What is the largest planet discovered by man so far?

In 2006, American astronomers discovered a planet with the largest volume and the smallest density. Its diameter is one-third larger than Jupiter, the largest in the solar system. It is even less dense than ordinary wood, and some astronomers call it "like a big loose cork". If there is a tank big enough to hold it, it can float on the water.

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& ltbr & gt, the planet with the lowest density, was named HAT-P- 1, which was discovered with the help of a small automatic astronomical telescope observation network named HAT. HAT-P- 1 is about 450 light years away from the earth and revolves around a star in Scorpio. American astronomers think this is an unusually strange planet. They have never found such a strange celestial body before. Jasper Bacos, one of the designers of the HAT observation network, said: "Perhaps we have discovered a new type of planet this time."

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The diameter of & ltbr & gtHAT-P- 1 is 1.38 times that of Jupiter, but its density is only half that of Jupiter. If you can imagine putting Jupiter in a giant cosmic water cup, it will sink, but this new planet, if you imagine putting it in a cosmic water cup, it will float, and it will float very high, because its density is only a quarter of that of water. Compared with other planets, it is like a big loose cork.

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& ltbr & gtHAT-P- 1 differs from gas giants such as Jupiter and Saturn in that it has no solid core. This star is very close to its parent star, which is one seventh of the distance from Mercury to the sun, so the period of revolution of this planet is very short, only about 4.5 days. Scientists discovered this planet because the stars around it darkened when it flew by. That star is one of the binary systems, about 450 light years away from the earth. Although the characteristics of these two stars are very similar to those of the sun, they were formed about 900 million years later.

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& ltbr & gt What puzzles scientists is that the volume of HAT-P- 1 is much larger than predicted by current theory. Robert Ayers, an astronomer, said that the planet is so huge because its internal heat makes the whole star expand. However, scientists will further determine the exact reason why the density of HAT-P- 1 is particularly small.

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& ltbr & gt Recently, astronomers discovered the largest planet found outside our solar system. The temperature of this planet is between 1000 and 2000°C, and its gravity is 15 times that of the earth. Its year is only about 5.6 days on our planet. This strange gas planet, named HAT-P-2b, is located in Wuxian, 440 light years away.

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& ltbr & gt Astronomers at Harvard-Smithsonian Center for Astrophysics discovered this densely populated planet by using the global automatic telescope network system of HATNet. The network system can automatically scan the night sky to find exoplanets every night. HAT-P-2b is the second exoplanet discovered by this system.

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Gáspár Bakos, an astronomer at the & ltbr & gt Center for Astrophysics, said: "This planet is so unusual that at first we thought it was a false alarm, because many planets that look like planets were never discovered." His research team published this discovery in the journal Astrophysics.

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The & ltbr & gt research team can observe it as it orbits the earth to determine some of its characteristics. Bacos said: "We estimate that its gravity is very large, about 15 times that of the earth." This means that a person weighing 68kg on the earth can reach 950kg on the HAT-P-2b planet.

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& ltbr & gt Scientists also believe that the density of this planet is very high. Although the size of the HAT-P-2b planet is not much larger than Jupiter, the largest planet in our solar system, it is eight times heavier than Jupiter, equivalent to the mass of 2,500 earths.

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& ltbr & gtHAT-P-2b is very close to its orbit around the star, only 5 million kilometers, and its orbit is only 6.5438+0.5 million kilometers, so it takes only 5.6 days to make a revolution on the earth.

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& ltbr & gt Why does this strange phenomenon occur? Scientists think it is possible to hide another planet around it.

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& ltbr & gt Bacos said, "There may be a planet around HAT-P-2b that we haven't found interacting with."

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Researchers at & ltbr & gt said that the calculation concluded that such a strange super-density planet should be able to exist, and this new discovery just provided conclusive evidence.

& ltbr & gt Respondents: 0 Empty City Phantom 0- Probation Level15-1021:09

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& ltbr & gt Recently, American astronomers discovered a planet with the largest volume and the lowest density so far. Its diameter is one-third larger than Jupiter, the largest in the solar system. Its density is even smaller than that of ordinary wood.

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& ltbr & gt, the planet with the lowest density, was named HAT-P- 1, which was discovered with the help of a small automatic astronomical telescope observation network named HAT. HAT-P- 1 is about 450 light years away from the earth and revolves around a star in Scorpio. American astronomers think this is an unusually strange planet. They have never found such a strange celestial body before. Jasper Bacos, one of the designers of the HAT observation network, said: "Perhaps we have discovered a new type of planet this time."

& ltbr & gt

The diameter of & ltbr & gtHAT-P- 1 is 1.38 times that of Jupiter, but its density is only half that of Jupiter. If you can imagine putting Jupiter in a giant cosmic water cup, it will sink, but this new planet, if you imagine putting it in a cosmic water cup, it will float, and it will float very high, because its density is only a quarter of that of water. Compared with other planets, it is like a big loose cork.

& ltbr & gt

& ltbr & gtHAT-P- 1 differs from gas giants such as Jupiter and Saturn in that it has no solid core. This star is very close to its parent star, which is one seventh of the distance from Mercury to the sun, so the period of revolution of this planet is very short, only about 4.5 days. Scientists discovered this planet because the stars around it darkened when it flew by. That star is one of the binary systems, about 450 light years away from the earth. Although the characteristics of these two stars are very similar to those of the sun, they were formed about 900 million years later.

& ltbr & gt

& ltbr & gt What puzzles scientists is that the volume of HAT-P- 1 is much larger than predicted by current theory. Robert Ayers, an astronomer, said that the planet is so huge because its internal heat makes the whole star expand. However, scientists will further determine the exact reason why the density of HAT-P- 1 is particularly small. I think this question needs to be clear about what a planet is first.

& ltbr & gt This is the new definition of planet in Prague on August 24th, 2006.

& ltbr & gt 1 must be a celestial body orbiting a star.

& ltbr & gt must be large enough in mass, and its own gravity must be balanced with the rotation speed to make it spherical.

& ltbr & gt3 is not affected by other objects around the orbit. Generally speaking, a planet must be more than 800 kilometers in diameter and more than 5 billion tons in mass.

& ltbr & gt But when the mass of the celestial body reaches 1 1 Jupiter, its composition is similar to that of a star, and it is called a brown dwarf.

& ltbr & gt Brown Dwarfs are gaseous objects, similar in composition to stars, but insufficient in mass to ignite the core fusion reaction. Its mass is between stars and planets.