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. 2021 April 2 [2]See Explanation. Clicking on the picture will download the highest resolution version available. NGC 3521: Galaxy in a Bubble Image Credit & [3]Copyright: Acquisition - [4]Eric Benson, Processing - [5]Dietmar Hager Explanation: Gorgeous spiral galaxy NGC 3521 is a mere 35 million light-years away, toward the [6]constellation Leo. Relatively bright in planet Earth's sky, NGC 3521 is easily visible in small telescopes but often overlooked by amateur imagers in favor of other Leo spiral galaxies, like [7]M66 and M65. It's hard to overlook in this colorful cosmic portrait , though. Spanning some 50,000 light-years the galaxy sports [8]characteristic patchy, irregular spiral arms laced with dust, pink star forming regions, and clusters of young, blue stars. Remarkably, this deep image also finds NGC 3521 embedded in gigantic bubble-like shells. The shells are likely tidal debris, streams of stars torn from satellite galaxies that have [9]undergone mergers with NGC 3521 in the distant past. Tomorrow's picture: How far light travels over the weekend. __________________________________________________________________ [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: Phillip Newman [25]Specific rights apply. [26]NASA Web Privacy Policy and Important Notices A service of: [27]ASD at [28]NASA / [29]GSFC & [30]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2104/NGC3521-LRGB-1.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. http://www.faintgalaxy.com/ 5. https://www.facebook.com/StargazerObservatory/ 6. http://www.universetoday.com/21173/leo/ 7. https://apod.nasa.gov/apod/ap210320.html 8. https://arxiv.org/abs/1803.03653 9. http://www.cosmotography.com/images/galaxy_formation_and_evolution.html 10. https://apod.nasa.gov/apod/ap210401.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=210402 20. https://apod.nasa.gov/apod/ap210403.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. http://www.mtu.edu/