As the nebula collapsed under its own gravity, it spun faster and flattened into a disk. The Sun formed about 4.6 billion years ago in a giant, spinning cloud of gas and dust called the solar nebula. They trace the orbits of planets, whose gravity tugs dust into place around the Sun. Some of that dust is still around today, in several dust rings that circle the Sun. The Sun would have been surrounded by a disk of gas and dust early in its history when the solar system was first forming, about 4.6 billion years ago. MoonsĪs a star, the Sun doesn’t have any moons, but the planets and their moons orbit the Sun. At the equator, the Sun spins around once about every 25 Earth days, but at its poles, the Sun rotates once on its axis every 36 Earth days. Since the Sun is not solid, different parts rotate at different rates. Its spin has a tilt of 7.25 degrees with respect to the plane of the planets’ orbits. The Sun rotates on its axis as it revolves around the galaxy. But even at this speed, it takes about 230 million years for the Sun to make one complete trip around the Milky Way. Our solar system is moving with an average velocity of 450,000 miles per hour (720,000 kilometers per hour). The Sun orbits the center of the Milky Way, bringing with it the planets, asteroids, comets, and other objects in our solar system.
Are x rays from the sun corona quizlet full#
Chicago/Wesleyan/JPL-Caltech | Full caption and image This illustration shows the spiral arms of our Milky Way galaxy. The Sun is located in the Milky Way galaxy in a spiral arm called the Orion Spur that extends outward from the Sagittarius arm. A light-year is the distance light travels in one year, which equals about 6 trillion miles (9.5 trillion kilometers). Its nearest stellar neighbor is the Alpha Centauri triple star system: red dwarf star Proxima Centauri is 4.24 light-years away, and Alpha Centauri A and B – two sunlike stars orbiting each other – are 4.37 light-years away. The Sun is about 93 million miles (150 million kilometers) from Earth. Many stars are much larger – but the Sun is far more massive than our home planet: it would take more than 330,000 Earths to match the mass of the Sun, and it would take 1.3 million Earths to fill the Sun's volume. Our Sun is a medium-sized star with a radius of about 435,000 miles (700,000 kilometers). Yet life on Earth is only possible because of the Sun’s light and energy. The Sun could not harbor life as we know it because of its extreme temperatures and radiation. Helios, the Sun god in ancient Greek mythology, lends his name to many Sun-related terms as well, such as heliosphere and helioseismology. The Latin word for Sun is “sol,” which is the main adjective for all things Sun-related: solar. Since its launch, the mission has kept watch on the Sun. 2, 2020, marked the 25th anniversary of the Solar and Heliospheric Observatory, or SOHO. The corona reaches up to 3.5 million ☏ (2 million ☌) – much, much hotter than the photosphere.ĭec. In one of the Sun’s biggest mysteries, the Sun’s outer atmosphere, the corona, gets hotter the farther it stretches from the surface. The part of the Sun we call its surface – the photosphere – is a relatively cool 10,000 ☏ (5,500 ☌). The hottest part of the Sun is its core, where temperatures top 27 million ☏ (15 million ☌). By studying our Sun, scientists can better understand the workings of distant stars. And many solar systems have more than one star. Stars up to 100 times larger have been found. Its gravity holds the solar system together, keeping everything from the biggest planets to the smallest bits of debris in orbit around it.Įven though the Sun is the center of our solar system and essential to our survival, it’s only an average star in terms of its size. Its diameter is about 865,000 miles (1.4 million kilometers).
The Sun is the largest object in our solar system. The science of studying the Sun and its influence throughout the solar system is called heliophysics.
But the Sun is a dynamic star, constantly changing and sending energy out into space. Without the Sun’s energy, life as we know it could not exist on our home planet.įrom our vantage point on Earth, the Sun may appear like an unchanging source of light and heat in the sky. It’s about 93 million miles (150 million kilometers) from Earth and it’s our solar system’s only star. 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.
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