﻿ 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 April 30 [2]A faint nebula runs vertically in the image. In the center is a red envelope surrounding diffuse blue emission. In the center is a bright multicolored nebula that is nearly circular. Please see the explanation for more detailed information. GK Per: Nova and Planetary Nebula Image Credit & Copyright: [3]Deep Sky Collective Explanation: The star system GK Per is known to be associated with only two of the three nebulas [4]pictured. At 1500 [5]light years distant, Nova Persei 1901 ([6]GK Persei) was the second closest [7]nova yet recorded. At the very center is a [8]white dwarf star, the surviving core of a former Sun-like star. It is surrounded by the circular [9]Firework nebula, gas that was ejected by a [10]thermonuclear explosion on the white dwarf's surface -- a nova -- as [11]recorded in 1901. The red glowing gas surrounding the Firework nebula is the atmosphere that used to surround the central star. This gas was expelled before the [12]nova and appears as a diffuse [13]planetary nebula. The [14]faint gray gas running across is [15]interstellar cirrus that seems to be [16]just passing through coincidently. In 1901, GK Per's nova [17]became brighter than [18]Betelgeuse. Similarly, star system [19]T CrB is expected to erupt in a nova later this year, but we don't know exactly when nor [20]how bright it will become. Tomorrow's picture: sky fish __________________________________________________________________ [21]< | [22]Archive | [23]Submissions | [24]Index | [25]Search | [26]Calendar | [27]RSS | [28]Education | [29]About APOD | [30]Discuss | [31]> __________________________________________________________________ Authors & editors: [32]Robert Nemiroff ([33]MTU) & [34]Jerry Bonnell ([35]UMCP) NASA Official: Amber Straughn [36]Specific rights apply. [37]NASA Web Privacy, [38]Accessibility, [39]Notices; A service of: [40]ASD at [41]NASA / [42]GSFC, [43]NASA Science Activation & [44]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2404/GKPerWide_DSC_4329.jpg 3. https://deepskycollective.com/ 4. https://www.astrobin.com/ocm8rv/ 5. https://spaceplace.nasa.gov/light-year/ 6. https://en.wikipedia.org/wiki/GK_Persei 7. https://en.wikipedia.org/wiki/Nova 8. https://science.nasa.gov/universe/stars/types/#white-dwarfs 9. https://apod.nasa.gov/apod/ap980704.html 10. https://youtu.be/11e8XyUBqRQ 11. https://www.aavso.org/vsots_gkper 12. https://youtu.be/zYmd8EETy74 13. https://apod.nasa.gov/apod/ap230416.html 14. https://deepskycollective.com/gkpersei/lrgbhoo 15. https://www.cosmotography.com/images/galactic_cirrus.html 16. https://arxiv.org/abs/2201.10332 17. https://media.zenfs.com/en_US/News/BGR_News/scared-surprised-cat-face.jpg 18. https://apod.nasa.gov/apod/ap200511.html 19. https://blogs.nasa.gov/Watch_the_Skies/2024/02/27/view-nova-explosion-new-star-in-northern-crown/ 20. https://en.wikipedia.org/wiki/T_Coronae_Borealis 21. https://apod.nasa.gov/apod/ap240429.html 22. https://apod.nasa.gov/apod/archivepix.html 23. https://apod.nasa.gov/apod/lib/apsubmit2015.html 24. https://apod.nasa.gov/apod/lib/aptree.html 25. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 26. https://apod.nasa.gov/apod/calendar/allyears.html 27. https://apod.com/feed.rss 28. https://apod.nasa.gov/apod/lib/edlinks.html 29. https://apod.nasa.gov/apod/lib/about_apod.html 30. https://asterisk.apod.com/discuss_apod.php?date=240430 31. https://apod.nasa.gov/apod/ap240501.html 32. http://www.phy.mtu.edu/faculty/Nemiroff.html 33. http://www.phy.mtu.edu/ 34. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 35. http://www.astro.umd.edu/ 36. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 37. https://www.nasa.gov/about/highlights/HP_Privacy.html 38. https://www.nasa.gov/general/accessibility/ 39. https://www.nasa.gov/privacy/ 40. https://astrophysics.gsfc.nasa.gov/ 41. https://www.nasa.gov/ 42. https://www.nasa.gov/centers/goddard/ 43. https://science.nasa.gov/learners 44. http://www.mtu.edu/