For the first time ever, astronomers were able to see a planet being consumed by a dying star. Up until this point, scientists have only observed the moments before and after a star engulfs a planet.
When stars run out of fuel, they grow exponentially and swallow all the matter in their vicinity, including planets, according to a press release from MIT . New research on the planet-engulfing-star was published in Nature by a team from MIT, Harvard University, and Caltech.
“For decades, we’ve been able to see the before and after,” explained lead author Kishalay De, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. “Before, when the planets are still orbiting very close to their star, and after, when a planet has already been engulfed, and the star is giant. What we were missing was catching the star in the act, where you have a planet undergoing this fate in real-time. That’s what makes this discovery really exciting.”
The incident seems to have occurred in the Milky Way galaxy approximately 12,000 light-years away near the Aquila constellation. Over the course of 10 days, scientists watched a star get 100 times brighter than usual and then disappear. The white-hot flash preceded a cold, long-lasting signal. Researchers believe the event was a star overtaking a nearby planet.
According to De, the team observed the “end-stage of the swallowing.”
Scientists believe the planet was the size of Jupiter. It spiraled close to the dying star and was pulled into its atmosphere before being consumed. In five billion years, Earth will likely be subjected to the same end when the sun burns out and swallows the Milky Way’s inner planets.
“If some other civilization was observing us from 10,000 light-years away while the sun was engulfing the Earth, they would see the sun suddenly brighten as it ejects some material, then form dust around it, before settling back” De explained.
The astronomers initially noticed the planet-swallowing event in May 2020 through data from the Zwicky Transient Facility (ZTF) at Caltech’s Palomar Observatory in California. The ZTF looks for supernovae, gamma-ray bursts, and other events in the sky. Additional data was analyzed from the Keck Observatory in Hawaii, and one year later, an infrared camera from the Palomar Observatory.
“That infrared data made me fall off my chair,” De noted. “The source was insanely bright in the near-infrared.”
The star initially burned hot but then emitted colder energy over the period of a year. Using data from NASA’s infrared space telescope, NEOWISE, astronomers determined that the total energy the star released after its outburst was 1,000-times smaller than what they had previously observed.
“That means that whatever merged with the star has to be 1,000 times smaller than any other star we’ve seen,” De explained. “And it’s a happy coincidence that the mass of Jupiter is about 1/1,000 the mass of the sun. That’s when we realized: This was a planet, crashing into its star.”
Will Earth’s inhabitants be able to escape before the sun swallows our planet five billion years from now? Perhaps alien assistance will be required. And by then, there is a good chance we will have made first contact with them.
Extraterrestrial life may learn about our presence in the galaxy sooner rather than later. New research from The University of Manchester and the University of Mauritius indicates that aliens may discover humans due to leaked radio signals from cell phone towers.
According to Professor Mike Garrett, Team Leader of the project and Director of Jodrell Bank Centre for Astrophysics at The University of Manchester, “Current estimates suggest we will have more than one hundred thousand satellites in low Earth orbit and beyond before the end of the decade. The Earth is already anomalously bright in the radio part of the spectrum; if the trend continues, we could become readily detectable by any advanced civilization with the right technology.”
Dr Nalini Heeralall-Issur, Saide’s supervisor and Associate Professor at the University of Mauritius, added: “I believe that there’s every chance advanced civilizations are out there, and some may be capable of observing the human-made radio leakage coming from planet Earth.”
