Triangulum Galaxy Image Highlights Local Group’s Third Largest Spiral
NASA’s Astronomy Picture of the Day features a new telescopic image of Messier 33, also known as the Triangulum Galaxy. Located approximately 3 million light-years from the Milky Way, this face-on spiral galaxy is over 50,000 light-years in diameter. It ranks as the third-largest galaxy in the Local Group, behind only the Milky Way and Andromeda. The image, credited to George Chatzifrantzis, displays blue star clusters and pinkish star-forming regions along loosely wound spiral arms. Notably, the bright star-forming region NGC 604 is visible near the 5 o'clock position from the galaxy center. M33 is believed to be a satellite of the Andromeda Galaxy, meaning observers in both systems would likely see each other’s grand spirals clearly. Variable stars in M33 have historically served as cosmic yardsticks for establishing the universe’s distance scale.
