South Middlesex Times

Leo P, a small galaxy located approximately 5.3 million light years from Earth, is providing new insights into star formation and galaxy growth. A study led by Kristen McQuinn, an associate professor at Rutgers University-New Brunswick and a scientist at the Space Telescope Science Institute, reveals that Leo P "reignited" during a crucial period in the universe's timeline, producing stars when many other small galaxies did not.

Using NASA’s James Webb Space Telescope, McQuinn and her team observed that Leo P underwent three phases: an initial burst of star formation, a long pause lasting several billion years, and a subsequent round of star formation still ongoing. This discovery helps astronomers understand the origins of the universe and the processes shaping it.

Discovered in 2013 by McQuinn and colleagues, Leo P resides in the constellation Leo. It is considered pristine due to its low levels of chemical elements other than hydrogen and helium. "Leo P provides a unique laboratory to explore the early evolution of a low-mass galaxy in detail," said McQuinn.

The research indicates that Leo P formed stars early but stopped during the Epoch of Reionization—a significant period occurring between 150 million and one billion years after the Big Bang—before reigniting billions of years later. This pattern contrasts with dwarf galaxies within the Local Group, where star production ceased entirely during this epoch.

McQuinn explained that environmental factors play a crucial role in whether a galaxy's star formation is quenched or continues. "If the trend holds, it provides insights on the growth of low-mass structures," she said.

Additionally, Leo P is found to be metal-poor with only 3% of the sun’s metallicity. This characteristic makes it similar to primordial galaxies from the early universe.

The study included contributions from Alyson Brooks, Roger Cohen, and Max Newman from Rutgers University's Department of Physics and Astronomy.