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.

                              2021 November 12
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                         M33: The Triangulum Galaxy
               Image Credit & [3]Copyright: [4]Bernard Miller

   Explanation: The small, northern constellation [5]Triangulum harbors
   this magnificent face-on spiral galaxy, M33. Its popular names include
   the Pinwheel Galaxy or just the [6]Triangulum Galaxy. M33 is over
   50,000 light-years in diameter, third largest in the [7]Local Group of
   galaxies after the Andromeda Galaxy (M31), and our own Milky Way.
   [8]About 3 million light-years from the Milky Way, M33 is itself
   thought to be a satellite of the Andromeda Galaxy and [9]astronomers in
   these two galaxies would likely have spectacular views of each other's
   grand spiral star systems. As for the view from planet Earth, [10]this
   sharp image shows off M33's blue star clusters and pinkish [11]star
   forming regions along the galaxy's loosely wound spiral arms. In fact,
   the [12]cavernous NGC 604 is the brightest star forming region, seen
   here at about the 4 o'clock position from the galaxy center. Like M31,
   M33's population of well-measured variable stars have helped make this
   nearby spiral a cosmic yardstick for [13]establishing the distance
   [14]scale of the Universe.

                           Tomorrow's picture: 67P
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    Authors & editors: [26]Robert Nemiroff ([27]MTU) & [28]Jerry Bonnell
                                 ([29]UMCP)
          NASA Official: Phillip Newman [30]Specific rights apply.
              [31]NASA Web Privacy Policy and Important Notices
                A service of: [32]ASD at [33]NASA / [34]GSFC
                           & [35]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2111/M33_PS1_CROP_INSIGHT2048.jpg
   3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
   4. http://azstarman.net/CDK/index.html
   5. http://www.hawastsoc.org/deepsky/tri/index.html
   6. http://messier.seds.org/m/m033.html
   7. http://atlasoftheuniverse.com/localgr.html
   8. https://apod.nasa.gov/apod/ap211106.html
   9. http://arxiv.org/abs/astro-ph?papernum=0506609
  10. http://azstarman.net/CDK/M33_2.htm
  11. https://apod.nasa.gov/apod/ap091017.html
  12. https://esahubble.org/images/opo9627c/
  13. http://adsabs.harvard.edu/cgi-bin/bib_query?1926ApJ....63..236H
  14. http://antwrp.gsfc.nasa.gov/diamond_jubilee/debate96.html
  15. https://apod.nasa.gov/apod/ap211111.html
  16. https://apod.nasa.gov/apod/archivepix.html
  17. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  18. https://apod.nasa.gov/apod/lib/aptree.html
  19. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  20. https://apod.nasa.gov/apod/calendar/allyears.html
  21. https://apod.nasa.gov/apod.rss
  22. https://apod.nasa.gov/apod/lib/edlinks.html
  23. https://apod.nasa.gov/apod/lib/about_apod.html
  24. http://asterisk.apod.com/discuss_apod.php?date=211112
  25. https://apod.nasa.gov/apod/ap211113.html
  26. http://www.phy.mtu.edu/faculty/Nemiroff.html
  27. http://www.phy.mtu.edu/
  28. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  29. http://www.astro.umd.edu/
  30. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  31. https://www.nasa.gov/about/highlights/HP_Privacy.html
  32. https://astrophysics.gsfc.nasa.gov/
  33. https://www.nasa.gov/
  34. https://www.nasa.gov/centers/goddard/
  35. http://www.mtu.edu/