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. 2019 October 25 [2]See Explanation. Clicking on the picture will download the highest resolution version available. The Ghosts of Cassiopeia Image Credit & [3]Copyright: Tommaso Stella Explanation: These bright rims and flowing shapes look ghostly on a cosmic scale. A telescopic view toward the constellation [4]Cassiopeia, the colorful skyscape features swept-back, comet-shaped clouds IC 59 (left) and IC 63. About 600 light-years distant, [5]the clouds aren't actually ghosts. They are slowly disappearing though, under the influence of [6]energetic radiation from hot,luminous star gamma Cas. [7]Gamma Cas is physically located only 3 to 4 light-years from the nebulae, the bright star just above and left in the frame. Slightly closer to gamma Cas, IC 63 is dominated by [8]red H-alpha light emitted as hydrogen atoms ionized by the star's ultraviolet radiation recombine with electrons. Farther from the star, IC 59 shows proportionally less H-alpha emission but more of the characteristic blue tint of dust [9]reflected star light. The field of view spans over 1 degree or 10 light-years at the estimated distance of [10]gamma Cas and friends. Tomorrow's picture: only the smile __________________________________________________________________ [11]< | [12]Archive | [13]Submissions | [14]Index | [15]Search | [16]Calendar | [17]RSS | [18]Education | [19]About APOD | [20]Discuss | [21]> __________________________________________________________________ Authors & editors: [22]Robert Nemiroff ([23]MTU) & [24]Jerry Bonnell ([25]UMCP) NASA Official: Phillip Newman [26]Specific rights apply. [27]NASA Web Privacy Policy and Important Notices A service of: [28]ASD at [29]NASA / [30]GSFC & [31]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/1910/IC59IC63TheGhostsOfCassiopeiaTommasoStella2019.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://apod.nasa.gov/apod/ap160318.html 5. http://iopscience.iop.org/1538-3881/129/2/954 6. https://arxiv.org/abs/1809.01419 7. https://www.aavso.org/vsots_gammacas 8. https://apod.nasa.gov/apod/ap111013.html 9. https://apod.nasa.gov/apod/ap091126.html 10. https://arxiv.org/abs/1705.04313 11. https://apod.nasa.gov/apod/ap191024.html 12. https://apod.nasa.gov/apod/archivepix.html 13. https://apod.nasa.gov/apod/lib/apsubmit2015.html 14. https://apod.nasa.gov/apod/lib/aptree.html 15. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 16. https://apod.nasa.gov/apod/calendar/allyears.html 17. https://apod.nasa.gov/apod.rss 18. https://apod.nasa.gov/apod/lib/edlinks.html 19. https://apod.nasa.gov/apod/lib/about_apod.html 20. http://asterisk.apod.com/discuss_apod.php?date=191025 21. https://apod.nasa.gov/apod/ap191026.html 22. http://www.phy.mtu.edu/faculty/Nemiroff.html 23. http://www.phy.mtu.edu/ 24. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 25. http://www.astro.umd.edu/ 26. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 27. https://www.nasa.gov/about/highlights/HP_Privacy.html 28. https://astrophysics.gsfc.nasa.gov/ 29. https://www.nasa.gov/ 30. https://www.nasa.gov/centers/goddard/ 31. http://www.mtu.edu/