This image of the Triangulum Galaxy is a composite of about 54 different pointings with Hubble's Advanced Camera for Surveys. Hubble has just released its most detailed view yet of that galaxy, which is known as Triangulum (can you see why?).
It's our neighbor in a collection of dozens of galaxies called the Local Group, and was captured in unprecedented detail in image consisting of 54 Hubble fields of view stitched together, revealing almost 25 million individually resolved stars. Millions of stars, hundreds of star clusters and bright nebulae are visible. He subsequently documented when in their history these Local Group dwarf galaxies stopped making stars, or "quenched", and how this was affected by the proximity of the larger galaxies, including the Milky Way.
Triangulum is perfectly positioned for astronomers to study and compare to both our own Milky Way galaxy and one of our other neighbors, Andromeda, as it faces directly towards us, showcasing its near-perfect distribution of stars along its well-defined spiral structure.
A separate statement noted that "as the junior member of this trio of spiral galaxies, Triangulum provides the valuable comparisons and contrasts that only a close companion can". "The star formation rate intensity is 10 times higher than the area surveyed in the Andromeda galaxy in 2015".
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 near-perfect distribution of stars within Triangulum has led researchers to believe that the galaxy has somehow avoided any major intergalactic collisions and has remained relatively untouched for aeons.
It also has at least an order of magnitude less stars than the Milky Way and two orders of magnitude less than Andromeda.
The galaxy contains a huge amount of gas and dust, giving rise to rapid star formation.
Usually when astronomers talk about our neighbouring galaxy, they're talking about Andromeda, which is a cozy 2.5 million light-years away.
Hubble takes images in incredibly high resolution, of course, but it's not the only telescope that can observe this galaxy.