The small constellation Triangulum [
http://www.hawastso…] in the northern sky harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy [
http://www.seds.org…]. M33's diameter spans over 50,000 light-years, making it third largest in the Local Group [
http://www.anzwers.…] of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 lies very close to the Andromeda Galaxy [
http://antwrp.gsfc.…] and observers [
http://www.astr.ua.…] in these two galaxies would likely have spectacular views of each other's grand spiral star systems. As for the view from planet Earth, this sharp 27 frame mosaic [
http://www.robgendl…] of M33 nicely shows off blue star clusters and pinkish star forming regions which trace the galaxy's loosely wound spiral arms. In fact, the cavernous NGC 604 [
http://antwrp.gsfc.…] is the brightest star forming region seen here, visible along an arm arcing above and to the right of the galaxy center. Like M31, M33's population of well-measured variable stars have helped make this nearby spiral a cosmic yardstick [
http://cfa-www.harv…] for establishing [
http://adsabs.harva…bib_query?1926ApJ... .63..236H ] the distance scale [
http://antwrp.gsfc.…debate96.html ] of the Universe.
Explanation
The small constellation Triangulum [
http://www.hawastso…] in the northern sky harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy [
http://www.seds.org…]. M33's diameter spans over 50,000 light-years, making it third largest in the Local Group [
http://www.anzwers.…] of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 lies very close to the Andromeda Galaxy [
http://antwrp.gsfc.…] and observers [
http://www.astr.ua.…] in these two galaxies would likely have spectacular views of each other's grand spiral star systems. As for the view from planet Earth, this sharp 27 frame mosaic [
http://www.robgendl…] of M33 nicely shows off blue star clusters and pinkish star forming regions which trace the galaxy's loosely wound spiral arms. In fact, the cavernous NGC 604 [
http://antwrp.gsfc.…] is the brightest star forming region seen here, visible along an arm arcing above and to the right of the galaxy center. Like M31, M33's population of well-measured variable stars have helped make this nearby spiral a cosmic yardstick [
http://cfa-www.harv…] for establishing [
http://adsabs.harva…bib_query?1926ApJ... .63..236H ] the distance scale [
http://antwrp.gsfc.…debate96.html ] of the Universe.
Explanation
