A big surprise for scientists, a new discovery concerning a small galaxy orbiting the Milky Way has just shown that this small galaxy has a giant black hole in its center. This black hole would even be comparable to the one in the middle of our galaxy, and researchers have no explanation for its existence.
The galaxy that amazes researchers is a dwarf galaxy named Leo I. It is located at a distance of 820,000 light years from Earth and its width is 2,000 light years. Until then, astronomers believed that Leo I had a mass equivalent to 15 to 30 million solar masses. For comparison, the Milky Way has a mass equivalent to 1.5 trillion solar masses for a diameter of 100,000 light years.
The discovery of the giant black hole thus surprised astronomers. Usually, black holes of this size are formed when galaxies collide. According to Maria José Bustamante, researcher in astronomy at the University of Texas, there is no explanation for this type of black hole in dwarf spheroidal galaxies.
Discovered by chance
According to reports, scientists discovered the existence of the giant black hole by chance. The researchers’ initial goal was to measure the amount of dark matter in Leo I using the Virus-W instrument from the 2.7m Harlan Telescope at the McDonald Observatory at the University of Texas. This instrument is used to measure the movement of stars in small galaxies around the Milky Way and to deduce the amount of dark matter based on the movements.
When the collected data was fed into the computer models, it appeared to astronomers that Leo I did not have dark matter but rather a black hole at its center with a mass similar to that of 3 million suns.
After obtaining these results, the scientists admitted that the results obtained in previous calculations regarding the amount of dark matter in the galaxy Leo I were different. They explained that previous studies were based on less precise data. Nor did they have access to supercomputers as powerful as those at the University of Texas.
Previously, astronomers who studied the Leo I galaxy had not seen the denser interior regions. They focused on the accessible data for individual stars. This data, however, contained a disproportionate number of slow stars. Calculations based on these data did not reveal dark matter in the interior regions. The amount of dark matter in the central regions of Leo I, which had not yet been observed, appears to be higher than what is at the edges.