If we could travel to within a few light hours. . . of this system. . . what a fireworks show we would witness.
The very young (less than 100 million years old) system features a close orbiting world, that is being shredded in the upper atmosphere, at least, by gouging electromagnetic swirls from the very nearby star. It might look lik a freight train on the tracks, during a foggy night -- with a glowing beacon ahead as well as behind it, as it passed in front of the host star. . . as imaged by NASA artists at right. Here's the full story:
. . .NASA's Hubble Space Telescope [recently observed that] the planet looked like it wasn't losing any material at all, while an orbit observed with Hubble a year and a half later showed clear signs of atmospheric loss.
This extreme variability between orbits shocked astronomers. "We've never seen atmospheric escape go from completely not detectable to very detectable over such a short period when a planet passes in front of its star," said Keighley Rockcliffe of Dartmouth College in Hanover, New Hampshire. "We were really expecting something very predictable, repeatable. But it turned out to be weird. When I first saw this, I thought 'That can't be right.'"
Rockcliffe was equally puzzled to see, when it was detectable, the planet's atmosphere puffing out in front of the planet, like a headlight on a fast-bound train. "This frankly strange observation is kind of a stress-test case for the modeling and the physics about planetary evolution. This observation is so cool because we're getting to probe this interplay between the star and the planet that is really at the most extreme," she said.
Located 32 light-years from Earth, the parent star AU Microscopii (AU Mic) hosts one of the youngest planetary systems ever observed. The star is less than 100 million years old (a tiny fraction of the age of our Sun, which is 4.6 billion years old). The innermost planet, AU Mic b, has an orbital period of 8.46 days and is just 6 million miles from the star (about 1/10th the planet Mercury's distance from our Sun). The bloated, gaseous world is about four times Earth's diameter. . . .
[This local star's solar] flares are powered by intense magnetic fields that get tangled by the roiling motions of the stellar atmosphere. When the tangling gets too intense, the fields break and reconnect, unleashing tremendous amounts of energy that are 100 to 1,000 times more energetic than our Sun unleashes in its outbursts. It's a blistering fireworks show of torrential winds, flares, and X-rays blasting any planets orbiting close to the star. "This creates a really unconstrained and frankly, scary, stellar wind environment that's impacting the planet's atmosphere," said Rockcliffe. . . .
Now you know -- be excellent to one another, as ever. . . smile.
नमस्ते
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