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 October 5 [2]See Explanation. Clicking on the picture will download the highest resolution version available. M27: Not a Comet Image Credit & [3]Copyright: [4]Francesco Sferlazza, Franco Sgueglia Explanation: While hunting for comets in the skies above 18th century France, [5]astronomer Charles Messier diligently kept a list of the things encountered during his telescopic expeditions that were definitely not comets. This is number 27 on his [6]now famous not-a-comet list. In fact, 21st century astronomers would identify it as a [7]planetary nebula, but it's not a planet either, even though it may [8]appear round and planet-like in a small telescope. Messier 27 (M27) is an excellent example of a gaseous emission nebula created as a [9]sun-like star runs out of nuclear fuel in its core. The nebula forms as the star's outer layers are expelled into space, with a visible glow generated by atoms excited by the dying star's intense but invisible [10]ultraviolet light. Known by the popular name of the [11]Dumbbell Nebula, the beautifully symmetric interstellar gas cloud is over 2.5 light-years across and about 1,200 light-years away in the [12]constellation Vulpecula. This impressive color image highlights details within the well-studied central region and fainter, seldom imaged features in the nebula's [13]outer halo. Tomorrow's picture: a comet's tale __________________________________________________________________ [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: Phillip Newman [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/2410/m27_RGB_CC_FLAT_MEW.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. http://www.astrobrallo.com/ 5. https://science.nasa.gov/people/explore-the-night-sky-hubbleatms-messier-catalog-bio/ 6. http://messier.seds.org/xtra/history/m-cat.html 7. http://messier.seds.org/planetar.html 8. https://apod.nasa.gov/apod/ap030614.html 9. https://apod.nasa.gov/apod/ap100221.html 10. http://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html 11. https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-27/ 12. http://hawastsoc.org/deepsky/vul/index.html 13. https://apod.nasa.gov/apod/ap100509.html 14. https://apod.nasa.gov/apod/ap241004.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=241005 24. https://apod.nasa.gov/apod/ap241006.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/