2024年10月22日 · Galaxies consist of stars, planets, and vast clouds of gas and dust, all bound together by gravity. The largest contain trillions of stars and can be more than a million light-years across. The smallest can contain a few thousand stars and span just a few hundred light-years.

A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. [1] [2] The word is derived from the Greek galaxias (γαλαξίας), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System.

2025年1月26日 · galaxy, any of the systems of stars and interstellar matter that make up the universe. Many such assemblages are so enormous that they contain hundreds of billions of stars. Nature has provided an immensely varied array of galaxies, ranging from faint, diffuse dwarf objects to brilliant spiral-shaped giants.

2025年1月14日 · A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity. We live on a planet called Earth that is part of our solar system. But where is our solar system?

2024年5月21日 · What is a galaxy? A galaxy is a vast island of gas, dust and stars in an ocean of space. Typically, galaxies are millions of light-years apart. Galaxies are the building blocks of our...

But galaxies haven’t always been around, and they have changed over the universe’s 13.8 billion-year history. Astronomers study the ways galaxies form and evolve by comparing the different shapes across the history of the cosmos, and tracing how they came to look the way they do.

2025年1月28日 · Astronomers classify galaxies into three major categories: elliptical, spiral and irregular. These galaxies span a wide range of sizes, from dwarf galaxies containing as few as 100 million stars to giant galaxies with more than a trillion stars.

Galactic astronomy is the study of the Milky Way galaxy and all its contents. This is in contrast to extragalactic astronomy, which is the study of everything outside our galaxy, including all other galaxies.

2025年2月4日 · The gargantuan galaxy LEDA 1313424 is rippling with nine star-filled rings after an “arrow” — a far smaller blue dwarf galaxy — shot through its heart. Astronomers using Hubble identified eight visible rings, more than previously detected by any telescope in any galaxy, and confirmed a ninth using data from the W. M. Keck Observatory in ...

Extragalactic Database for Galaxy Evolution (EDGE) The CARMA EDGE survey will provide a measurement of the distribution of molecular gas. in a statistically significant sample of over one hundred galaxies. The survey targets the J = 1-0 transition of CO and its 13CO isotopologue, which trace the bulk of the cold, star-forming gas.