﻿ 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 August 22 [2]A diffuse nebula is seen against a dark starfield. The center of the nebula is blue and it is surrounded by a red glow. Please see the explanation for more detailed information. The Pistachio Nebula Credit & Copyright: [3]Bray Falls & [4]Chester Hall-Fernandez Explanation: This nebula had never been noted before. Newly discovered nebulas are usually angularly small and found by professionals using large telescopes. In contrast, the [5]Pistachio Nebula was [6]discovered by dedicated amateurs and, although faint, is nearly the size of the full Moon. In modern times, amateurs with even small telescopes can create long exposures over sky areas much larger than most professional telescopes can see. They can therefore discover both [7]previously unknown areas of [8]extended emission around known objects, as well as [9]entirely unknown objects, like nebulas. The pictured Pistachio Nebula is shown in [10]oxygen emission (blue) and [11]hydrogen emission (red). The nature of the hot central star is currently unknown, and the nebula might be labeled a [12]planetary nebula if it turns out to be a [13]white dwarf star. The [14]featured image is a composite of over 70 hours of exposure taken in early June under the dark skies of [15]Namibia. Tomorrow's picture: comet rain __________________________________________________________________ [16]< | [17]Archive | [18]Submissions | [19]Index | [20]Search | [21]Calendar | [22]RSS | [23]Education | [24]About APOD | [25]Discuss | [26]> __________________________________________________________________ Authors & editors: [27]Robert Nemiroff ([28]MTU) & [29]Jerry Bonnell ([30]UMCP) NASA Official: Phillip Newman [31]Specific rights apply. [32]NASA Web Privacy Policy and Important Notices A service of: [33]ASD at [34]NASA / [35]GSFC, [36]NASA Science Activation & [37]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2308/Pistachio_Falls_2952.jpg 3. https://www.instagram.com/astrofalls/ 4. https://www.instagram.com/astro_che/ 5. https://www.astrobin.com/idmd45/B/ 6. https://youtu.be/qhH_jQciyhE 7. https://cdn.petcarerx.com/blog/wp-content-uploads-2015-07-surprise-dog.jpg 8. https://apod.nasa.gov/apod/ap230117.html 9. https://apod.nasa.gov/apod/ap160725.html 10. https://climate.nasa.gov/news/2491/10-interesting-things-about-air/ 11. https://periodic.lanl.gov/1.shtml 12. https://en.wikipedia.org/wiki/Planetary_nebula 13. https://www.nasa.gov/multimedia/imagegallery/image_feature_734.html 14. https://www.astrobin.com/idmd45/ 15. https://en.wikipedia.org/wiki/Namibia 16. https://apod.nasa.gov/apod/ap230821.html 17. https://apod.nasa.gov/apod/archivepix.html 18. https://apod.nasa.gov/apod/lib/apsubmit2015.html 19. https://apod.nasa.gov/apod/lib/aptree.html 20. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 21. https://apod.nasa.gov/apod/calendar/allyears.html 22. https://apod.nasa.gov/apod.rss 23. https://apod.nasa.gov/apod/lib/edlinks.html 24. https://apod.nasa.gov/apod/lib/about_apod.html 25. https://asterisk.apod.com/discuss_apod.php?date=230822 26. https://apod.nasa.gov/apod/ap230823.html 27. http://www.phy.mtu.edu/faculty/Nemiroff.html 28. http://www.phy.mtu.edu/ 29. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 30. http://www.astro.umd.edu/ 31. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 32. https://www.nasa.gov/about/highlights/HP_Privacy.html 33. https://astrophysics.gsfc.nasa.gov/ 34. https://www.nasa.gov/ 35. https://www.nasa.gov/centers/goddard/ 36. https://science.nasa.gov/learners 37. http://www.mtu.edu/