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Sirius B

Adapted from Wikipedia · Explorer experience

An artist's impression of the Sirius binary star system, showing the bright star Sirius A and its tiny companion Sirius B, along with familiar constellations in the background.

Sirius B is a special kind of star called a white dwarf. It is the quiet friend of Sirius A, the brightest star we can see at night. Together, they are in a group of stars called Canis Major, which means the “Greater Dog”.

Sirius B is very heavy but very small. It is about the size of Earth but holds as much weight as the Sun. Long ago, Sirius B was a big star, but now it has used up all its energy and cannot shine brightly like before.

Even though Sirius B is part of the closest star system to Earth, we cannot see it without a telescope. This is because it is much dimmer than Sirius A. The whole system is about 8.6 light-years away from us, making it the fifth-nearest star system to the Sun.

Scientists have looked closely at Sirius B but have not found any extrasolar planets around it. Sirius B is one of the most interesting stars for astronomers to study because of its unique size and weight.

Images

An artist's drawing comparing the size of the tiny but super-dense star Sirius B to our Earth.
A diagram showing how stars with masses between 0.8 and 8 times that of the Sun evolve over time.
A stunning view of Earth rising over the Moon, captured by astronauts on the Apollo 8 mission in 1968.
An artist's impression of HE 1523-0901, one of the oldest stars in our galaxy, located about 7,500 light-years from Earth.

This article is a child-friendly adaptation of the Wikipedia article on Sirius B, available under CC BY-SA 4.0.

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