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 May 23 [2]See Explanation. Clicking on the picture will download the highest resolution version available. NGC 6366 vs 47 Ophiuchi Image Credit & [3]Copyright: [4]Massimo Di Fusco Explanation: Most [5]globular star clusters roam the halo of our Milky Way galaxy, but globular cluster NGC 6366 lies close to the [6]galactic plane. About 12,000 light-years away toward the constellation Ophiuchus, the cluster's starlight is dimmed and reddened by the Milky Way's interstellar dust when viewed from planet Earth. As a result, the [7]stars of NGC 6366 look almost golden in [8]this telescopic scene, especially when seen next to relatively bright, bluish, and nearby star 47 Ophiuchi. Compared to the hundred thousand stars or so gravitationally bound in distant NGC 6366, 47 Oph itself is a binary star system a mere 100 light-years away. Still, the [9]co-orbiting stars of 47 Oph are too close together to be individually distinguished in the image. Tomorrow's picture: Deimos before sunrise __________________________________________________________________ [10]< | [11]Archive | [12]Submissions | [13]Index | [14]Search | [15]Calendar | [16]RSS | [17]Education | [18]About APOD | [19]Discuss | [20]> __________________________________________________________________ Authors & editors: [21]Robert Nemiroff ([22]MTU) & [23]Jerry Bonnell ([24]UMCP) NASA Official: Amber Straughn [25]Specific rights apply. [26]NASA Web Privacy Policy and Important Notices A service of: [27]ASD at [28]NASA / [29]GSFC, [30]NASA Science Activation & [31]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2505/NGC6366_3500.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://app.astrobin.com/u/massimo.difusco#gallery 5. https://science.nasa.gov/universe/star-clusters-inside-the-universes-stellar-collections/#hds-sidebar-nav-1 6. https://apod.nasa.gov/apod/ap250512.html 7. https://ui.adsabs.harvard.edu/abs/2015A&A...584A..59S/abstract 8. https://app.astrobin.com/i/j2ukh3 9. https://ui.adsabs.harvard.edu/abs/2015AJ....149..110W/abstract 10. https://apod.nasa.gov/apod/ap250522.html 11. https://apod.nasa.gov/apod/archivepix.html 12. https://apod.nasa.gov/apod/lib/apsubmit2015.html 13. https://apod.nasa.gov/apod/lib/aptree.html 14. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 15. https://apod.nasa.gov/apod/calendar/allyears.html 16. https://apod.nasa.gov/apod.rss 17. https://apod.nasa.gov/apod/lib/edlinks.html 18. https://apod.nasa.gov/apod/lib/about_apod.html 19. http://asterisk.apod.com/discuss_apod.php?date=250523 20. https://apod.nasa.gov/apod/ap250524.html 21. http://www.phy.mtu.edu/faculty/Nemiroff.html 22. http://www.phy.mtu.edu/ 23. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 24. http://www.astro.umd.edu/ 25. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 26. https://www.nasa.gov/about/highlights/HP_Privacy.html 27. https://astrophysics.gsfc.nasa.gov/ 28. https://www.nasa.gov/ 29. https://www.nasa.gov/centers/goddard/ 30. https://science.nasa.gov/learners 31. http://www.mtu.edu/