Galaxies

A Galaxy is a massive conglomeration of stars and gas that is bound together by the collective gravity of all the objects, It has a center of mass so strong that it can preside over thousands, millions, billions, or even trillions of stars.
Our home galaxy the Milky Way is a barred spiral galaxy, about 100,000 light-years across. If you could look down on it from the top, you would see a central bulge surrounded by four large spiral arms that wrap around it. Spiral galaxies make up about two-third of the galaxies in the universe.

The Milky Way does not sit still, but is constantly rotating. As such, the arms are moving through space. The sun and the solar system travel with them. The solar system travels at an average speed of 515,000 mph (828,000 km/h). Even at this rapid speed, the solar system would take about 230 million years to travel all the way around the Milky Way.

There are different types of galaxies

The Andromeda Galaxy, Messier 31, is the closest spiral galaxy to our Milky Way, around 2.5 million light-years away. It is located in the eponymous constellation Andromeda and is the most distant object that can be observed with the naked eye under good conditions without technical aids. The small galaxy to the left below Andromeda is Messier 110.
The Cocoon Galaxy ARP269 is an interacting galaxy pair with active star formation regions. The two galaxies are connected by a tidal arm. The center of NGC4490 consists of two separate structures - presumably as a result of a collision of two smaller star clusters. The pair of galaxies is surrounded by diffuse star clouds.
The arc-shaped galaxies of the Markarjan Chain with the galaxies Messier 84 and Messier 86 at the top left, the galaxy Messier 87 at the top-middle and the two galaxies Messier 89 and Messier 90 on the right are located in the constellation Virgo.
Messier 81 or Bode's Galaxy and the right galaxy Messier 82 or Cigar Galaxy and lie in the constellation Ursa Major.
The twisting spiral arms of NGC 3169 (left) have been pulled out into sweeping tidal tails by gravitational interaction with the neighboring galaxy NGC 3166. The two galaxies will eventually merge into one.
The Leo Triplet (also known as the M66 Group) is a small group of galaxies about 35 million light-years away in the constellation Leo. This galaxy group consists of the spiral galaxies M65, M66, and NGC 3628.
Pinwheel Galaxy, Messier 101 is a face-on unbarred spiral galaxy in the constellation of Ursa Major, the Great Bear. The galaxy is 21 million light-years away from us.
Hickson 44 is a group of galaxies in the constellation Leo around 80 million light-years away that contains a total of four galaxies with the catalog numbers NGC 3185, 3187, 3190 and 3193.
The Fireworks Galaxy, NGC 6946 is a barred spiral galaxy in the northern sky in the constellation of Cepheus.
The spiral galaxy Messier 106 lies in the constellation Canes Venatici.
The Holmberg 468 galaxy triplet in the constellation Coma Berenices contains the galaxies NGC4725, NGC4712 and NGC4747. The large galaxy NGC 4725 interacts with the neighboring galaxy NGC 4747 at the bottom right of the image and has an extremely massive black hole at its center.
The galaxy cluster "Abell 1367" is located in the constellation Leo and is therefore also known as the "Leo Cluster". Together with the "Coma Cluster" and the "Virgo Cluster" it belongs to the so-called "Coma Supercluster".
The Perseus Galaxy Cluster or Abell 426 is part of the Pisces-Perseus supercluster, which extends over 15 degrees and contains more than 1000 galaxies.
The Triangulum Galaxy, Messier 33 is a spiral galaxy in the constellation Triangle. It is the second brightest spiral galaxy in the northern night sky after the Andromeda galaxy.
Messier 51 (better known as Vortex Galaxy, M51 or NGC 5194) is a famous spiral galaxy in the constellation of Canis Venatici.
The Edge Galaxy NGC891 lies in the constellation Andromeda.
Edge-on-Galaxie NGC 891 and Abell 347 galaxy cluster
The Coma Galaxy Cluster Abell 1656 is a huge collection of over 1000 galaxies in the constellation Coma Berenices. The galaxy cluster has an angular size of about 3° × 5°.
Abell 2151, Hercules Galaxy Cluster, 500 million light-years distant in the constellation Hercules
The Draco Triplet includes the galaxies NGC 5981, NGC 5982 and NGC 5985 in the constellation Draco.
NGC2841 is a spiral galaxy in the constellation Ursa Major in the northern sky.
Galaxy NGC 147 on the left is a dwarf spherical galaxy about 2.58 Mly away in the constellation of Cassiopeia. NGC 147 is a member of the Local Group of galaxies and a satellite galaxy of the Andromeda Galaxy (M31). It forms a physical pair with the near right galaxy NGC 185, another distant satellite of M31.
NGC 7331 is a spiral galaxy in the constellation Pegasus in the northern sky. The object was discovered on September 6, 1784 by the German-British astronomer Wilhelm Herschel.
The spiral galaxy NGC 7331 on the right and the Stephans Quintet glax group on the left lie in the constellation Pegasus.
The UFO galaxy NGC 2683 is a spiral galaxy with an active galactic nucleus in the constellation Lynx in the northern sky.
Top right: Planetary nebulae "Owl Nebula, Messier 97" and Botton left: "Surfboard Galaxy Messier 108"
Astronomic NebulaeStar Clusters and Asterisms