as if Robert Hazen, Ph.D., George Mason University
Edwin Hubble showed that the nebulae are huge, gravitational pulls of stars — perhaps tens, perhaps hundreds of billions of stars. These things are called galaxies. Following Hubble’s discovery, astronomers began exploring fast, deep galaxies, all kinds of galaxies, and this search continues today.
Cepheid variable according to Hubble
American astronomer Edwin Hubble focuses on solving the nebula, an unusual star. From a few hours to several weeks, these are the stars that are fading and fading and shining again. The giant stars that actually started the process of helium burning – about three times the size of the sun.
The star helium starts to burn and the balloon comes out, but when the balloon comes out, it cools down, and the fusion stops and the contract begins again. Then the helium starts to burn again, and then it starts to cool again. So there are times when the star grows bigger and smaller by spending more and less energy on these few hours, a few days or a few weeks cycles.
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Determining distance for different objects
A.D. In 1912, astronomer Henrietta Swan Levitt discovered a striking link between the Cepheid dynamics – the time it takes to turn on and off – and the absolute brightness, how much energy it consumes. Levit was employed as a astronomer at the Harvard Astronomical Observatory. Computers were people who looked at mirror photographs and measured the position of stars.
The bright stars she found have a longer menstrual cycle. Since the absolute brightness of these stars is directly related to their bright and dim time, you can search for dynamic stars from distant objects. You can see how long it takes to become brighter and brighter, you can see what their relative light is for us, and you can determine the absolute distance from these observations.
By measuring time, one knows absolute brilliance; By measuring the relative brightness, one, therefore, knows the distance. It is a clever technique in astronomy and is very important for determining distances for different distant objects.
Learn more about how stars die.
Discovery of galaxies
Using the Mount Wilson Telescope, the celestial variable stars in the M3 galaxy, known as Andromeda, one of the closest and brightest galaxies in the galaxy, have been discovered for the first time.
Edwin Hubble claims to be more than half a million light-years away from Andromeda and Milky Way; And since it was one of the brightest and largest objects in the telescope, other galaxies must be farther away.
Galaxyes come in many sizes and shapes. The most famous are the spiral galaxies, which make up three-quarters of the largest galaxies in the universe. Spiral galaxies are known for their beautiful arms folded into a bright central core.
The Andromeda Galaxy is a typical example of a large, spiral galaxy. It has over 100 billion stars in that spiral.
The spiral galaxies on the surface show a flat disk and a large central swelling. Most of the stars are in the central hemisphere, but there are also many stars in his hands. Our own Milky Way galaxy is a normal spiral, and our home is on one arm, far from the center.
Learn more about the solar system.
Other types of galaxies fall-oval, dwarf, and chaotic
There are many other bright galaxies.
Some of them are very rounded stars with no arms; These are called oval galaxies, and the elliptical galaxies represent one-fifth of the known bright galaxies. They often contain hundreds of billions of stars. Each of these stars may have a system of planets, and each of these planetary systems holds life.
There are also small irregular and tiny galaxies. These are relatively weak, but surprisingly abundant. They still contain billions of stars, are still thousands of light years, and may be the largest galaxy in the universe.
There are relatively few galaxies with distorted shapes; These results are in conflict with two galaxies. When two galaxies meet each other, they are connected by gravity. You may be surprised to learn that even though these galaxies are interconnected, the probability that the two stars will hit each other is insignificant because the stars are so far apart. Thus, two galaxies can interact with gravity without any star collisions.
Common questions about the types of galaxies and their distribution in the universe
The galaxies are billions of stars bound by gravity. They are different. Types Galaxies In the universe, in various shapes and sizes. The most common types of galaxies are spiral and oval galaxies.
Spiral galaxies They have beautiful arms around the central core. They probably make up three-quarters of the galaxies. The Milky Way galaxy is an example of a spiral galaxy.
Oval galaxies Unarmed are a very consistent set of stars. About 20% of the known Types of galaxies They are oval in the universe.