¿ 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. 2020 November 24 [2]See Explanation. Clicking on the picture will download the highest resolution version available. The Helix Nebula from CFHT Image Credit & Copyright: [3]CFHT, [4]Coelum, [5]MegaCam, [6]J.-C. Cuillandre ([7]CFHT) & [8]G. A. Anselmi ([9]Coelum) Explanation: Will our Sun look like this one day? The [10]Helix Nebula is one of brightest and closest examples of a [11]planetary nebula, a gas [12]cloud created at the end of the life of a Sun-like star. The outer gasses of the star [13]expelled into space appear from our vantage point as if we are looking down a [14]helix. The remnant central stellar core, destined to become a [15]white dwarf star, glows in light so [16]energetic it causes the previously expelled gas to [17]fluoresce. The [18]Helix Nebula, given a technical designation of [19]NGC 7293, lies about 700 [20]light-years away towards the [21]constellation of the Water Bearer ([22]Aquarius) and spans about 2.5 light-years. The [23]featured picture was taken with the [24]Canada-France-Hawaii Telescope (CFHT) located atop a dormant volcano in [25]Hawaii, [26]USA. A [27]close-up of the [28]inner edge of the [29]Helix Nebula shows complex gas knots of [30]unknown origin. Tomorrow's picture: andromedian horizon __________________________________________________________________ [31]< | [32]Archive | [33]Submissions | [34]Index | [35]Search | [36]Calendar | [37]RSS | [38]Education | [39]About APOD | [40]Discuss | [41]> __________________________________________________________________ Authors & editors: [42]Robert Nemiroff ([43]MTU) & [44]Jerry Bonnell ([45]UMCP) NASA Official: Phillip Newman [46]Specific rights apply. [47]NASA Web Privacy Policy and Important Notices A service of: [48]ASD at [49]NASA / [50]GSFC & [51]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2011/Helix2_CFHT_1917.jpg 3. http://www.cfht.hawaii.edu/ 4. http://www.coelum.com/ 5. http://www.cfht.hawaii.edu/Instruments/Imaging/Megacam/ 6. http://www.cfht.hawaii.edu/~jcc/ 7. http://www.cfht.hawaii.edu/ 8. http://www.coelum.com/coelum/autori/giovanni-anselmi 9. http://www.coelum.com/ 10. https://en.wikipedia.org/wiki/Helix_Nebula 11. https://en.wikipedia.org/wiki/Planetary_nebula 12. https://www.youtube.com/watch?v=KXNSYo8ZdoU 13. https://apod.nasa.gov/apod/ap171231.html 14. http://mathworld.wolfram.com/Helix.html 15. https://imagine.gsfc.nasa.gov/science/objects/dwarfs2.html 16. https://science.nasa.gov/ems/10_ultravioletwaves 17. https://www.youtube.com/watch?v=YvN8zFhWn04 18. http://www.messier.seds.org/xtra/ngc/n7293.html 19. https://apod.nasa.gov/apod/ap041229.html 20. https://chandra.harvard.edu/photo/cosmic_distance.html 21. https://starchild.gsfc.nasa.gov/docs/StarChild/questions/question9.html 22. https://en.wikipedia.org/wiki/Aquarius_(constellation) 23. http://www.cfht.hawaii.edu/HawaiianStarlight/AIOM/English/CFHT-Coelum-AIOM-Mar2017.html 24. https://www.cfht.hawaii.edu/en/about/ 25. https://en.wikipedia.org/wiki/Hawaii#/media/File:Hawaii_in_United_States_(zoom)_(US50)_(-grid).svg 26. https://www.cia.gov/library/publications/the-world-factbook/geos/us.html 27. https://www.youtube.com/watch?v=UwAKNMC2PeM 28. https://apod.nasa.gov/apod/ap080413.html 29. http://hubblesite.org/newscenter/archive/2003/11/fastfacts 30. https://ui.adsabs.harvard.edu/abs/2002ApJ...573L..55H/abstract 31. https://apod.nasa.gov/apod/ap201123.html 32. https://apod.nasa.gov/apod/archivepix.html 33. https://apod.nasa.gov/apod/lib/apsubmit2015.html 34. https://apod.nasa.gov/apod/lib/aptree.html 35. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 36. https://apod.nasa.gov/apod/calendar/allyears.html 37. https://apod.nasa.gov/apod.rss 38. https://apod.nasa.gov/apod/lib/edlinks.html 39. https://apod.nasa.gov/apod/lib/about_apod.html 40. http://asterisk.apod.com/discuss_apod.php?date=201124 41. https://apod.nasa.gov/apod/ap201125.html 42. http://www.phy.mtu.edu/faculty/Nemiroff.html 43. http://www.phy.mtu.edu/ 44. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 45. http://www.astro.umd.edu/ 46. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 47. https://www.nasa.gov/about/highlights/HP_Privacy.html 48. https://astrophysics.gsfc.nasa.gov/ 49. https://www.nasa.gov/ 50. https://www.nasa.gov/centers/goddard/ 51. http://www.mtu.edu/