newman [29]Specific rights apply.
              [30]NASA Web Privacy Policy and Important Notices
                A service of: [31]ASD at [32]NASA / [33]GSFC,
                         [34]NASA Science Activation
                           & [35]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2310/IC63_GruntzBax.jpg
   3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
   4. https://www.astrobin.com/users/GuillaumeGz/
   5. https://www.astrobin.com/users/jeffbax/
   6. https://www.aavso.org/vsots_gammacas
   7. https://www.astrobin.com/k5f7nk/0/
   8. https://hubblesite.org/contents/news-releases/2018/news-2018-42.html
   9. https://arxiv.org/abs/1809.01419
  10. https://en.wikipedia.org/wiki/Gamma_Cassiopeiae
  11. https://apod.nasa.gov/apod/ap111013.html
  12. https://apod.nasa.gov/apod/ap091126.html
  13. https://arxiv.org/abs/1705.04313
  14. https://apod.nasa.gov/apod/ap231027.html
  15. https://apod.nasa.gov/apod/archivepix.html
  16. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  17. https://apod.nasa.gov/apod/lib/aptree.html
  18. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  19. https://apod.nasa.gov/apod/calendar/allyears.html
  20. https://apod.nasa.gov/apod.rss
  21. https://apod.nasa.gov/apod/lib/edlinks.html
  22. https://apod.nasa.gov/apod/lib/about_apod.html
  23. http://asterisk.apod.com/discuss_apod.php?date=231028
  24. https://apod.nasa.gov/apod/ap231029.html
  25. http://www.phy.mtu.edu/faculty/Nemiroff.html
  26. http://www.phy.mtu.edu/
  27. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  28. http://www.astro.umd.edu/
  29. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  30. https://www.nasa.gov/about/highlights/HP_Privacy.html
  31. https://astrophysics.gsfc.nasa.gov/
  32. https://www.nasa.gov/
  33. https://www.nasa.gov/centers/goddard/
  34. https://science.nasa.gov/learners
  35. http://www.mtu.edu/