Some stars strip their planets' atmosphere — a new NASA telescope image pinpoints when
The Chandra image sets a timestamp on when young stars stop bullying their baby worlds.
Young stars can erase the atmospheres of their planets. Recently, astronomers made headway into their investigation of these stars’ potency.
To learn about these magnetically-active stars, billions of years younger than the Sun and capable of zapping their planets, researchers zeroed in on open clusters. They house thousands of stars. Their common age and environment sets the stage for a good analysis of their lives and evolution.
The best tool that Konstantin Getman, a research professor at Penn State University, and his colleagues had to use was the Chandra X-ray Observatory. That’s because stars with higher magnetic-field activity appear brighter in X-rays, according to a December 15 announcement from NASA. They also harnessed data from the European Space Agency’s Gaia spacecraft, currently on a quest to survey a billion stars in our galaxy. It helped Getman’s team ascertain which stars belonged to the clusters, and which ones were just foreground and background visual stragglers.
NASA’s announcement highlights one of the 10 different open clusters the team studied, designated NGC 3293. This region almost looks like a flower, as pink material, apparent in infrared, fans out like blooming petals. In a composite image from NASA, the glittery sepal — the bright purple points at the center of the image — is the X-ray data.
After analyzing stars across these clusters, plus some ultra-young 500,000 year-old stars from earlier Chandra studies, Getman team arrived at some conclusions.
According to NASA, the team found that X-ray brightness from Sun-like stars teeters off when they become 7 million years old. The star cluster NGC 3293 is at that transitional stage.
Before this milestone, the juvenile stars were “boisterous” and capable of “halting the growth of planets,” NASA wrote.
And some stars in this mesmerizing scene are still “extremely active.” The X-rays and ultraviolet barrage from these stars could sweep away planetary building blocks from the space around them. The radiation could also evaporate a planet’s atmosphere, either partially or entirely.
So the verdict is that this luscious scene is no place to live.