The first rocky planet to be observed orbiting a dying star, called a white dwarf, provides a glimpse of what planet Earth might be like in billions of years. It seems likely that our planet will survive the annihilation of the sun, but will only turn into a cold, devoid of humans in the future. Vast space.
A study using data from telescopes in the US state of Hawaii stated that the planet, whose mass is 1.9 times the mass of planet Earth, orbits a white dwarf about 4,200 light-years away from our solar system and is located near the center of our Milky Way galaxy.
A light year is the distance that light travels in a year, estimated at about 9.5 trillion kilometers.
The white dwarf began its life as a natural star one or two times larger than our sun. Its current mass is equal to half the mass of the Sun. Stars with a mass less than eight times the mass of the Sun at the end of their lives turn into white dwarfs, which is the most common type of stellar remnant.
Before its host star was annihilated, the planet orbited at a distance that likely put it in the “habitable zone,” that is, a place that is neither too hot nor too cold and where liquid water can exist on the surface, which could support life. It was originally orbiting at a distance approximately equal to the Earth’s distance from the Sun. After the death of its star, the distance increased 2.1 times the previous distance.
“It is currently a frozen world because the white dwarf, which is actually smaller than a planet, is very dim compared to its state when it was a normal star,” said Qiming Zhang, an astronomer at the University of California, San Diego. Zhang is lead author of the study published Thursday in the scientific journal Nature Astronomy.
It is planned that the sun, which is 4.5 billion years old, will turn into a white dwarf.
The end of the sun
“At the end of our sun’s life, it will grow to a massive size that astronomers call a red giant, and then it will gradually shed its outer layers,” said Jessica Lu, an astronomer at the University of California-Berkeley. “As our Sun loses mass, the size of the planets’ orbits will increase,” Lu, co-author of the study, added. “Eventually, the Sun will lose all of its outer layers and leave behind a hot, condensed core. This is called a white dwarf.”
Astronomers disagree about whether our planet will be swallowed up and destroyed when the Sun swells during its red giant phase, which is estimated to happen seven billion years from now. The sun will turn into a white dwarf a billion years after this happens.
“Theories vary on whether Earth will survive,” Chang said. “Venus will almost certainly be swallowed, while Mars will almost certainly survive. Our model shows that it is very likely that this planet’s orbit was similar to Earth’s orbit before the star transformed.” “The host of the planet has turned into a red giant, and this indicates that the chances of planet Earth’s survival may be greater than currently believed.”
So far, only gas giant planets larger than Jupiter, the largest planet in our solar system, have been observed orbiting white dwarfs.
The planet endured difficult times as its host star died.
“It may have turned into a molten planet when the star became a red giant, and then its temperature gradually decreased until it reached its current frozen state,” Zhang said.
Certain doom for humanity?
Zhang added that as the Sun ages and gets hotter, the solar system’s habitable zone will move away from its current state. The Earth will remain habitable for less than about a billion years from now, and the Earth’s oceans will likely have evaporated by that point.
Does this mean the certain destruction of humanity? Or the destruction of any life forms that will remain on planet Earth?
“We must have migrated from Earth before the billion-year time frame,” Zhang said.
Zhang emphasized that by the time the sun becomes a red giant, we may find refuge in specific huge moons in the outer range of our solar system, such as the moon “Ganymede” of the planet Jupiter and the moons “Titan” and “Enceladus” of the planet Saturn.
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