Dragonfly 44 Galaxy's discovery was announced on Thursday, Aug. 25. The scientists revealed that the galaxy has the same mass as the Milky Way but contains 99.99 percent dark matter. This dark matter is an elusive and undetected substance.
The Dragonfly 44 was first detected in Toronto through the Dragonfly Telephoto Array in Toronto. After the detection, the scientists used the Gemini North telescope at the Gemini Observatory and the Keck II telescope at the W.M. Keck Observatory, the world's most powerful telescopes, to monitor and confirm it further, reported Tech Times.
Although the galaxy is not the first to be identified with presence of dark matter, its discovery is special because it is the only average-sized galaxy nearly dominated by dark matter. Pieter van Dokkum, an astronomer from Yale University, said that the galaxy has much more to reveal than what meets the eye, reported Sci-fi News.
Dragonfly 44 Has Unidentified Dark Matter
Dragonfly 44 is about 300 million light-years away from Earth. This newly discovered galaxy is considered a dim galaxy as it has very few stars. According to van Dokkum, there must be something that holds it together as there are only few stars and it would have rapidly ripped apart otherwise.
It is believed that the Dragonfly 44 is likely made up of dark matter because the velocities of stars within it are much higher than what they had expected. This indicates that it has a mass greater than what can be detected through telescopes. Furthermore, even if Dragonfly 44 has the same mass as Milky Way but contrary to our galaxy, it is dark and hence called the "Dark Twin." Also, it differs from our galaxy by a factor of 100.
Discovery of Dragonfly 44 Changes Everything
The discovery of Dragonfly 44 is very new to the existing line of research that astrophysicists currently study. According to van Dokkum, the existing notions on the formations of galaxies are challenged by the discovery of Dragonfly 44. Scientists thought the ratio of dark matter was something they already understood prior to the discovery.
To cite an example, it was assumed that the dark matter is thought to outnumber regular matter by 5 to 1 in the universe. Also, it was of the notion that the formation of stars was related to how much dark matter is present. However, Dragonfly 44 shattered these theories. "It means we don't understand, kind of fundamentally, how galaxy formation works," says van Dokkum.
It is believed that the dark matter emits a faint ultraviolet signal. So, the scientists across the world are in a race to detect other galaxies similar to Dragonfly 44. They are eager to get hands on information by discovering a neighboring galaxy with dark matter. This might increase the chances of providing evidence of the elusive substance's existence.
