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.

                              2024 November 29
    [2]See Explanation. Clicking on the picture will download the highest
                        resolution version available.

                                  Messier 4
                Image Credit & [3]Copyright: [4]Steve Crouch

   Explanation: [5]Messier 4 can be found west of bright red-giant star
   Antares, alpha star of the constellation Scorpius. [6]M4 itself is only
   just visible from dark sky locations, even though the globular cluster
   of 100,000 stars or so is a mere 5,500 light-years away. Still, its
   proximity to prying telescopic eyes makes it a prime target for
   astronomical explorations. Recent studies have included Hubble
   observations of M4's pulsating cepheid variable stars, cooling white
   dwarf stars, and ancient, pulsar orbiting [7]exoplanet PSR B1620-26 b.
   This sharp image was captured with a [8]small telescope on planet
   Earth. At M4's estimated distance it spans about 50 light-years across
   the core of the globular star cluster.

                        Tomorrow's picture: the climb
     __________________________________________________________________

       [9]< | [10]Archive | [11]Submissions | [12]Index | [13]Search |
   [14]Calendar | [15]RSS | [16]Education | [17]About APOD | [18]Discuss |
                                    [19]>
     __________________________________________________________________

    Authors & editors: [20]Robert Nemiroff ([21]MTU) & [22]Jerry Bonnell
                                 ([23]UMCP)
          NASA Official: Amber Straughn [24]Specific rights apply.
              [25]NASA Web Privacy Policy and Important Notices
                A service of: [26]ASD at [27]NASA / [28]GSFC,
                         [29]NASA Science Activation
                           & [30]Michigan Tech. U.

References

   1. https://apod.nasa.gov/apod/archivepix.html
   2. https://apod.nasa.gov/apod/image/2411/m4_STXL16200_RC14_LRGB.jpg
   3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
   4. https://members.pcug.org.au/~stevec/
   5. https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-4/
   6. https://apod.nasa.gov/apod/ap000523.html
   7. https://science.nasa.gov/exoplanet-catalog/psr-b1620-26-b/
   8. http://members.pcug.org.au/~stevec/m4_STXL16200_RC14.htm
   9. https://apod.nasa.gov/apod/ap241128.html
  10. https://apod.nasa.gov/apod/archivepix.html
  11. https://apod.nasa.gov/apod/lib/apsubmit2015.html
  12. https://apod.nasa.gov/apod/lib/aptree.html
  13. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search
  14. https://apod.nasa.gov/apod/calendar/allyears.html
  15. https://apod.nasa.gov/apod.rss
  16. https://apod.nasa.gov/apod/lib/edlinks.html
  17. https://apod.nasa.gov/apod/lib/about_apod.html
  18. http://asterisk.apod.com/discuss_apod.php?date=241129
  19. https://apod.nasa.gov/apod/ap241130.html
  20. http://www.phy.mtu.edu/faculty/Nemiroff.html
  21. http://www.phy.mtu.edu/
  22. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html
  23. http://www.astro.umd.edu/
  24. https://apod.nasa.gov/apod/lib/about_apod.html#srapply
  25. https://www.nasa.gov/about/highlights/HP_Privacy.html
  26. https://astrophysics.gsfc.nasa.gov/
  27. https://www.nasa.gov/
  28. https://www.nasa.gov/centers/goddard/
  29. https://science.nasa.gov/learners
  30. http://www.mtu.edu/