 Here we are zooming into the Triangulum Galaxy. It's the third largest member of the local group. With a diameter of about 60,000 light-years, Triangulum is home to around 40 billion stars. That small compared to our 2 to 400 billion and Andromeda's trillion, the galaxy doesn't have a bright bulge at its center. But it does contain a huge amount of gas and dust, giving rise to rapid star formation. New stars form at a rate of approximately 1 every 2 years. This Hubble image contains 10 to 15 million individual stars. The mosaic of the Triangulum Galaxy showcases the central region of the galaxy and its inner spiral arms. Millions of stars, hundreds of star clusters, and bright nebula are visible. NGC 604 is among the largest known star formation regions in the local group. It lies in an outer Triangulum spiral arm. This huge star birth region contains more than 200 brilliant blue stars within a cloud of glowing gas some 1,500 light-years across. That's nearly 100 times the size of the Orion Nebula. By contrast, the Orion Nebula contains just four bright central stars. The bright stars in 604 are extremely young by astronomical standards, having formed a mere 3 million years ago.