﻿ 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. 2023 April 24 [2]A nearly spherical but stringy nebula is shown against a starry background. The nebula is colored blue and red. Please see the explanation for more detailed information. The Medulla Nebula Supernova Remnant Image Credit & Copyright: [3]Kimberly Sibbald Explanation: What powers this unusual nebula? CTB-1 is the expanding gas shell that was left when a massive star toward the constellation of [4]Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements near its core that could create [5]stabilizing pressure with [6]nuclear fusion. The resulting [7]supernova remnant, nicknamed the Medulla Nebula for its [8]brain-like shape, still glows in [9]visible light by the heat generated by its collision with confining [10]interstellar gas. Why [11]the nebula also glows in [12]X-ray light, though, [13]remains a mystery. One hypothesis holds that an energetic [14]pulsar was co-created that powers the nebula with a fast outwardly moving wind. Following this lead, a pulsar has [15]recently been found in [16]radio waves that appears to have [17]been expelled by the [18]supernova explosion at over 1000 kilometers per second. Although the [19]Medulla Nebula appears as large as a [20]full moon, it is so faint that it took many hours of exposure with a telescope in [21]Seven Persons, [22]Alberta, [23]Canada to create the [24]featured image. Tomorrow's picture: lunar triomuphe __________________________________________________________________ [25]< | [26]Archive | [27]Submissions | [28]Index | [29]Search | [30]Calendar | [31]RSS | [32]Education | [33]About APOD | [34]Discuss | [35]> __________________________________________________________________ Authors & editors: [36]Robert Nemiroff ([37]MTU) & [38]Jerry Bonnell ([39]UMCP) NASA Official: Phillip Newman [40]Specific rights apply. [41]NASA Web Privacy Policy and Important Notices A service of: [42]ASD at [43]NASA / [44]GSFC, [45]NASA Science Activation & [46]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2304/CTB1_Sibbald_6209.jpg 3. https://spacepaparazzi.com/aboutkms/ 4. https://en.wikipedia.org/wiki/Cassiopeia_(constellation) 5. http://large.stanford.edu/courses/2011/ph241/olson1/ 6. https://en.wikipedia.org/wiki/Nuclear_fusion 7. https://imagine.gsfc.nasa.gov/science/objects/supernova_remnants.html 8. https://en.wikipedia.org/wiki/Medulla_oblongata 9. https://science.nasa.gov/ems/09_visiblelight 10. https://apod.nasa.gov/apod/ap130924.html 11. https://ui.adsabs.harvard.edu/abs/2018PASJ...70..110K/abstract 12. https://science.nasa.gov/ems/11_xrays 13. https://www.barkbusters.co.uk/images/articles/7a4120f095480e9f2a2ad2a165d90313.jpg 14. https://en.wikipedia.org/wiki/Pulsar 15. https://ui.adsabs.harvard.edu/abs/2019sros.confE.158K/abstract 16. https://science.nasa.gov/ems/05_radiowaves 17. https://apod.nasa.gov/apod/ap221002.html 18. https://youtu.be/aysiMbgml5g 19. https://www.gxccd.com/art?id=543&cat=1&lang=409 20. https://apod.nasa.gov/apod/ap220612.html 21. https://en.wikipedia.org/wiki/Seven_Persons 22. https://en.wikipedia.org/wiki/Alberta 23. https://en.wikipedia.org/wiki/Canada 24. https://www.astrobin.com/t54gkx/B/ 25. https://apod.nasa.gov/apod/ap230423.html 26. https://apod.nasa.gov/apod/archivepix.html 27. https://apod.nasa.gov/apod/lib/apsubmit2015.html 28. https://apod.nasa.gov/apod/lib/aptree.html 29. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 30. https://apod.nasa.gov/apod/calendar/allyears.html 31. https://apod.nasa.gov/apod.rss 32. https://apod.nasa.gov/apod/lib/edlinks.html 33. https://apod.nasa.gov/apod/lib/about_apod.html 34. https://asterisk.apod.com/discuss_apod.php?date=230424 35. https://apod.nasa.gov/apod/ap230425.html 36. http://www.phy.mtu.edu/faculty/Nemiroff.html 37. http://www.phy.mtu.edu/ 38. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 39. http://www.astro.umd.edu/ 40. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 41. https://www.nasa.gov/about/highlights/HP_Privacy.html 42. https://astrophysics.gsfc.nasa.gov/ 43. https://www.nasa.gov/ 44. https://www.nasa.gov/centers/goddard/ 45. https://science.nasa.gov/learners 46. http://www.mtu.edu/