                         Astronomy Picture of the Day

                         Astronomy Picture of the Day

    Discover the cosmos! [1] Each day a different image or photograph of our
 fascinating universe is featured, along with a brief explanation written by a
                           professional astronomer.

                                2018 October 14
                                      [2]
                            Orion in Red and Blue
                Image Credit & Copyright: David Lindemann [3]

Explanation: When did Orion become so flashy? This colorful rendition of part
of the constellation of Orion [4]  comes from red light emitted by hydrogen
[5]  and sulfur [6] (SII), and blue-green light emitted by oxygen [7] (OIII
[8] ). Hues on the featured image [9] were then digitally reassigned to be
indicative of their elemental [10]  origins -- but also striking to the human
eye [11] . The breathtaking composite was painstakingly composed [12]  from
hundreds of images which took nearly 200 hours to collect. Pictured, Barnard's
Loop [13] , across the image bottom, appears to cradle interstellar constructs
including the intricate Orion Nebula [14]  seen just right of center. The
Flame Nebula [15]  can also be quickly located, but it takes a careful eye to
identify the slight indentation of the dark Horsehead Nebula [16] . As to
Orion's flashiness -- a leading explanation for the origin of Barnard's Loop
[17]  is a supernova blast [18]  that occurred about two million years ago.

  Share the Sky: NASA Open API for APOD [19]  Tomorrow's picture: giant eagle

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    Authors & editors: Robert Nemiroff [31] (MTU [32] ) & Jerry Bonnell [33]
                                  (UMCP [34] )
          NASA Official:  Phillip Newman Specific rights apply [35] .
              NASA Web Privacy Policy and Important Notices [36]
              A service of: ASD [37]  at NASA [38]  / GSFC [39]
                           & Michigan Tech. U. [40]
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Site notes:
  [1] archivepix.html
  [2] image/1810/OrionRedBlue_Lindemann_1500.jpg
  [3] http://www.astrobin.com/users/dlindemann/
  [4] ap101023.html
  [5] http://periodic.lanl.gov/1.shtml
  [6] http://periodic.lanl.gov/16.shtml
  [7] http://periodic.lanl.gov/8.shtml
  [8] https://en.wikipedia.org/wiki/Doubly_ionized_oxygen
  [9] http://www.astrobin.com/236167/C/
  [10] http://genesismission.jpl.nasa.gov/educate/scimodule/cosmic/ptable.html
  [11] https://www.youtube.com/watch?v=yzyphSTkW2U
  [12]
http://1.bp.blogspot.com/-9vG8d3-ge14/TkpGlZjif1I/AAAAAAAAAUk/TW7xS5SvY4w/
s1600/cat-puzzle-movement-flop.jpg
  [13] https://en.wikipedia.org/wiki/Barnard%27s_Loop
  [14] ap140325.html
  [15] ap141209.html
  [16] ap150513.html
  [17] http://adsabs.harvard.edu/abs/2011ApJ...733....9O
  [18]
http://www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/
what-is-a-supernova.html
  [19] https://api.nasa.gov/api.html#apod
  [20] ap181013.html
  [21] archivepix.html
  [22] lib/apsubmit2015.html
  [23] lib/aptree.html
  [24] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  [25] calendar/allyears.html
  [26] /apod.rss
  [27] lib/edlinks.html
  [28] lib/about_apod.html
  [29] http://asterisk.apod.com/discuss_apod.php?date=181014
  [30] ap181015.html
  [31] http://www.phy.mtu.edu/faculty/Nemiroff.html
  [32] http://www.phy.mtu.edu/
  [33] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  [34] http://www.astro.umd.edu/
  [35] lib/about_apod.html#srapply
  [36] https://www.nasa.gov/about/highlights/HP_Privacy.html
  [37] https://astrophysics.gsfc.nasa.gov/
  [38] https://www.nasa.gov/
  [39] https://www.nasa.gov/centers/goddard/
  [40] http://www.mtu.edu/
