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.

                               2024 October 31
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                       Rigel and the Witch Head Nebula
                Image Credit & [3]Copyright: [4]Simone Curzi

   Explanation: By starlight, this eerie visage shines in the dark with a
   crooked profile evoking its popular name, the [5]Witch Head Nebula. In
   fact, this entrancing [6]telescopic portrait gives the impression that
   a witch has fixed her gaze on Orion's bright supergiant [7]star Rigel.
   More formally known as [8]IC 2118, the Witch Head Nebula spans about 50
   light-years and is composed of interstellar dust grains reflecting
   [9]Rigel's starlight. The color of the Witch Head Nebula is caused not
   only by Rigel's intense blue light, but because the [10]dust grains
   scatter blue light more efficiently than red. The same [11]physical
   process causes [12]Earth's daytime sky to appear blue, although the
   scatterers in Earth's atmosphere are molecules of nitrogen and oxygen.
   Rigel and this dusty cosmic crone are about 800 light-years away. You
   may still see a few witches in your neighborhood tonight though, so
   have a safe and [13]Happy Halloween!

                     Tomorrow's picture: pixels in space
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    Authors & editors: [25]Robert Nemiroff ([26]MTU) & [27]Jerry Bonnell
                                 ([28]UMCP)
          NASA Official: Amber Straughn [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/2410/Strega_apod_3.jpg
   3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
   4. https://www.instagram.com/simone_curzi_skylover/
   5. https://apod.nasa.gov/apod/ap061211.html
   6. https://www.flickr.com/photos/197697877@N05/53527999667/
   7. https://en.wikipedia.org/wiki/Rigel
   8. https://en.wikipedia.org/wiki/IC_2118
   9. https://ui.adsabs.harvard.edu/abs/1997MNRAS.290..521I/abstract
  10. https://astronomy.swin.edu.au/cosmos/d/Dust+Grain
  11. http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/blusky.html
  12. https://spaceplace.nasa.gov/blue-sky/en/
  13. https://science.nasa.gov/exoplanets/immersive/galaxy-of-horrors/
  14. https://apod.nasa.gov/apod/ap241030.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=241031
  24. https://apod.nasa.gov/apod/ap241101.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/