¿ 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 14 [2]A picture of the Pencil Nebula Supernova Shock Wave For more details, please read the explanation. The Pencil Nebula Supernova Shock Wave Image Credit & Copyright: Greg Turgeon & [3]Utkarsh Mishra Explanation: This supernova shock wave plows through interstellar space at over 500,000 kilometers per hour. Near the middle and moving up in [4]this sharply detailed color composite, thin, bright, braided filaments are actually long ripples in a cosmic sheet of glowing gas seen almost edge-on. Cataloged as [5]NGC 2736, its elongated appearance suggests its popular name, [6]the Pencil Nebula. The [7]Pencil Nebula is about 5 light-years long and 800 [8]light-years away, but represents only a small part of the [9]Vela supernova remnant. The [10]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 [13]shock wave was moving at millions of kilometers per hour but has slowed considerably, sweeping up surrounding interstellar material. In the [14]featured narrow-band, wide field image, red and blue colors track, primarily, the characteristic glows of [15]ionized hydrogen and [16]oxygen atoms, respectively. Portal Universe: [17]Random APOD Generator Tomorrow's picture: open space __________________________________________________________________ [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://apod.nasa.gov/apod/image/2104/Pencil_TurgeonMishra_3930.jpg 3. https://www.utkarshmishraastrophotography.com/ 4. https://www.utkarshmishraastrophotography.com/nebula?pgid=iy1dnzx2-5b74a833-d04e-409a-8eca-5cf22ce304d3 5. https://en.wikipedia.org/wiki/NGC_2736 6. http://www.nasa.gov/vision/universe/starsgalaxies/pencil_nebula.html 7. https://www.youtube.com/watch?v=P4rXhOArFw8 8. https://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html 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://www.utkarshmishraastrophotography.com/nebula?pgid=iy1dnzx2-5b74a833-d04e-409a-8eca-5cf22ce304d3 15. http://astronomy.swin.edu.au/cosmos/i/ionised+hydrogen 16. https://periodic.lanl.gov/8.shtml 17. https://apod.nasa.gov/apod/random_apod.html 18. https://apod.nasa.gov/apod/ap210413.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=210414 28. https://apod.nasa.gov/apod/ap210415.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/