The Sun is a 4.5 billion-year-old yellow dwarf star – a hot glowing ball of hydrogen and helium – at the center of our solar system. It’s about 93 million miles (150 million kilometers) from Earth and it’s our solar system’s only star.

2025年1月9日 · The Sun is the star at the heart of our solar system. Its gravity holds the solar system together, keeping everything – from the biggest planets to the smallest bits of debris – in its orbit.

The star nearest to the planet Earth is the sun. The sun’s diameter is 1.4 million kilometers and its distance from Earth is 150 million kilometers. But what do numbers that big really mean? To get an idea of size, use a grapefruit to represent the sun. Set it down and walk a dozen steps away. Turn around and

the giant stars, with eight solar masses (that is, having eight times the mass of our sun) have luminosities, or brightnesses, about 1000 times that of our sun. More massive stars use up their fuel even more quickly: a 40 solar mass star can be 50,000 times as bright as our sun! A …

2000年6月7日 · The Stardust spacecraft is 3-axis stabilized in all mission phases, following separation from the launch vehicle. The primary attitude determination is via the star camera and the inertial measurement unit (IMU), and is backed up by analog sun sensors.

A neutron star is one example of a stellar remnant: something left behind by a star at the end of its lifetime. Stars are what they are because they burn hydrogen gas.

2017年6月12日 · The sun is a star and a star doesn't have a solid surface. Rather, it's a ball of ionized gas 92.1% hydrogen (H2) and 7.8% helium (He) held together by its own gravity. NASA's Solar Dynamic Observatory keeps a steady watch on the sun.

2018年2月9日 · The star tracker, which also has a backup on board, uses a camera to image the sky and pattern-recognition software to discern which bright stars are in the field of view. This allows the system to identify the spacecraft's orientation at that moment.

Despite the fact that our sun has a mass of 2x1030 kg (or nearly a million times the mass of the Earth), and a radius of 7x10 5 km (about 100 times greater than the radius of the Earth), it is a typical, average-sized star.

2019年3月12日 · At some distance from the Sun, according to a decades-old prediction, the star’s mighty heat should vaporize dust, sweeping clean an entire stretch of space. Knowing where this boundary is can tell scientists about the composition of the dust itself, and hint at how planets formed in the young solar system.