Besides the sun, what is the nearest star to the earth?

Besides the sun, the nearest star to the earth is proxima centauri.

Proxima centauri is located in Centauri, about 4.22 light-years away from the Earth (equivalent to 39,923.3 billion kilometers), and it is the closest star to the solar system found at present. Unlike a single star like the sun, there are two stars near proxima centauri, which form a "three-star system" with proxima centauri. The proxima centauri is dim from the earth, and it was not until 19 15 that Robert innis, then director of the Johannesburg Joint Observatory, discovered it in South Africa.

Previously, astronomers have discovered a planet B (neighboring star B) around proxima centauri, whose mass is 1.3 times that of the Earth and that of period of revolution is 1 1.2 days, and speculated that there may be another proxima centauri C (proxima centauri C) with an orbital period of more than 200 days. These planets may be in livable areas, which has aroused strong concern in the international astronomical community.

Extended data

Spatial environment of proxima b

Proxima b is only 7 million kilometers away from proxima centauri, only 5% of the distance between the sun and the earth. Even Mercury, the innermost ring of the solar system, is more than eight times as far away from the sun.

Because proxima centauri is a red dwarf, its mass is only 0. 123 times that of the sun, its luminosity is only 1.55‰ of that of the sun, and its surface temperature is about 2500 degrees Celsius, which is less than half of that of the sun. This makes the neighboring star B still in the livable zone.

Since 20 16, the 3.6m HARPS spectrometer at La Silla Observatory in Chile has been observing proxima centauri carefully. According to the latest data of the "Dim Red Dot" project, proxima centauri sometimes approaches the Earth at a speed of 5 kilometers per hour, and sometimes leaves the Earth at the same speed.

Astronomers have calculated that the repetition period of radial velocity is 1 1.2 days. Further analysis shows that the reason for this result may be the existence of a planet whose mass is about 0/.27 times that of the Earth. Nearby star B has just given away the clues.

In the study of livability and climate of neighboring star B, the research team found that the star may have liquid water under certain conditions. In the most sunny areas, liquid water can even exist on the earth's surface, for example, in the case of synchronous rotation (like the moon) towards the hemisphere of the star, or in the so-called tropical areas with 3: 2 * * * vibration mode (like Mercury).

People's Daily Online-China Scholars Reveal the Orbital Characteristics of proxima centauri System

People's Daily Online-Expert Interpretation of Proxima B: There are no four seasons, and the space environment is bad

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