ADS BY GOOGLE
The Galaxy belongs our planet EarthThe concept which we deal then has exclusive and widespread use in the field of astronomy. Because the milky way is a Galaxy, one Galaxy either but not that it is one that is closely linked to our planet Earth since it is the solar system and the planet we all we inhabit.
What are galaxies? Main featuresThe galaxies are groupings of stars and gas, dust, nebulae, planets, among others, and extending throughout the universe.
To galaxies it classifies them is depending on their physical appearance, i.e. depending on the visual morphology it holds. Thus we find elliptical galaxies that already anticipates us its name have a luminous profile such as an ellipse.
On the other hand, are spiral galaxies that have a circular format and structure of curved arms that are shrouded with dust.
Then there are the so-called unusual galaxies because they are the result of disturbances generated by the gravitational attraction of galaxies that are to its around.
And small galaxies do not have a defined structure and many times you include them in the former group.
The milky way a barred spiral galaxyIn the specific case of the milky way is a barred spiral galaxy which has a central stripe of stars very, very bright that covers from side to side the Galaxy. His arms, typical of this kind of Galaxy, arise from the end of bar.
Main physical features of the milky wayThe milky way is the Galaxy in which the solar system and the Earth planet are, its appearance is that of a strip wide white light and diffuse to form crosses obliquely the greater part of the celestial sphere and when you look at it through a telescope, it is discovered that it is composed of an infinite number of stars approximately, calculation says that there are between 200 and 400 billion stars.
The distance that it has with respect to the Sun is 27.700 years light.
On the other hand, the milky way is part of a set of galaxies, some forty approximately, known as the local group, and is the second largest group in terms of brightness and size, after the Andromeda Galaxy.
Origin of its nameThe reason for its name boasts a genuine mythological origin... in latin, Milky concerns milk road and this, imaginative broadly is the appearance that holds this Galaxy and thus Greek mythology recognized it promptly, which argued that Hera, wife of the god Zeus was spilled milk on the breast of the goddess who was refusing to breastfeed her infant son Hercules as consequence that was the fruit of an adventure that had... and the legend was installed, because they say that one day they approached the child to her chest while Hera was asleep, but suddenly this woke up and found the situation, then withdrew it gently from your nipple and thus his deathbed spilled through the skies giving rise to what we now know as milky way.
Although not only through mythology man explained the phenomena at the time, thus Democritus, a well-known astronomer, among the centuries V and IV before Christ, already spoke in terms Milky concentration many star. However they had to pass many, but many years his opinion was valued, meanwhile, would the astronomer Galileo Galilei, who through the use of the telescope would demonstrate that proposed Democritus.
The visual phenomenon that it represents is due to the stars, as mentioned and also to other types of materials that are just above the plane of the Galaxy.
The Galaxy is composed of three parts: halo (shaped structure of sphere that surrounds the Galaxy), disk (made up of young population I stars) and bulb (located right in the Centre and is where there is the highest concentration of stars).
We must also mention that land Galaxy has a number of satellite galaxies, which are characterized by orbiting around it as a result of the action of gravity. The large cloud of Magellan is the largest satellite Galaxy of the milky way. It is the closest to it and is easily visible.
Article contributed by the team of collaborators.