Researchers have observed a number of galaxies that do not contain the large clusters of stars commonly found in other galaxies. (Credit: Shutterstock)
While stars often light up the night sky, there are hundreds of galaxies across space with no lights at all.
Many researchers have recently discovered several dimly lit galaxies scattered throughout space that have a surprising lack of stars.
These “dark galaxies” have only a small glimmer of starlight from a tenuous blob as opposed to radiant balls of densely packed stars in more prominent galaxies.
According to an article in Science News, it is unclear how the dark galaxies have formed but they could be a new type of galaxy that challenges ideas about the birth of galaxies. Another possibility is the dark galaxies might be outliers of already familiar galaxies.
The observation of dark galaxies has confused researchers because those the size of the Milky Way aren’t thought of as having trouble creating a significant amount of stars, which has led to theories that the star-less entities are failed galaxies or relative lightweight galaxies that are stretched thin by internal or external forces.
However, according to the article, no matter how these galaxies are formed—they must contain an enormous deposit of unseen matter to resist being pulled apart by the gravity of other galaxies.
With so much unknown, astronomers from everywhere from France to Canada to America are attempting to study it further and come up with an explanation for the power outage in certain galaxies that likely have been lurking for billions of years.
Astronomers first began to notice these galaxies in 2013 using telescopes designed to detect faint objects and since then have noticed several more scattered throughout the cosmic neighborhood.
Roberto Abraham, an astrophysicist at the University of Toronto, said in the Science News article that 47 dark galaxies were initially discovered in the Coma Star Cluster, many of which are similar in size to the Milky Way.
Abraham said it is surprising that the dark galaxies survive in Coma because it is crowded with “galactic bullies” since a galaxy’s own gravity holts it together, but gravity from neighboring galaxies can pull hard enough to apart a smaller one. In order to create enough gravity to survive, a galaxy needs mass in the form of stars, gas and cosmic matter and with so few stars’ dark galaxies would be particularly susceptible to being shredded apart by more powerful neighboring ones.
Another group led by Jim Koda, an associate professor at Stony Brook University, was able to confirm the 47 dark galaxies and an additional 854 dark galaxies and he also calculated that Coma could hold more than 1,000 dark galaxies of all sizes.
