'300 light-years away': Scientists discover a new type of molecular gas cloud near the Sun
Produced by Tarun Mishra
Produced by Tarun Mishra
Astronomers have discovered a huge molecular gas cloud named Eos, located just 300 light-years away. The discovery could transform our understanding of the conditions needed for star formation in galaxies.
Stars form from clouds of molecular gas, but these clouds are incredibly faint when not energized by starlight. Traditional methods to detect them rely on tracing carbon monoxide, a common molecule in these clouds. However, Eos is depleted in carbon monoxide, making its detection more challenging.
Led by Blakesley Burkhart and Thavisha Dharmawardena, astronomers used far-ultraviolet data from the Korean STSAT-1 satellite to detect molecular hydrogen fluorescing. This is the first time such a method has been used to find a molecular cloud.
The Eos cloud is crescent-shaped and sits on the edge of the Local Bubble—a region of space with a lower density of interstellar gas. The cloud is glowing in the dark due to the far-ultraviolet fluorescence of hydrogen molecules.
Containing 3,400 solar masses worth of gas, Eos is predicted to disperse in about 5.7 million years due to the influence of background radiation. This means it will likely not form stars in the near future unless another event, like a gravitational disturbance from another cloud, triggers star formation.
The team’s discovery suggests that the dispersion of molecular clouds, triggered by photodissociation from nearby stars, could regulate the rate of star formation. This provides new insights into how star systems might form in distant, less observable regions of space.
The use of far-ultraviolet fluorescence could uncover similar molecular clouds across the galaxy. This breakthrough method could even extend our understanding of the interstellar medium back to the early universe, providing new details on how stars and planets form.