¿ 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. 2021 February 21 [2]See Explanation. Clicking on the picture will download the highest resolution version available. NGC 2244: A Star Cluster in the Rosette Nebula Image Credit & [3]Copyright: [4]Don Goldman Explanation: In the heart of the [5]Rosette Nebula lies a bright [6]open cluster of stars that lights up the nebula. The stars of [7]NGC 2244 formed from the surrounding gas only a few million years ago. The [8]featured image taken in January using multiple exposures and very specific colors of [9]Sulfur (shaded red), [10]Hydrogen (green), and [11]Oxygen (blue), captures the central region in tremendous detail. A hot [12]wind of particles streams away from the cluster [13]stars and contributes to an already [14]complex menagerie of gas and [15]dust filaments while slowly evacuating the cluster center. The [16]Rosette Nebula's center measures about 50 [17]light-years across, lies about 5,200 light-years away, and is visible with binoculars towards the constellation of the Unicorn ([18]Monoceros). Tomorrow's picture: report from mars __________________________________________________________________ [19]< | [20]Archive | [21]Submissions | [22]Index | [23]Search | [24]Calendar | [25]RSS | [26]Education | [27]About APOD | [28]Discuss | [29]> __________________________________________________________________ Authors & editors: [30]Robert Nemiroff ([31]MTU) & [32]Jerry Bonnell ([33]UMCP) NASA Official: Phillip Newman [34]Specific rights apply. [35]NASA Web Privacy Policy and Important Notices A service of: [36]ASD at [37]NASA / [38]GSFC & [39]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2102/rosette_goldman_2500.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://www.astrodonimaging.com/ 5. https://apod.nasa.gov/apod/ap120214.html 6. https://en.wikipedia.org/wiki/Open_cluster 7. https://www.youtube.com/watch?v=rQ4n2HjppWo 8. https://astrodonimaging.com/gallery/in-the-heart-of-the-rosette/ 9. https://periodic.lanl.gov/16.shtml 10. https://periodic.lanl.gov/1.shtml 11. https://periodic.lanl.gov/8.shtml 12. https://pwg.gsfc.nasa.gov/Education/wsolwind.html 13. https://science.nasa.gov/astrophysics/focus-areas/how-do-stars-form-and-evolve 14. https://assets3.thrillist.com/v1/image/2499821/414x310/scale;jpeg_quality=65.jpg 15. http://nedwww.ipac.caltech.edu/level5/Mathis/Mathis1.html 16. https://apod.nasa.gov/apod/ap210214.html 17. https://chandra.harvard.edu/photo/cosmic_distance.html 18. https://en.wikipedia.org/wiki/Monoceros 19. https://apod.nasa.gov/apod/ap210220.html 20. https://apod.nasa.gov/apod/archivepix.html 21. https://apod.nasa.gov/apod/lib/apsubmit2015.html 22. https://apod.nasa.gov/apod/lib/aptree.html 23. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 24. https://apod.nasa.gov/apod/calendar/allyears.html 25. https://apod.nasa.gov/apod.rss 26. https://apod.nasa.gov/apod/lib/edlinks.html 27. https://apod.nasa.gov/apod/lib/about_apod.html 28. http://asterisk.apod.com/discuss_apod.php?date=210221 29. https://apod.nasa.gov/apod/ap210222.html 30. http://www.phy.mtu.edu/faculty/Nemiroff.html 31. http://www.phy.mtu.edu/ 32. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 33. http://www.astro.umd.edu/ 34. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 35. https://www.nasa.gov/about/highlights/HP_Privacy.html 36. https://astrophysics.gsfc.nasa.gov/ 37. https://www.nasa.gov/ 38. https://www.nasa.gov/centers/goddard/ 39. http://www.mtu.edu/