﻿ 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. 2022 January 24 [2]The featured image shows the star Rigel and the nearby Witch Head Nebula, which is a reflection nebula illuminated by Rigel. Please see the explanation for more detailed information. Rigel and the Witch Head Nebula Image Credit & Copyright: [3]José Mtanous Explanation: By starlight this eerie visage shines in the dark, a crooked profile evoking its popular name, the [4]Witch Head Nebula. In fact, this entrancing [5]telescopic portrait gives the impression that the witch has fixed her gaze on Orion's bright supergiant [6]star Rigel. More formally known as [7]IC 2118, the Witch Head Nebula spans about 50 [8]light-years and is composed of interstellar dust grains reflecting [9]Rigel's starlight. The blue color of the Witch Head Nebula and of the dust surrounding [10]Rigel is caused not only by [11]Rigel's intense blue starlight but because the [12]dust grains scatter blue light more efficiently than red. The same [13]physical process causes [14]Earth's daytime sky to appear blue, although the scatterers in [15]Earth's atmosphere are molecules of [16]nitrogen and [17]oxygen. Rigel, the [18]Witch Head Nebula, and gas and dust that surrounds them lie about 800 [19]light-years away. Tomorrow's picture: open space __________________________________________________________________ [20]< | [21]Archive | [22]Submissions | [23]Index | [24]Search | [25]Calendar | [26]RSS | [27]Education | [28]About APOD | [29]Discuss | [30]> __________________________________________________________________ Authors & editors: [31]Robert Nemiroff ([32]MTU) & [33]Jerry Bonnell ([34]UMCP) NASA Official: Phillip Newman [35]Specific rights apply. [36]NASA Web Privacy Policy and Important Notices A service of: [37]ASD at [38]NASA / [39]GSFC & [40]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2201/RigelWitchHead_Mtanous_2834.jpg 3. https://mtanous.wordpress.com/ 4. https://apod.nasa.gov/apod/ap061211.html 5. https://mtanous.files.wordpress.com/2022/01/bruja1v1_enhancedarks.jpg 6. https://en.wikipedia.org/wiki/Rigel 7. https://en.wikipedia.org/wiki/IC_2118 8. https://exoplanets.nasa.gov/faq/26/what-is-a-light-year/ 9. https://ui.adsabs.harvard.edu/abs/1997MNRAS.290..521I/abstract 10. http://www.youtube.com/watch?v=c8CgDGhYKe8 11. http://stars.astro.illinois.edu/sow/rigel.html 12. https://astronomy.swin.edu.au/cosmos/d/Dust+Grain 13. http://hyperphysics.phy-astr.gsu.edu/hbase/atmos/blusky.html 14. https://spaceplace.nasa.gov/blue-sky/en/ 15. https://www.nasa.gov/mission_pages/sunearth/science/atmosphere-layers2.html 16. https://youtu.be/DqI9caqBHkg 17. https://www.space.com/webb-space-telescope-exoplanet-oxygen-detection.html 18. https://apod.nasa.gov/apod/ap151030.html 19. http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html 20. https://apod.nasa.gov/apod/ap220123.html 21. https://apod.nasa.gov/apod/archivepix.html 22. https://apod.nasa.gov/apod/lib/apsubmit2015.html 23. https://apod.nasa.gov/apod/lib/aptree.html 24. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 25. https://apod.nasa.gov/apod/calendar/allyears.html 26. https://apod.nasa.gov/apod.rss 27. https://apod.nasa.gov/apod/lib/edlinks.html 28. https://apod.nasa.gov/apod/lib/about_apod.html 29. http://asterisk.apod.com/discuss_apod.php?date=220124 30. https://apod.nasa.gov/apod/ap220125.html 31. http://www.phy.mtu.edu/faculty/Nemiroff.html 32. http://www.phy.mtu.edu/ 33. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 34. http://www.astro.umd.edu/ 35. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 36. https://www.nasa.gov/about/highlights/HP_Privacy.html 37. https://astrophysics.gsfc.nasa.gov/ 38. https://www.nasa.gov/ 39. https://www.nasa.gov/centers/goddard/ 40. http://www.mtu.edu/