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 October 19
    [2]The picture shows the globular star cluster Palomar 6 as imaged by
       the Hubble Space Telescope. Please see the explanation for more
                            detailed information.

                      Palomar 6: Globular Star Cluster
            Image Credit: [3]ESA/[4]Hubble and [5]NASA, R. Cohen

   Explanation: Where did this big ball of stars come from? [6]Palomar 6
   is one of about 200 [7]globular clusters of stars that survive in
   [8]our Milky Way Galaxy. These spherical star-balls are older than
   [9]our Sun as well as older than most stars that orbit in our
   [10]galaxy's disk. Palomar 6 itself is estimated to be about 12.5
   billion years old, so old that it is close to -- [11]and so constrains
   -- the age of the [12]entire universe. Containing about 500,000 stars,
   [13]Palomar 6 lies about 25,000 [14]light years away, but not very far
   from our [15]galaxy's center. At that distance, [16]this sharp image
   from the [17]Hubble Space Telescope spans about 15 light-years. After
   [18]much study including images from Hubble, a [19]leading origin
   hypothesis is that Palomar 6 was created -- and survives today -- in
   the [20]central bulge of stars that surround the [21]Milky Way's
   center, not in the distant [22]galactic halo where most other
   [23]globular clusters are now found.

                     Tomorrow's picture: lucy in the sky
     __________________________________________________________________

      [24]< | [25]Archive | [26]Submissions | [27]Index | [28]Search |
   [29]Calendar | [30]RSS | [31]Education | [32]About APOD | [33]Discuss |
                                    [34]>
     __________________________________________________________________

    Authors & editors: [35]Robert Nemiroff ([36]MTU) & [37]Jerry Bonnell
                                 ([38]UMCP)
          NASA Official: Phillip Newman [39]Specific rights apply.
              [40]NASA Web Privacy Policy and Important Notices
                A service of: [41]ASD at [42]NASA / [43]GSFC
                           & [44]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2110/Palomar6_Hubble_2529.jpg
   3. https://www.esa.int/
   4. https://esahubble.org/
   5. https://www.nasa.gov/
   6. https://en.wikipedia.org/wiki/Palomar_6
   7. https://en.wikipedia.org/wiki/Globular_cluster
   8. https://imagine.gsfc.nasa.gov/science/objects/milkyway1.html
   9. https://solarsystem.nasa.gov/solar-system/sun/overview/
  10. https://astronomy.swin.edu.au/cosmos/d/Disk+Galaxies
  11. https://wmap.gsfc.nasa.gov/universe/uni_age.html
  12. https://science.nasa.gov/science-news/science-at-nasa/2013/21mar_cmb
  13. https://ui.adsabs.harvard.edu/abs/2021arXiv210904483S/abstract
  14. https://spaceplace.nasa.gov/light-year/en/
  15. https://apod.nasa.gov/apod/ap180729.html
  16. https://esahubble.org/images/potw2138a/
  17. https://www.nasa.gov/mission_pages/hubble/about
  18. https://i.ytimg.com/vi/5sjKUrBsaIE/hqdefault.jpg
  19. https://arxiv.org/pdf/2109.04483.pdf
  20. https://en.wikipedia.org/wiki/Galactic_bulge
  21. https://apod.nasa.gov/apod/ap190708.html
  22. https://en.wikipedia.org/wiki/Stellar_halo
  23. https://apod.nasa.gov/apod/ap190324.html
  24. https://apod.nasa.gov/apod/ap211018.html
  25. https://apod.nasa.gov/apod/archivepix.html
  26. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  27. https://apod.nasa.gov/apod/lib/aptree.html
  28. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  29. https://apod.nasa.gov/apod/calendar/allyears.html
  30. https://apod.nasa.gov/apod.rss
  31. https://apod.nasa.gov/apod/lib/edlinks.html
  32. https://apod.nasa.gov/apod/lib/about_apod.html
  33. http://asterisk.apod.com/discuss_apod.php?date=211019
  34. https://apod.nasa.gov/apod/ap211020.html
  35. http://www.phy.mtu.edu/faculty/Nemiroff.html
  36. http://www.phy.mtu.edu/
  37. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  38. http://www.astro.umd.edu/
  39. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  40. https://www.nasa.gov/about/highlights/HP_Privacy.html
  41. https://astrophysics.gsfc.nasa.gov/
  42. https://www.nasa.gov/
  43. https://www.nasa.gov/centers/goddard/
  44. http://www.mtu.edu/