While it is possible to observe the Triangulum Galaxy under excellent dark-sky conditions, the human eye will only see it as a faint, blurry object with an ethereal glow in the Triangulum (the Triangle) constellation. 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. By comparison, the Andromeda Galaxy is 200,000 light-years across and the Milky Way is 100,000 light-years in diameter.
Astronomers have pieced together a massive mosaic of the nearby Triangulum Galaxy from images taken by the Hubble Space Telescope.
This is the second-largest image ever released by Hubble and shows Triangulum's central region as well as its inner spiral arms. Some 1500 light-years across, this is one of the largest, brightest concentrations of ionized hydrogen (H II) in our Local Group of galaxies, and it is a major center of star formation. According to Science Daily, it has one order of magnitude fewer stars than the Milky Way. The image is comprised of 665 million pixels and was created from 54 different images, a view in space so large that it spans "an area more than 19,000 light-years across".
Another difference between the Triangulum Galaxy and the two more popular spiral galaxies is that the former does not have a bright bulge in its center.
The Hubble Space Telescope is the most significant piece of equipment the United States space agency has ever sent to space.
Andromeda and the Milky Way also surpass the Triangulum Galaxy in terms of the number of stars they contain. That huge amount of gas and dust allows for rapid star formation, at a rate of approximately one solar mass every two years.
Still, Messier 33 remains an important find, its abundance of gas clouds drawing astronomers to conduct this detailed analysis.
The Triangulum Galaxy - also known as Messier 33 or NGC 598 - is part of the "Local Group", meaning it is part of the same group of galaxies that the Milky Way belongs to.
Which is weird, because newborn stars devour dust and gas, leaving less fuel for new celestial bodies to emerge.
Many other Hubblecast episodes are also available.