Astronomers have caught a star devouring one of its planets for the first time. One day our own sun will expand like this star, enveloping the other inner planets, so this system is a kind of glimpse into Earth’s destiny.
Kishalay From at the Massachusetts Institute of Technology and his colleagues used the Zwicky Transient Facility in California to spot a strange burst of light that was designated ZTF SLRN-2020, coming from a star about 13,000 light-years away. Over the course of about 10 days it cleared up by a factor of about 100.
The explosion was similar to a phenomenon called a red nova, caused by a merger between two stars, but it wasn’t as bright and didn’t release as much energy. After collecting more observations with other telescopes, the researchers found that the data was consistent with a star consuming not another star, but a gas giant planet at least 30 times the mass of Earth.
We knew that stars eat planets because we saw the consequences of stars being polluted with chemicals from the worlds they devoured. “In the past, all the evidence we’ve had of stars eating planets comes from observing stars that did so hundreds of thousands of years ago,” De explains. have never caught a star in the act of eating a planet.”
This is expected to happen when a sun-like star depletes its hydrogen and transitions to helium fusion. In the process, the star becomes a red giant and its atmosphere expands outward, swallowing up all the planets with the misfortune of orbiting too close. In the case of ZTF SLRN-2020, the planet took less than one Earth day to orbit its star.
The sun is expected to begin expanding in about 5 billion years. “We’re actually seeing the fate of our own planet happening in real time on another unfortunate planet,” De says. sun would also shine in the same way, but the effect would be nowhere near as dramatic because the Earth is so much smaller than [the planet] East.”
Now that we know what a planetary engulfment looks like, it will be much easier to search for them and study them in more detail, says De. The researchers calculated that it should happen about once a year in our galaxy, we should therefore be able to find more planets being eaten up by their stars, as well as continue to observe this one and determine the details of the process – and Earth’s future demise.