The Hubble Space Telescope has captured the most detailed image yet of the Triangulum Galaxy, a spiral galaxy neighboring the Milky Way, in a panoramic survey that contains an estimated 40 billion stars. The image has an astonishing 665 million pixels and shows the galaxy’s central region (bright, yellow-hued center) surrounded by its inner spiral arms. It’s made up of around 54 different images captured by Hubble that were subsequently stitched together in a joint effort by the European Space Agency (ESA) and NASA.
A second image shows NGC 604, also located within the Triangulum Galaxy. Measuring 1,500 light-years across, it’s one of the largest and brightest concentrations of ionized hydrogen (H II) in our “Local Group” of galaxies and also a major center of star formation. Here, gas is nine-tenths hydrogen, allowing for a slow collapse under the force of gravity to create new stars that, once formed, emit ultraviolet radiation. Hubble first captured this object in 2003 and again in 2010, illustrated by different colors due to a different filter.
Videos posted by the space agencies offer an even deeper perspective into the nearby Triangulum spiral, which is the second closest large galaxy to our own. Below you can see the many glowing gas clouds in the spiral arms with “particular clarity”, packed with bright star clusters and clouds of gas and dust.
Located some 3 million light-years from our home planet, the Triangulum Galaxy – also known as Messier 33 or NGC 598 – is one of the most distant objects visible to the naked eye. If you’re standing here on Earth, it is characterized by a faint, blurry glow. Clocking in as the third largest galaxy in our Local Group, it contains fewer stars than the Milky Way and has a lesser magnitude than Andromeda.
Though Triangulum doesn’t have a bright bulge at its center and lacks a bar connecting its spiral arms to the center, it contains a huge amount of gas and dust that rapidly gives rise to the formation of new stars at a rate of about one solar mass every two years. And, because a star is born by using the material in clouds and dust, scientists say studying this region could help us understand how stars form and evolve.