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.

                                2025 June 27
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                                 Messier 109
                 Image Credit & [3]Copyright: [4]Robert Eder

   Explanation: Big beautiful barred spiral [5]galaxy Messier 109 is the
   109th entry in Charles Messier's famous catalog of bright [6]Nebulae
   and Star Clusters. You can find it just below the Big Dipper's bowl in
   the northern constellation Ursa Major. In fact, [7]bright dipper star
   Phecda, Gamma Ursa Majoris, produces the glare at the upper right
   corner of [8]this telescopic frame. M109's prominent central bar gives
   the galaxy the appearance of the Greek letter "theta", θ, a common
   mathematical symbol representing an angle. M109 spans a very small
   [9]angle in planet Earth's sky though, about 7 arcminutes or 0.12
   degrees. But that small [10]angle corresponds to an enormous 120,000
   light-year diameter at the galaxy's estimated 60 million light-year
   distance. The brightest member of the now [11]recognized Ursa Major
   galaxy cluster, M109 (aka NGC 3992) is joined by [12]spiky foreground
   stars. Three small, fuzzy bluish galaxies also on the scene, identified
   (top to bottom) as UGC 6969, UGC 6940 and UGC 6923, are possibly
   satellite galaxies of the larger barred spiral galaxy Messier 109.

                      Tomorrow's picture: light-weekend
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    Authors & editors: [24]Robert Nemiroff ([25]MTU) & [26]Jerry Bonnell
                                 ([27]UMCP)
          NASA Official: Amber Straughn [28]Specific rights apply.
            [29]NASA Web Privacy, [30]Accessibility, [31]Notices;
                A service of: [32]ASD at [33]NASA / [34]GSFC,
                         [35]NASA Science Activation
                           & [36]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2506/M109_Robert_Eder.jpg
   3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
   4. https://www.astrobin.com/users/Robsi/
   5. https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-109/
   6. http://messier.seds.org/xtra/history/m-cat.html
   7. https://apod.nasa.gov/apod/ap110624.html
   8. https://app.astrobin.com/u/Robsi?i=albk8c#gallery
   9. http://chandra.harvard.edu/photo/scale.html
  10. http://chandra.harvard.edu/photo/scale_distance.html
  11. http://arxiv.org/abs/astro-ph/9608124
  12. https://apod.nasa.gov/apod/ap121013.html
  13. https://apod.nasa.gov/apod/ap250626.html
  14. https://apod.nasa.gov/apod/archivepix.html
  15. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  16. https://apod.nasa.gov/apod/lib/aptree.html
  17. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  18. https://apod.nasa.gov/apod/calendar/allyears.html
  19. https://apod.com/feed.rss
  20. https://apod.nasa.gov/apod/lib/edlinks.html
  21. https://apod.nasa.gov/apod/lib/about_apod.html
  22. https://asterisk.apod.com/discuss_apod.php?date=250627
  23. https://apod.nasa.gov/apod/ap250628.html
  24. http://www.phy.mtu.edu/faculty/Nemiroff.html
  25. http://www.phy.mtu.edu/
  26. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  27. http://www.astro.umd.edu/
  28. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  29. https://www.nasa.gov/about/highlights/HP_Privacy.html
  30. https://www.nasa.gov/general/accessibility/
  31. https://www.nasa.gov/privacy/
  32. https://astrophysics.gsfc.nasa.gov/
  33. https://www.nasa.gov/
  34. https://www.nasa.gov/centers/goddard/
  35. https://science.nasa.gov/learners
  36. http://www.mtu.edu/