Explanation:
The small northern constellation Triangulum is home to the beautiful face-on spiral galaxy, Messier 33 (also known as the Pinwheel Galaxy or Triangulum Galaxy). Measuring over 50,000 light-years in diameter, it ranks as the third largest galaxy in the Local Group, following the Andromeda Galaxy (M31) and our own Milky Way. Positioned approximately 3 million light-years away from the Milky Way, M33 is believed to be a satellite of Andromeda. Astronomers in these galaxies would enjoy spectacular views of each other’s spiral structures.
From our vantage point in the Milky Way, a detailed telescopic image of M33 reveals its vibrant blue star clusters and pink star-forming regions along its loosely wound spiral arms. Notably, NGC 604, the brightest star-forming region within M33, is located at about the 5 o’clock position relative to the galaxy’s center.
Like M31, M33’s well-documented variable star population aids astronomers in determining cosmic distances, establishing a crucial scale for the universe.
Additional Information:
- APOD’s main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod
- Tomorrow’s picture: star party weekend
