Chinese astronomers discover new ultra-faint galaxy KK153

Chinese astronomers have discovered a new ultra-faint dwarf galaxy, named KK153, using the Five-hundred-meter Aperture Spherical Telescope (FAST). This finding, reported on March 12, highlights that the galaxy is rich in gas. Ultra-faint dwarf galaxies are known for being very dim and dominated by dark matter. They are important to astronomers as they represent early stages of the universe. A team led by Jin-Long Xu from the Chinese Academy of Sciences is conducting a survey to find such galaxies. In their research, the team looked for compact gas clouds moving slowly. They detected a cloud with a speed of about 127 km/s and found KK153 at its center. The galaxy is located about 6.5 million light-years away. KK153 has a radius of about 682 light-years. Its stellar mass is roughly 410,000 solar masses, while the mass of its hydrogen gas is about 520,000 solar masses. This means nearly 63% of the galaxy's mass comes from gas. The researchers also found that KK153 has a cool and warm gas medium, typical for gas-rich galaxies. Additionally, it has many blue stars, indicating recent star formation, along with some red stars. This discovery sheds light on the diversity of galaxies in the universe.