¿ 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 11 IFRAME: [2]https://www.youtube.com/embed/Qg6PwRI2uS8?rel=0 When Black Holes Collide Video Credit & Copyright: [3]Simulating Extreme Spacetimes Collaboration Explanation: What happens when two black holes collide? This extreme scenario occurs in the centers of many merging galaxies and multiple star systems. The [4]featured video shows a computer animation of the final stages of such a merger, while highlighting the [5]gravitational lensing effects that would appear on a background [6]starfield. The black regions indicate the [7]event horizons of the [8]dynamic duo, while a surrounding ring of shifting background stars indicates the position of their combined [9]Einstein ring. All background stars not only have [10]images visible outside of this [11]Einstein ring, but also have one or more companion images visible on the inside. Eventually the two [12]black holes [13]coalesce. The end stages of such a merger is now known to produce a strong blast of [14]gravitational radiation, providing a [15]new way to [16]see our universe. This Week is: [17]Black Hole Week at NASA Tomorrow's picture: flame without fire __________________________________________________________________ [18]< | [19]Archive | [20]Submissions | [21]Index | [22]Search | [23]Calendar | [24]RSS | [25]Education | [26]About APOD | [27]Discuss | [28]> __________________________________________________________________ Authors & editors: [29]Robert Nemiroff ([30]MTU) & [31]Jerry Bonnell ([32]UMCP) NASA Official: Phillip Newman [33]Specific rights apply. [34]NASA Web Privacy Policy and Important Notices A service of: [35]ASD at [36]NASA / [37]GSFC & [38]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://www.youtube.com/embed/Qg6PwRI2uS8?rel=0 3. https://www.black-holes.org/about-us/people 4. https://www.youtube.com/watch?v=Qg6PwRI2uS8 5. http://www.cfhtlens.org/public/what-gravitational-lensing 6. https://apod.nasa.gov/apod/ap121015.html 7. https://en.wikipedia.org/wiki/Event_horizon 8. https://www.black-holes.org/explore/movies 9. https://apod.nasa.gov/apod/ap080728.html 10. http://apod.nasa.gov/htmltest/rjn_bht.html 11. https://en.wikipedia.org/wiki/Einstein_ring 12. https://science.nasa.gov/astrophysics/focus-areas/black-holes 13. https://i.pinimg.com/originals/9a/99/ff/9a99ffbcf5491aeaafdcd43c87ede93c.jpg 14. https://ligo.caltech.edu/page/gravitational-waves 15. https://apod.nasa.gov/apod/ap160211.html 16. https://apod.nasa.gov/apod/ap201104.html 17. https://imagine.gsfc.nasa.gov/bhw/ 18. https://apod.nasa.gov/apod/ap210410.html 19. https://apod.nasa.gov/apod/archivepix.html 20. https://apod.nasa.gov/apod/lib/apsubmit2015.html 21. https://apod.nasa.gov/apod/lib/aptree.html 22. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 23. https://apod.nasa.gov/apod/calendar/allyears.html 24. https://apod.nasa.gov/apod.rss 25. https://apod.nasa.gov/apod/lib/edlinks.html 26. https://apod.nasa.gov/apod/lib/about_apod.html 27. http://asterisk.apod.com/discuss_apod.php?date=210411 28. https://apod.nasa.gov/apod/ap210412.html 29. http://www.phy.mtu.edu/faculty/Nemiroff.html 30. http://www.phy.mtu.edu/ 31. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 32. http://www.astro.umd.edu/ 33. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 34. https://www.nasa.gov/about/highlights/HP_Privacy.html 35. https://astrophysics.gsfc.nasa.gov/ 36. https://www.nasa.gov/ 37. https://www.nasa.gov/centers/goddard/ 38. http://www.mtu.edu/