As planetary demises go, this one is pretty grisly: a planet falls closer and closer to its host star, getting hotter and hotter as it spirals inward, until it finally falls past the point of no return and is swallowed by the star in a tremendous flash of light. That’s what happened in an event called ZTF SLRN-2020, and now the James Webb Space Telescope has been observing the aftermath to learn more about this rare event.
“Because this is such a novel event, we didn’t quite know what to expect when we decided to point this telescope in its direction,” said lead researcher Ryan Lau of NOIRLab, who used Webb’s MIRI (Mid-Infrared Instrument) and NIRSpec (Near-Infrared Spectrograph) instruments to make observations. “With its high-resolution look in the infrared, we are learning valuable insights about the final fates of planetary systems, possibly including our own.”
Astronomers had originally thought that the planet was destroyed when the star swelled up and engulfed it. But now, with the new data, they think that the planet spun inward toward the star until it was swallowed.
“The planet eventually started to graze the star’s atmosphere. Then it was a runaway process of falling in faster from that moment,” said researcher Morgan MacLeod of the Harvard-Smithsonian Center for Astrophysics. “The planet, as it’s falling in, started to sort of smear around the star.”
When the planet finally fell in toward the star, it splashed away layers of gas from the star’s outer atmosphere, and this gas gradually cooled into cold dust which now sits as a cloud around the star. Within this cold dust, there is a smaller disk of hot gas closer in, which includes carbon monoxide.
“With such a transformative telescope like Webb, it was hard for me to have any expectations of what we’d find in the immediate surroundings of the star,” said researcher Colette Salyk of Vassar College. “I will say, I could not have expected seeing what has the characteristics of a planet-forming region, even though planets are not forming here, in the aftermath of an engulfment.”
It’s extremely rare to find an event like this, but the researchers are hoping they will be able to observe more similar events in the future, using both Webb and upcoming telescopes like the Vera C. Rubin Observatory and NASA’s Nancy Grace Roman Space Telescope.
“This is truly the precipice of studying these events. This is the only one we’ve observed in action, and this is the best detection of the aftermath after things have settled back down,” Lau said. “We hope this is just the start of our sample.”
The research is published in in The Astrophysical Journal.
After 13 suborbital test flights and more than $15 billion in development costs, SpaceX's Starship has finally reached orbit. The 407-foot megarocket, the most powerful ever built, lifted off from Starbase, Texas, on Monday and delivered its first real payload on it's 14th attempt. The celebration came with an asterisk, though, since SpaceX had to cut the planned 10-hour mission to roughly three hours.
https://twitter.com/SpaceX/status/2104601695711904180
SpaceX is finally ready to give Starship its biggest test yet. The company says the massive rocket's 14th test flight is scheduled for September 22, when it will attempt to put the upper stage into Earth orbit for the first time. The launch is currently pending regulatory approval, with a 75-minute window opening at 7:15 a.m. CT.
Starship has 26 Starlink satellites to deliver
For decades, humanity has looked up at the Moon and wondered what it would be like to live on it. Think sprawling cities, factories, research centers, and permanent human settlements. Unfortunately, there is one fairly fundamental problem with that vision.
A new study published in Frontiers in Space Technologies argues that even the Moon's potentially enormous reserves of frozen water may be nowhere near enough to support city-sized populations sustainably. Researchers Martin Elvis and Jonathan McDowell estimate that the permanently shadowed regions near the lunar poles could contain roughly one billion tons of water. It sounds like an extraordinary amount until you put a million thirsty humans next to it.