Astronomers using the NASA/ESA Hubble Space Telescope have taken a detailed image of a spectacular central part of the Triangulum Galaxy.
The Triangulum Galaxy is the third largest galaxy in our Local Group of galaxies. Image credit: NASA / ESA / M. Boyer, STScI / J. Dalcanton, University of Washington / Gladys Kober, NASA & Catholic University of America.
Otherwise known as Messier 33, M33 or NGC 598, the Triangulum Galaxy is a spiral galaxy located at a distance of some 3 million light-years.
Under excellent dark-sky conditions, this galaxy can be seen with the naked eye as a faint, blurry object in the constellation of Triangulum, where its ethereal glow is an exciting target for amateur astronomers.
The galaxy is a notable member of the Local Group of galaxies, an assembly of more than 50 galaxies bound together by gravity. It is the group’s third-largest galaxy, but also the smallest spiral galaxy in the group.
The Triangulum Galaxy measures only about 60,000 light-years across, compared to the 200,000 light-years of the Andromeda galaxy; the Milky Way lies between these extremes at about 100,000 light-years in diameter.
“The Triangulum Galaxy is known to be a hotbed of starbirth, forming stars at a rate 10 times higher than the average of its neighbor, the Andromeda galaxy,” Hubble astronomers wrote in a statement.
“Interestingly, its neat, organized spiral arms indicate little interaction with other galaxies, so its rapid starbirth is not fueled by galactic collision, as in many other galaxies.”
“The galaxy contains plenty of dust and gas for churning out stars, and numerous ionized hydrogen clouds, also called HII regions, that give rise to tremendous star formation.”
“Researchers have offered evidence that high-mass stars are forming in collisions between massive molecular clouds within the Triangulum Galaxy.”
This new image from Hubble captures reddish clouds of ionized hydrogen interspersed with dark lanes of dust. The apparent graininess of the image is actually swarms of countless stars.
“The Triangulum Galaxy is one of less than 100 galaxies close enough for telescopes like Hubble to resolve individual stars, as evident here,” the astronomers wrote.
“The galaxy is known to lack a central bulge, and there is no evidence of a supermassive black hole at its core — strange since most spirals have a central bulge made up of densely concentrated stars and most large galaxies have supermassive black holes at their centers.”
“Galaxies with this type of structure are called pure disk galaxies, and studies suggest they make up around 15-18% of galaxies in the Universe.”
“The Triangulum Galaxy may lose its streamlined appearance and undisturbed status in a dramatic fashion — it’s on a possible collision course with both the Andromeda galaxy and the Milky Way.”
“This image was taken as part of a survey of the Triangulum Galaxy in an effort to help refine theories about such topics as the physics of the interstellar medium, star-formation processes, and stellar evolution.”