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.

                               2023 January 30
    [2]A ball of stars containing thousands of stars is shown with mostly
    light colored stars but with some stars having vibrant colors. Please
             see the explanation for more detailed information.

                 Globular Star Cluster NGC 6355 from Hubble
      Image Credit: [3]ESA/[4]Hubble & [5]NASA, [6]E. Noyola, R. Cohen

   Explanation: [7]Globular clusters once ruled the [8]Milky Way. Back in
   the [9]old days, back when our Galaxy first formed, perhaps thousands
   of globular clusters roamed [10]our Galaxy. Today, there are less than
   [11]200 left. Over the eons, many [12]globular clusters were destroyed
   by repeated fateful encounters with each other or the [13]Galactic
   center. Surviving relics are older than any [14]Earth fossil, older
   than any [15]other structures in our Galaxy, and [16]limit the universe
   itself in raw age. There are few, if any, [17]young globular clusters
   left in our [18]Milky Way Galaxy because [19]conditions are not ripe
   for more to form. The [20]featured image shows a Hubble Space Telescope
   view of 13-billion year old [21]NGC 6355, a surviving globular cluster
   currently passing near the [22]Milky Way's center. Globular cluster
   stars are [23]concentrated toward the image center and highlighted by
   bright blue stars. Most other stars in the frame are dimmer, redder,
   and just coincidently lie near the direction to [24]NGC 6355.

                       Tomorrow's picture: tails tales
     __________________________________________________________________

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    Authors & editors: [36]Robert Nemiroff ([37]MTU) & [38]Jerry Bonnell
                                 ([39]UMCP)
          NASA Official: Phillip Newman [40]Specific rights apply.
              [41]NASA Web Privacy Policy and Important Notices
                A service of: [42]ASD at [43]NASA / [44]GSFC,
                         [45]NASA Science Activation
                           & [46]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2301/ngc6355_hubble_3769.jpg
   3. https://esa.int/
   4. https://esahubble.org/
   5. https://www.nasa.gov/
   6. https://www.as.utexas.edu/astronomy/people/?u=102
   7. https://apod.nasa.gov/apod/ap020416.html
   8. https://solarsystem.nasa.gov/resources/285/the-milky-way-galaxy/
   9. https://apod.nasa.gov/apod/ap001029.html
  10. https://apod.nasa.gov/apod/milky_way.html
  11. https://en.wikipedia.org/wiki/Globular_cluster
  12. https://ui.adsabs.harvard.edu/abs/1997ApJ...474..223G/abstract
  13. https://apod.nasa.gov/apod/ap090925.html
  14. https://en.wikipedia.org/wiki/Fossil
  15. https://apod.nasa.gov/apod/ap070930.html
  16. https://map.gsfc.nasa.gov/universe/uni_age.html
  17. https://apod.nasa.gov/apod/ap080806.html
  18. https://www.nasa.gov/mission_pages/sunearth/news/gallery/galaxy-location.html
  19. https://www.nasa.gov/mission_pages/hubble/science/virgo_cluster.html
  20. https://esahubble.org/images/potw2301a/
  21. https://en.wikipedia.org/wiki/NGC_6355
  22. https://apod.nasa.gov/apod/ap180729.html
  23. https://cmg-cmg-tv-10040-prod.cdn.arcpublishing.com/resizer/59uJYA1xkWCYP7fhmbiYheT8rJg=/1440x810/filters:format(jpg):quality(70)/cloudfront-us-east-1.images.arcpublishing.com/cmg/RDRI4ZITA5FPTJFPXBQ7L5YBXM.jpg
  24. https://ui.adsabs.harvard.edu/abs/2023arXiv230105227S/abstract
  25. https://apod.nasa.gov/apod/ap230129.html
  26. https://apod.nasa.gov/apod/archivepix.html
  27. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  28. https://apod.nasa.gov/apod/lib/aptree.html
  29. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  30. https://apod.nasa.gov/apod/calendar/allyears.html
  31. https://apod.nasa.gov/apod.rss
  32. https://apod.nasa.gov/apod/lib/edlinks.html
  33. https://apod.nasa.gov/apod/lib/about_apod.html
  34. http://asterisk.apod.com/discuss_apod.php?date=230130
  35. https://apod.nasa.gov/apod/ap230131.html
  36. http://www.phy.mtu.edu/faculty/Nemiroff.html
  37. http://www.phy.mtu.edu/
  38. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  39. http://www.astro.umd.edu/
  40. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  41. https://www.nasa.gov/about/highlights/HP_Privacy.html
  42. https://astrophysics.gsfc.nasa.gov/
  43. https://www.nasa.gov/
  44. https://www.nasa.gov/centers/goddard/
  45. https://science.nasa.gov/learners
  46. http://www.mtu.edu/