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 September 26 [2]See Explanation. Clicking on the picture will download the highest resolution version available. The Great Globular Cluster in Hercules Image Credit & [3]Copyright: [4]Jan Beckmann, Julian Zoller, Lukas Eisert, Wolfgang Hummel Explanation: [5]In 1716, English astronomer [6]Edmond Halley noted, "This is but a little Patch, but it shows itself to the naked Eye, when the Sky is serene and the Moon absent." [7]Of course, M13 is now less modestly recognized as the Great Globular Cluster in Hercules, one of the brightest [8]globular star clusters in the northern sky. Sharp telescopic views like this one reveal the spectacular cluster's [9]hundreds of thousands of stars. At a distance of 25,000 light-years, the [10]cluster stars crowd into a region 150 light-years in diameter. [11]Approaching the cluster core, upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison, the [12]closest star to the Sun is over 4 light-years away. The deep, wide-field image also reveals distant background galaxies including NGC 6207 at the upper left, and faint, foreground Milky Way dust clouds known to some as [13]integrated flux nebulae. Tomorrow's picture: in the local universe __________________________________________________________________ [14]< | [15]Archive | [16]Submissions | [17]Index | [18]Search | [19]Calendar | [20]RSS | [21]Education | [22]About APOD | [23]Discuss | [24]> __________________________________________________________________ Authors & editors: [25]Robert Nemiroff ([26]MTU) & [27]Jerry Bonnell ([28]UMCP) NASA Official: Phillip Newman [29]Specific rights apply. [30]NASA Web Privacy Policy and Important 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/2409/M13IFN_2048.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://www.distant-luminosity.com/about.html 5. http://messier.seds.org/xtra/similar/halley_pt.html 6. http://www.bbc.co.uk/history/historic_figures/halley_edmond.shtml 7. http://messier.seds.org/m/m013.html 8. http://en.wikipedia.org/wiki/Globular_cluster 9. https://skyandtelescope.org/observing/gobs-of-globs-guide-to-16-spring-globular-clusters/ 10. https://hubblesite.org/contents/news-releases/2008/news-2008-40.html 11. https://apod.nasa.gov/apod/ap031213.html 12. https://apod.nasa.gov/apod/ap160825.html 13. https://apod.nasa.gov/apod/ap240831.html 14. https://apod.nasa.gov/apod/ap240925.html 15. https://apod.nasa.gov/apod/archivepix.html 16. https://apod.nasa.gov/apod/lib/apsubmit2015.html 17. https://apod.nasa.gov/apod/lib/aptree.html 18. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 19. https://apod.nasa.gov/apod/calendar/allyears.html 20. https://apod.nasa.gov/apod.rss 21. https://apod.nasa.gov/apod/lib/edlinks.html 22. https://apod.nasa.gov/apod/lib/about_apod.html 23. http://asterisk.apod.com/discuss_apod.php?date=240926 24. https://apod.nasa.gov/apod/ap240927.html 25. http://www.phy.mtu.edu/faculty/Nemiroff.html 26. http://www.phy.mtu.edu/ 27. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 28. http://www.astro.umd.edu/ 29. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 30. https://www.nasa.gov/about/highlights/HP_Privacy.html 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/