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.

                              2026 February 13
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                             NGC 147 and NGC 185
                 Image Credit & [3]Copyright: [4]Chuck Ayoub

   Explanation: Dwarf galaxies [5]NGC 147 (left) and [6]NGC 185 stand side
   by side in this deep telescopic portrait. The two are not-often-imaged
   satellite galaxies of M31, the [7]great spiral Andromeda Galaxy, some
   2.5 million light-years away. Their separation on the sky, less than
   one degree across a pretty field of view toward the constellation
   Cassiopeia, translates to only about 35 thousand light-years at
   Andromeda's distance, but Andromeda itself is found well outside this
   frame. Brighter and more famous satellite galaxies of Andromeda, [8]M32
   and M110, are seen much closer to the great spiral. [9]NGC 147 and NGC
   185 have been identified as binary galaxies, forming a gravitationally
   stable binary system. But recently discovered faint [10]dwarf galaxy
   Cassiopeia II also seems to be part of their system, forming a
   gravitationally bound group within Andromeda's intriguing population of
   small [11]satellite galaxies.

                   Tomorrow's picture: floral arrangement
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    Authors & editors: [23]Robert Nemiroff ([24]MTU) & [25]Jerry Bonnell
                                 ([26]UMCP)
          NASA Official: Amber Straughn [27]Specific rights apply.
            [28]NASA Web Privacy, [29]Accessibility, [30]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/2602/N147N185.png
   3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
   4. https://www.youtube.com/chucksastrophotography
   5. https://www.nasa.gov/feature/goddard/caldwell-17
   6. https://www.nasa.gov/feature/goddard/caldwell-18
   7. https://apod.nasa.gov/apod/ap181217.html
   8. https://apod.nasa.gov/apod/ap200925.html
   9. https://ui.adsabs.harvard.edu/abs/2017MNRAS.466.1764H/abstract
  10. https://arxiv.org/abs/1511.08289
  11. https://astrobites.org/2013/01/26/the-curious-case-of-andromedas-satellites/
  12. https://apod.nasa.gov/apod/ap260212.html
  13. https://apod.nasa.gov/apod/archivepix.html
  14. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  15. https://apod.nasa.gov/apod/lib/aptree.html
  16. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  17. https://apod.nasa.gov/apod/calendar/allyears.html
  18. https://apod.com/feed.rss
  19. https://apod.nasa.gov/apod/lib/edlinks.html
  20. https://apod.nasa.gov/apod/lib/about_apod.html
  21. https://asterisk.apod.com/discuss_apod.php?date=260213
  22. https://apod.nasa.gov/apod/ap260214.html
  23. http://www.phy.mtu.edu/faculty/Nemiroff.html
  24. http://www.phy.mtu.edu/
  25. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  26. http://www.astro.umd.edu/
  27. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  28. https://www.nasa.gov/about/highlights/HP_Privacy.html
  29. https://www.nasa.gov/general/accessibility/
  30. https://www.nasa.gov/privacy/
  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/