TCU astronomer Kat Barger shines a light on the Milky Way’s origins
(This article by Rebecca Boyle previously appeared in the Fall 2017 issue of “TCU Magazine.”
About 4 1/2 billion years ago, at cosmic distances that are difficult to fathom, a star collapsed in on itself and exploded. Within 20 minutes of the core’s collapse, a shockwave streamed through the star’s surface in a burst of light that shone 130 million times brighter than the sun.
Gravity drew those gases together into what’s called a molecular cloud, pushing them closer and closer until they grew denser and collapsed, much like the supernova that produced them. As more gas collected, it started to spin, eventually flattening into a disk like a pancake. At its center burned the faint young sun.
If that distant supernova had not exploded, the gas that became the sun and solar system might not have made it into the Milky Way. It might have remained in a much more distant galaxy, never to travel through intergalactic space and eventually become planets and asteroids and people.
Supernovae are vital movers of the gas that powers galaxies, said Kat Barger, assistant professor of astronomy at TCU. “You need gas to make stars. We are tracking the star-formation ability of galaxies.”
Barger’s research at TCU focuses on tracing the journey of this gas, especially gas found in the Large Magellanic Cloud, a small companion galaxy to the Milky Way. From the Southern Hemisphere, the Large and Small Magellanic Clouds are visible as purplish smudges of light, but they are actually distant dwarf galaxies.
Reach for the stars and learn more in “TCU Magazine.”