COLLECTION NAME:
NASA Astronomy Picture of the Day Collection
Record
Title:
M33: Spiral Galaxy in Triangulum
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.
facet_where:
Andromeda Galaxy
facet_what:
Andromeda
UID:
SPD-APOD-ap030924
