Our milky route is one of the over 100 galaxies tied together by gravity.
The depiction of this artist reflects some main members of the local group of galaxies, with Milky Way. Credit: Astronomy: Roen Kelly
- Edwin Hubble initially identified around 11–12 galaxies within the local group, a term that he coined, while current estimates place members at 125 or more.
- The total mass of the local group, about 2 trillion solar mass, is mainly concentrated in its two largest galaxies, Milky Way and Andromeda, each of which has about 1 trillion solar mass.
- The diameter of the local group is estimated to be around 10 million light-year, cluster around the Milky Way and Andromeda with members galaxies.
- Many galaxies within the local group including NGC 147, NGC 185, NGC 205, M33, M31, and others are observable by amateur astronomers in optimal conditions, using medium -sized telescopes.
American astronomer Edwin Hubble (after which Hubble Space Telescope) coined the word “local group” for galaxies that he recognized as he proceeded through space with Milky Way. The word appeared in his 1936 book, Scope of nebulaHe identified 11 certain members with 12th. Today, astronomers have shown that the local group has 125 members with several dozen others still ready for possible inclusion.
One of the most strange things about the local group is that it contains a combined mass of 2 trillion flax in all galaxies. Two largest members, however – Milky Way and Andromeda Galaxy – each has a mass of about 1 trillion flax. This means that 123 (or more) small members contribute little to the overall mass of the group. This makes sense because most of the galaxies in the local group are dwarfs, some of which are slightly larger than only star groups.
Although most of the members gather around Milky Way or Andromeda Galaxy, astronomers believe that the local group has a diameter of about 10 million light-year.
Observe some of them
Most galaxies in the local group are far from the reach of amateur telescopes. But can be seen by several dozen observers. Here is a list of Ujjwal as compared to the magnitude 10 in the order of their correct heaven. Any medium -sized binoculars should reveal some details at a dark, clear night. In the list, the name is first // then magnitude // then the size.
NGC 147 // 9.5 // 13 ′ 8 ′
NGC 185 // 9.2 // 12 ′ 10 ′
NGC 205 // 8.1 // 22 ′ 11 ′
M32 // 8.1 // 8′.7 6 The.5
Andromeda Galaxy (M31) // 3.4 // 190 ′ 60 ′
Small Magalanic cloud // up to 2.3 // 320 ′ 185 ′
Sculptor Galaxy (NGC 253) // 9.0 // 40 ′ 31 ′
IC 1613 // 9.2 // 16 ′ 15 ′
Thepinwheel Galaxy (M33) // 5.7 // 71 ′ 42 ′
Fornax dwarf spherical // 9.0 // 17 ′ 13 ′
Big Magalanic Cloud // 0.6 // 645 ′ 550 ′
NGC 6822 // 9.0 // 16 ′ 14 ′
You get success!
