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. 2026 July 16 [2]A bright spiral galaxy shows stars and colorful clous of gas in red, green and blue colors. The background is a dark field of stars. NGC 300: A Cosmic Gemstone with Stars and Gas Clouds Image Credit & Copyright: [3]Team Ciel Austral Text: [4]Cecilia Chirenti ([5]NASA [6]GSFC, [7]UMCP, [8]CRESST II) Explanation: [9]This sparkling, colorful gemstone is a spiral galaxy, [10]NGC 300. It is one of the closest [11]spiral galaxies to Earth, only about 6 million light-years away. But does it really [12]look like this? [13]Here is a more standard portrait of it. This unusual image combines the light from the [14]stars and [15]dust within the galaxy with the light from ionized clouds of [16]interstellar gas shown in red (Sulphur), green (Hydrogen) and blue (Oxygen). Combining red and green light in [17]different proportions makes yellow or orange light, most visible in the image. Light from other ionized gases is also [18]at work in neon signs, fluorescent tubes and street lights. These [19]massive clouds of ionized gas are typically created by young, massive stars that produce high-energy [20]ultraviolet radiation capable of ionizing the gas. Massive stars are [21]short-lived, compared with lighter stars like our sun, and explode as [22]supernovas at the end of their lives. Some of the colorful clouds in the image could be [23]hiding [24]supernova remnants. Tomorrow's picture: What's next? __________________________________________________________________ [25]< | [26]Archive | [27]Submissions | [28]Index | [29]Search | [30]Calendar | [31]RSS | [32]Education | [33]About APOD | [34]Discuss | [35]> __________________________________________________________________ Authors & editors: [36]Robert Nemiroff ([37]MTU) & [38]Jerry Bonnell ([39]UMCP) NASA Official: Amber Straughn [40]Specific rights apply. [41]NASA Web Privacy, [42]Accessibility, [43]Notices; A service of: [44]ASD at [45]NASA / [46]GSFC, [47]NASA Science Activation & [48]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2607/ngc300.jpg 3. https://www.cielaustral.com/contact2.htm 4. https://science.gsfc.nasa.gov/sci/bio/cecilia.chirenti 5. https://www.nasa.gov/ 6. https://www.nasa.gov/goddard/ 7. https://www.astro.umd.edu/people/cecilia-chirenti 8. https://cresst2.umd.edu/ 9. https://www.cielaustral.com/galerie/photo197.htm 10. https://en.wikipedia.org/wiki/NGC_300 11. https://science.nasa.gov/universe/galaxies/types/#spiral-galaxies 12. https://images.unsplash.com/photo-1606509779095-de8fd5187049 13. https://apod.nasa.gov/apod/ap241202.html 14. https://science.nasa.gov/universe/stars/ 15. https://en.wikipedia.org/wiki/Cosmic_dust 16. https://cesar.esa.int/upload/201801/ism_booklet.pdf 17. https://isle.hanover.edu/Ch06Color/Ch06ColorMixer.html 18. https://en.wikipedia.org/wiki/Gas-discharge_lamp 19. https://astronomy.swin.edu.au/cosmos/*/HII+Region 20. https://science.nasa.gov/ems/10_ultravioletwaves/ 21. https://www.starinabox.net/ 22. https://spaceplace.nasa.gov/supernova/en/ 23. https://www.aanda.org/articles/aa/abs/2004/38/aa1058/aa1058.html 24. https://chandra.harvard.edu/xray_sources/supernovas.html 25. https://apod.nasa.gov/apod/ap260715.html 26. https://apod.nasa.gov/apod/archivepix.html 27. https://apod.nasa.gov/apod/lib/apsubmit2015.html 28. https://apod.nasa.gov/apod/lib/aptree.html 29. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 30. https://apod.nasa.gov/apod/calendar/allyears.html 31. https://apod.com/feed.rss 32. https://apod.nasa.gov/apod/lib/edlinks.html 33. https://apod.nasa.gov/apod/lib/about_apod.html 34. https://asterisk.apod.com/discuss_apod.php?date=260716 35. https://apod.nasa.gov/apod/ap260717.html 36. https://www.mtu.edu/physics/department/faculty/nemiroff/ 37. https://www.mtu.edu/physics/ 38. https://inspirehep.net/authors/1073087 39. http://www.astro.umd.edu/ 40. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 41. https://www.nasa.gov/about/highlights/HP_Privacy.html 42. https://www.nasa.gov/general/accessibility/ 43. https://www.nasa.gov/privacy/ 44. https://science.gsfc.nasa.gov/astrophysics/ 45. https://www.nasa.gov/ 46. https://www.nasa.gov/centers/goddard/ 47. https://science.nasa.gov/learn/about-science-activation/ 48. http://www.mtu.edu/