The small, northern constellation Triangulum [
http://www.hawastso…] 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 is over 50,000 light-years in diameter, third largest in the Local Group [
http://atlasoftheun…] of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy [
http://antwrp.gsfc.…] and astronomers [
http://arxiv.org/ab…] 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 detailed, wide field image [
http://www.tvdavisa…] nicely shows off M33's blue star clusters and pinkish star [
http://www.astropix…] 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 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 [
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, northern constellation Triangulum [
http://www.hawastso…] 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 is over 50,000 light-years in diameter, third largest in the Local Group [
http://atlasoftheun…] of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy [
http://antwrp.gsfc.…] and astronomers [
http://arxiv.org/ab…] 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 detailed, wide field image [
http://www.tvdavisa…] nicely shows off M33's blue star clusters and pinkish star [
http://www.astropix…] 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 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 [
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
