For the first time, astronomers have caught a star in the act of eating a planet. The star known as ZTF SLRN-2020, exists approximately 12,000 light years away in our galaxy.
“For decades, we’ve been able to see the before and after,” says study leader Kishalay De. “Before, when the planets are still orbiting very close to their star, and after, when a planet has already been swallowed up, and the star is giant. What we were missing was catching the star in the act, where you have a planet going through this fate in real time. That’s what makes this discovery really exciting.”
In 2020, De was studying data, hoping to find evidence of two stars combining with each other. This usually results in bursts of light thousands of times brighter than the stars themselves. But one shining star De discovered was much dimmer (黯淡的), only 100 times brighter. Also, the crash of two stars usually produces hot gas. However, this one was surrounded by dust molecules (分子). De wondered if he had detected a star swallowing a planet.
He and his team spent the next two years examining similar data. NASA provided the final piece of evidence they needed. The images allowed them to confirm that the molecules were traces of a star eating its planet. The scientists said that as the planet was being swallowed, it displaced hot gas from the star. The gas then cooled and created dust. Pieces of the planet also blew away from the star, producing more dust.
Some scientists believe Earth will also be consumed by the Sun in about five billion years. But Mansi Kasliwal, a professor, says humans will not be around then. The increasing heat from the expanding Sun will evaporate (使蒸发) all the water from Earth long before it gets close enough to swallow it, making it uninhabitable. Smadar Naoz, an astronomer, agrees that the Earth’s water sources will dry up. “Whether or not the Sun will swallow the Earth is quite controversial,” she says. “But it wouldn’t matter because it will no longer be our beautiful Earth with an atmosphere and oceans.”
【小题1】What fate does De think the planet is undergoing?| A．It is being swallowed. | B．It is being abandoned. |
| C．It is becoming larger. | D．It is growing older. |
| A．Hot gas. | B．Dust molecules. |
| C．Pieces of a planet. | D．Bursts of brighter light. |
| A．The Earth will be eaten by the Sun. | B．Humans will move to another planet. |
| C．The water on Earth will disappear. | D．The Earth will become more beautiful. |
| A．Scientists Make an Unusual Discovery |
| B．Stars and Planets Are Born and Die |
| C．The Earth Will Not Be Eaten by the Sun |
| D．Astronomers Detect a Star Swallowing a Planet |
