To make a star, the universe needs three ingredients: gravity, turbulence, and a magnetic field.

The combination of these forces—along with a mixture of gas and dust—creates the necessary conditions for those twinkling, bright balls of light to take hold in the sky. For years, astronomers have been probing the galaxy to understand the role each factor plays when a star is born.

Now, one piece of the puzzle just became a bit clearer.

In a paper published in Nature Astronomy in August 2020, BU astronomer Thushara Pillai found that magnetic fields within molecular clouds—formations made of cosmic dust and gas—help feed young, growing stars. A College of Arts & Sciences senior research scientist at BU’s Institute for Astrophysical Research, Pillai made the discovery by observing star formation in Serpens South, a nearby cluster of about 60 young stars, some 1,400 light-years away from Earth. By using high-resolution telescope images of polarized infrared light, Pillai was able to pinpoint where the magnetic field surrounding the group of stars becomes weaker, changes direction, and is pulled back toward the cluster along with the surrounding particles and dust.

Pillai’s research helps solve some of the mysteries about how stars come to be and to what extent molecular clouds in interstellar space play a role. “The change in direction of the magnetic field,” she says, “that is what is new about this science.”