List of galaxies - Wikipedia
There are about 51 galaxies in the Local Group (see list of nearest galaxies for a complete list), on the order of 100,000 in the Local Supercluster, and an estimated 100 billion in all of the observable universe. [1] The discovery of the nature of galaxies as distinct from other nebulae (interstellar clouds) was made in the 1920s.
Galaxy Types - Science@NASA
Scientists sometimes categorize galaxies based on their shapes and physical features. Other classifications organize galaxies by the activity in their central regions – powered by a supersized black hole – and the angle at which we view them.
Galaxies - NASA Science
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.
Types of Galaxies | Pictures, Facts, and Information - AstroBackyard
There are four distinct types of galaxies in the universe, elliptical, spiral, barred spiral, and irregular. Although these are the four main types, there are various types of galaxies and the way in which they are classified is by their shape. A galaxy is a cluster of stars, gas, and dust that are kept together by the force of gravity. Within ...
Galaxies - HubbleSite
2024年10月28日 · What Kinds of Galaxies Are There? 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 …
Lists of galaxies - Wikipedia
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek galaxias, literally 'milky', a reference to the Milky Way galaxy that contains the Solar System.
Types of Galaxies | NASA Space Place – NASA Science for Kids
2022年1月19日 · A galaxy is a huge collection of gas, dust, and billions of stars all held together by gravity. All galaxies are made up of these same things. However, they come in many different shapes and sizes. Here are a few types of galaxies: Spiral galaxies look like giant pinwheels. The arms of the pinwheel are made up of stars and lots of gas and dust.
Galaxies—facts and information - National Geographic
2019年4月17日 · Some galaxies are similar to the Milky Way, but some are quite different. Galaxies are sprawling systems of dust, gas, dark matter, and anywhere from a million to a trillion stars that are held...
Galaxy - Elliptical, Spiral, Irregular | Britannica
2024年12月21日 · In Hubble’s scheme, which is based on the optical appearance of galaxy images on photographic plates, galaxies are divided into three general classes: ellipticals, spirals, and irregulars. Hubble subdivided these three classes into finer groups.
What are the different types of galaxies in the universe?
2022年9月20日 · Hubble created the Hubble Sequence classification system in 1926, which tends to be used by both professional and amateur astronomers today. This tuning fork diagram shows the types of galaxies: Elliptical, Lenticular, and Spiral. A fourth class, the Irregular Galaxies, was added to include all the galaxies that didn’t fit those requirements.