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. 2025 September 5 [2]See Explanation. Clicking on the picture will download the highest resolution version available. 47 Tucanae: Globular Star Cluster Image Credit & [3]Copyright: [4]Carlos Taylor Explanation: Also [5]known as NGC 104, 47 Tucanae is a jewel of the southern sky. Not a star but a dense cluster of stars, it roams the halo of our Milky Way Galaxy along with some 200 other [6]globular star clusters. The second brightest globular cluster (after [7]Omega Centauri) as seen from planet Earth, 47 Tuc lies about 13,000 light-years away. It can be spotted with the naked eye close on the sky to the [8]Small Magellanic Cloud in the constellation of [9]the Toucan. The dense cluster is made up of hundreds of thousands [10]of stars in a volume only about 120 light-years across. [11]Red giant stars on the outskirts of the cluster are easy to pick out as yellowish stars in this [12]sharp telescopic portrait. Tightly packed globular star cluster 47 Tuc is also home to a star with the closest known [13]orbit around a black hole. Tomorrow's picture: sea and skyscape __________________________________________________________________ [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: Amber Straughn [29]Specific rights apply. [30]NASA Web Privacy, [31]Accessibility, [32]Notices; A service of: [33]ASD at [34]NASA / [35]GSFC, [36]NASA Science Activation & [37]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2509/crtastro_0352.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://app.astrobin.com/u/CAPastrophotography#gallery 5. http://www.messier.seds.org/xtra/ngc/n0104.html 6. http://en.wikipedia.org/wiki/Globular_cluster 7. https://apod.nasa.gov/apod/ap230316.html 8. https://apod.nasa.gov/apod/ap100903.html 9. http://www.ianridpath.com/startales/tucana.html 10. https://apod.nasa.gov/apod/ap080906.html 11. https://apod.nasa.gov/apod/ap081218.html 12. https://app.astrobin.com/u/CAPastrophotography?i=y6g3ax#gallery 13. https://www.nasa.gov/mission_pages/chandra/news/star-discovered-in-closest-known-orbit-around-likely-black-hole.html 14. https://apod.nasa.gov/apod/ap250904.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.com/feed.rss 21. https://apod.nasa.gov/apod/lib/edlinks.html 22. https://apod.nasa.gov/apod/lib/about_apod.html 23. https://asterisk.apod.com/discuss_apod.php?date=250905 24. https://apod.nasa.gov/apod/ap250906.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://www.nasa.gov/general/accessibility/ 32. https://www.nasa.gov/privacy/ 33. https://astrophysics.gsfc.nasa.gov/ 34. https://www.nasa.gov/ 35. https://www.nasa.gov/centers/goddard/ 36. https://science.nasa.gov/learners 37. http://www.mtu.edu/