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 November 3 [2]The featured image shows steam rising from several separated vents at Hverir, a geothermally active field in Iceland. Green aurora rage in the background. Please see the explanation for more detailed information. M33: The Triangulum Galaxy Image Credit & [3]Copyright: Processing - [4]Robert Gendler Data - [5]Hubble Legacy Archive, [6]KPNO, [7]NOIRLab, [8]NSF, [9]Aura, [10]Amateur Sources Explanation: The small, northern constellation [11]Triangulum harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the [12]Triangulum Galaxy. M33 is over 50,000 light-years in diameter, third largest in the [13]Local Group of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. [14]About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy and [15]astronomers in these two galaxies would likely have spectacular views of each other's grand spiral star systems. As for the view from the Milky Way, [16]this sharp image combines data from telescopes on and around planet Earth to show off M33's blue star clusters and pinkish [17]star forming regions along the galaxy's loosely wound spiral arms. In fact, the [18]cavernous NGC 604 is the brightest star forming region, seen here at about the 1 o'clock position from the galaxy center. Like M31, M33's population of well-measured variable stars have helped make this nearby spiral a cosmic yardstick for [19]establishing the distance [20]scale of the Universe. Tomorrow's picture: pixels in space __________________________________________________________________ [21]< | [22]Archive | [23]Submissions | [24]Index | [25]Search | [26]Calendar | [27]RSS | [28]Education | [29]About APOD | [30]Discuss | [31]> __________________________________________________________________ Authors & editors: [32]Robert Nemiroff ([33]MTU) & [34]Jerry Bonnell ([35]UMCP) NASA Official: Phillip Newman [36]Specific rights apply. [37]NASA Web Privacy Policy and Important Notices A service of: [38]ASD at [39]NASA / [40]GSFC, [41]NASA Science Activation & [42]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2211/M33-NOIR-HST-LL.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. http://www.robgendlerastropics.com/ 5. https://hla.stsci.edu/ 6. https://noirlab.edu/public/programs/kitt-peak-national-observatory/nicholas-mayall-4m-telescope/ 7. https://noirlab.edu/public/ 8. https://www.nsf.gov/ 9. https://www.aura-astronomy.org/ 10. http://www.robgendlerastropics.com/M33-NOIR-HST.html 11. http://www.hawastsoc.org/deepsky/tri/index.html 12. http://messier.seds.org/m/m033.html 13. http://atlasoftheuniverse.com/localgr.html 14. https://apod.nasa.gov/apod/ap211106.html 15. http://arxiv.org/abs/astro-ph?papernum=0506609 16. http://www.robgendlerastropics.com/M33-NOIR-HST.html 17. https://apod.nasa.gov/apod/ap091017.html 18. https://esahubble.org/images/opo9627c/ 19. http://adsabs.harvard.edu/cgi-bin/bib_query?1926ApJ....63..236H 20. http://antwrp.gsfc.nasa.gov/diamond_jubilee/debate96.html 21. https://apod.nasa.gov/apod/ap221102.html 22. https://apod.nasa.gov/apod/archivepix.html 23. https://apod.nasa.gov/apod/lib/apsubmit2015.html 24. https://apod.nasa.gov/apod/lib/aptree.html 25. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 26. https://apod.nasa.gov/apod/calendar/allyears.html 27. https://apod.nasa.gov/apod.rss 28. https://apod.nasa.gov/apod/lib/edlinks.html 29. https://apod.nasa.gov/apod/lib/about_apod.html 30. http://asterisk.apod.com/discuss_apod.php?date=221103 31. https://apod.nasa.gov/apod/ap221104.html 32. http://www.phy.mtu.edu/faculty/Nemiroff.html 33. http://www.phy.mtu.edu/ 34. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 35. http://www.astro.umd.edu/ 36. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 37. https://www.nasa.gov/about/highlights/HP_Privacy.html 38. https://astrophysics.gsfc.nasa.gov/ 39. https://www.nasa.gov/ 40. https://www.nasa.gov/centers/goddard/ 41. https://science.nasa.gov/learners 42. http://www.mtu.edu/