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 August 23 [2]See Explanation. Clicking on the picture will download the highest resolution version available. Supernova Remnant CTA 1 Image Credit & [3]Copyright: [4]Thomas Lelu Explanation: There is a [5]quiet pulsar at the heart of CTA 1. The supernova remnant was [6]discovered as a source of emission [7]at radio wavelengths by astronomers in 1960 and since identified as the result of the death explosion of a massive star. But no radio pulses were detected from the expected pulsar, the [8]rotating neutron star remnant of the massive star's collapsed core. Seen about 10,000 years after the initial supernova explosion, the interstellar debris cloud is faint at optical wavelengths. CTA 1's visible wavelength emission from still expanding shock fronts is revealed in [9]this deep telescopic image, a frame that spans about 2 degrees across a starfield in the northern constellation of Cepheus. While no pulsar has since been found at radio wavelengths, in 2008 the [10]Fermi Gamma-ray Space Telescope detected pulsed emission from CTA 1, identifying the supernova remnant's rotating neutron star. The source has been recognized as the first in a growing class of pulsars that are quiet at radio wavelengths but [11]pulse in high-energy gamma-rays. Tomorrow's picture: light-weekend __________________________________________________________________ [12]< | [13]Archive | [14]Submissions | [15]Index | [16]Search | [17]Calendar | [18]RSS | [19]Education | [20]About APOD | [21]Discuss | [22]> __________________________________________________________________ Authors & editors: [23]Robert Nemiroff ([24]MTU) & [25]Jerry Bonnell ([26]UMCP) NASA Official: Amber Straughn [27]Specific rights apply. [28]NASA Web Privacy, [29]Accessibility Notices A service of: [30]ASD at [31]NASA / [32]GSFC, [33]NASA Science Activation & [34]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2408/CTA1_15_75_Lelu2048.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. http://www.astrophotographie-lorraine.com/ 5. https://www.science.org/doi/10.1126/sciadv.aao7228 6. https://www.deepskycorner.ch/obj/cta1.en.php 7. https://science.nasa.gov/ems/05_radiowaves/ 8. https://apod.nasa.gov/apod/ap240723.html 9. https://www.astrobin.com/3vfxec/0/ 10. https://science.nasa.gov/mission/fermi 11. https://www.nasa.gov/centers-and-facilities/goddard/nasas-fermi-telescope-discovers-first-gamma-ray-only-pulsar/ 12. https://apod.nasa.gov/apod/ap240822.html 13. https://apod.nasa.gov/apod/archivepix.html 14. https://apod.nasa.gov/apod/lib/apsubmit2015.html 15. https://apod.nasa.gov/apod/lib/aptree.html 16. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 17. https://apod.nasa.gov/apod/calendar/allyears.html 18. https://apod.nasa.gov/apod.rss 19. https://apod.nasa.gov/apod/lib/edlinks.html 20. https://apod.nasa.gov/apod/lib/about_apod.html 21. http://asterisk.apod.com/discuss_apod.php?date=240823 22. https://apod.nasa.gov/apod/ap240824.html 23. http://www.phy.mtu.edu/faculty/Nemiroff.html 24. http://www.phy.mtu.edu/ 25. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 26. http://www.astro.umd.edu/ 27. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 28. https://www.nasa.gov/about/highlights/HP_Privacy.html 29. https://www.nasa.gov/general/accessibility/ 30. https://astrophysics.gsfc.nasa.gov/ 31. https://www.nasa.gov/ 32. https://www.nasa.gov/centers/goddard/ 33. https://science.nasa.gov/learners 34. http://www.mtu.edu/