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. 2024 February 23 [2]See Explanation. Clicking on the picture will download the highest resolution version available. The Pencil Nebula Supernova Shock Wave Image Credit & [3]Copyright: [4]Helge Buesing Explanation: This supernova shock wave plows through interstellar space at over 500,000 kilometers per hour. Centered and moving upward in the [5]sharply detailed color composite its thin, bright, braided filaments are actually long ripples in a cosmic sheet of glowing gas seen almost edge-on. Discovered in the 1840s by [6]Sir John Herschel, the narrow-looking nebula is sometimes known as Herschel's Ray. [7]Cataloged as NGC 2736, its pointed appearance suggests its modern popular name, the Pencil Nebula. The [8]Pencil Nebula is about 800 light-years away. Nearly 5 light-years long it represents only a small part of the [9]Vela supernova remnant though. The [10]enormous Vela remnant itself is around 100 light-years in diameter, the expanding [11]debris cloud of a star that was seen to [12]explode about 11,000 years ago. Initially, the section of the [13]shock wave seen as the Pencil nebula was moving at millions of kilometers per hour but has slowed considerably, sweeping up surrounding interstellar material. Tomorrow's picture: light-weekend __________________________________________________________________ [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 Policy and Important 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/2402/NGC2736_Helge_Buesing2048.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://www.astrobin.com/users/HelgeBuesing/ 5. https://www.astrobin.com/dl30yu/ 6. https://www.rmg.co.uk/stories/blog/curatorial/remembering-sir-john-fw-herschel-1792-1871 7. https://hubblesite.org/contents/media/images/2003/16/1350-Image.html 8. https://www.youtube.com/watch?v=P4rXhOArFw8 9. https://apod.nasa.gov/apod/ap100910.html 10. https://en.wikipedia.org/wiki/Vela_Supernova_Remnant 11. https://chandra.harvard.edu/xray_sources/supernovas.html 12. https://apod.nasa.gov/apod/ap131001.html 13. https://apod.nasa.gov/apod/ap200202.html 14. https://apod.nasa.gov/apod/ap240222.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.nasa.gov/apod.rss 21. https://apod.nasa.gov/apod/lib/edlinks.html 22. https://apod.nasa.gov/apod/lib/about_apod.html 23. http://asterisk.apod.com/discuss_apod.php?date=240223 24. https://apod.nasa.gov/apod/ap240224.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://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/