5 galaxies in the observable universe

The Galaxy is a system that is bound by the gravitational force which consists of stars, gas and dust of the interstellar medium, as well as cosmic dark matter. There are probably more than 100 billion (1011) galaxies in the universe that can be observed. Most galaxies are 1,000 to 100,000 parsecs in diameter and are usually separated by distances calculated in millions of parsecs (or megaparsecs). The following 5 of which galaxies, including galaxies where we take shelter inside.

 

1. Milky Way Galaxy

 

The milky way (Milky Way or Via Lactea), is a large spiral galaxy with a total time of approximately 1012 solar masses, which have 200-400 billion stars 100,000 light years in diameter and thickness of 1000 light years.The distance between the Sun and the Galactic Center estimated 27,700 light-years. In the Milky Way Galaxy is the solar system, which is the planet Earth where we live. Allegedly at the center of galaxies resides suggests that supermassive black hole called Sagittarius a. our solar system takes 225 – 250 million years to complete one orbit, so it has 20 – 25 times around the Galactic Centre than ever since the formation. The orbital speed of the solar system is 217 km/s.

Stellar disk of the milky way about 100,000 light years in diameter (9.5 × 1017 km), and is expected to have an average thickness of 1000 light years (9.6 × 1015 km). The milky way diestimasikan has at least 200-400 billion stars. Beyond the stars, is a disc of disc of gas which is thicker. The last observation indicated that the gas disc of the milky way has a thickness of about 12,000 light years (1.1 × 1017 km) – amounting to twice the value that was received earlier.

2. the Andromeda Galaxy

 

Other name Messier 31, M31, or NGC 224 is one of galaxies outside the Milky Way galaxy that can be seen with the naked eye, as long as the views on a clear night, without months and without light pollution. Its structure is similar to the Milky Way Galaxy is spiral-shaped. The distance is about 2.5 million light years away. Its location in the sky is in the northern sky, about 41 degrees north of the equator, both observed the sky around September, October, November. To the naked eye, it looks like a thin fog in the northern sky, but if observed with binoculars that can appear dimmed on the stars-star Andromeda Galaxy, Andromeda size turned out to be more than 7 times a month. diamter This Galaxy contains roughly 1 trillion stars, and move closer to the milky way with a speed of about 1000 km/s.

3. Bode's Galaxy

 

Bode's Galaxy (Messier 82 or NGC 3031) is a spiral galaxy located about 12 million light-years away in the constellation of Ursa Major. Messier 81 has been studied extensively by professional astronomers. The size of the Galaxy and relatively high brightness makes the popular target for amateur astronomers. Messier 81 was first discovered by Johann Elert Bode in 1774. Consequently, the Galaxy is sometimes referred to as "Bode's Galaxy". In 1779, Pierre Messier and Charles Mechain identifies the object again, later Bode listed in the Messier Catalogue.

4. the Cartwheel Galaxy

 

Cartwheel Galaxy (ESO 350-40) is a lenticular Galaxy about 500 million light-years away in the constellation Sculptor. The mass of the Galaxy is estimated at 2.9-4.8 × 109 solar masses, and rotates with a speed of 220 km/s. discovered by Fritz Zwicky in 1941. When found, Zwicky considers Cartwheel as one of the most complicated structure based on the dynamics of stars. Its size is slightly larger than the milky way.

5. Messier 82

 

Mesier 82 (NGC 3036, Cigar Galaxy or M82) is the prototype nearby Starburst Galaxy, located about 12 million light-years away in the constellation of Ursa Major. Starburst Galaxy five times brighter than the Milky Way Galaxy, and a hundred times more light to the center of our galaxy. In 2005, the Hubble Space Telescope revealed there are at least 197 young massive clusters in Starburst core. The average mass of the cluster is approximately 2 × 107 m⊙, hence it is not surprising if the core is a very environment Starburst energetic and high-density. All galaksinya Center, young stars are being born 10 times faster than those who are in the Milky Way Galaxy. (**)