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 July 19 [2]See Explanation. Clicking on the picture will download the highest resolution version available. Messier 6 Image Credit & [3]Copyright: [4]Xinran Li Explanation: The sixth object in [5]Charles Messier's famous catalog of things which are not comets, Messier 6 is a galactic or [6]open star cluster. A gathering of 100 stars or so, all around 100 million years young, M6 lies some 1,600 light-years away toward the central Milky Way [7]in the constellation Scorpius. Also cataloged as NGC 6405, the pretty star cluster's outline suggests its popular moniker, the [8]Butterfly Cluster. Surrounded by diffuse reddish emission from the region's hydrogen gas the cluster's mostly hot and [9]therefore blue stars are near the center of this colorful cosmic snapshot. But the brightest cluster member is a cool K-type giant star. Designated [10]BM Scorpii it shines with a yellow-orange hue, seen near the end of one of the butterfly's antennae. [11]This telescopic field of view spans nearly 2 Full Moons on the sky. That's 25 light-years at the estimated distance of Messier 6. Tomorrow's picture: light-weekend __________________________________________________________________ [12]< | [13]Archive | [14]Submissions | [15]Index | [16]Search | [17]Calendar | [18]RSS | [19]Education | [20]About APOD | [21]Discuss | [22]> __________________________________________________________________ Authors & editors: [23]Robert Nemiroff ([24]MTU) & [25]Jerry Bonnell ([26]UMCP) NASA Official: Amber Straughn [27]Specific rights apply. [28]NASA Web Privacy, [29]Accessibility, [30]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/2507/M6.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://app.astrobin.com/u/Flying_Dutchman#gallery 5. https://science.nasa.gov/people/explore-the-night-sky-hubbleatms-messier-catalog-bio/ 6. https://earthsky.org/clusters-nebulae-galaxies/m6-and-m7-deep-sky-gems-by-scorpius-tail/ 7. https://science.nasa.gov/image-detail/skychart-scorpiusm6m7-july-2024/ 8. https://en.wikipedia.org/wiki/Butterfly_Cluster 9. https://apod.nasa.gov/apod/ap110211.html 10. https://en.wikipedia.org/wiki/BM_Scorpii 11. https://app.astrobin.com/i/7472xp 12. https://apod.nasa.gov/apod/ap250718.html 13. https://apod.nasa.gov/apod/archivepix.html 14. https://apod.nasa.gov/apod/lib/apsubmit2015.html 15. https://apod.nasa.gov/apod/lib/aptree.html 16. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 17. https://apod.nasa.gov/apod/calendar/allyears.html 18. https://apod.com/feed.rss 19. https://apod.nasa.gov/apod/lib/edlinks.html 20. https://apod.nasa.gov/apod/lib/about_apod.html 21. https://asterisk.apod.com/discuss_apod.php?date=250719 22. https://apod.nasa.gov/apod/ap250720.html 23. http://www.phy.mtu.edu/faculty/Nemiroff.html 24. http://www.phy.mtu.edu/ 25. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 26. http://www.astro.umd.edu/ 27. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 28. https://www.nasa.gov/about/highlights/HP_Privacy.html 29. https://www.nasa.gov/general/accessibility/ 30. https://www.nasa.gov/privacy/ 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/