Gerbangindonesia.org – 12 Names of Galaxies: Definition, Types, and Theory of Their Formation. Basically, the planet Earth that we live in is one of several planets in a solar system. In the solar system, there are not only planets including Earth, but also satellites, meteors, comets, and asteroids, which turns out to be just one of millions of stars belonging to a group of galaxies. Then, that means we live in a galaxy? Yep, that’s right.
In this entire universe, the existence of galaxies is not only one, you know… But there are many galaxies in number, it’s just that our knowledge is still limited and only knows hundreds. Even so, human science up to this moment is already cool, yes, because it is able to know the names of the galaxies that exist!
So what exactly is a galaxy? What are the names of the galaxies in this universe? What is the theory about the process of forming a galaxy, which of course is different from the process of forming the solar system?
What is a Galaxy?
What does Grameds think of when he hears the term “Galaxy?” Do you immediately think of a collection of stars that glow white and form a spiral? If so, Grameds’ thinking is not entirely wrong.
A galaxy is a star system that has a very large size, composed of countless stars. Usually, these stars can also be single stars or star clusters, then there are also planets, clusters, nebulae, asteroids, comets, gas, to cosmic dust. Please note that this planet Earth is not a type of star, because it does not have the ability to emit its own light.
Well, Grameds also must have known that the sun is the center of our solar system. The sun along with the other planets, including the earth, rotates following its orbit or its orbit in a galaxy. This galaxy is known as the Milky Way Galaxy or the Milky Way Galaxy. So it can be concluded that all humans living on planet earth are in the Milky Way Galaxy.
The galaxies that exist throughout the universe consist of billions of stars and celestial bodies, each of which has a variety of types, some of which are red and white stars. The distance from one star to another is very far, so the universe will appear “empty”. However, there are also several tens of thousands of stars that appear to be “close together” around a center, so that when viewed they appear as fog.
Many people can’t tell the difference between a galaxy and a cosmic fog or an ordinary nebula. Well, the following are some of the characteristics of galaxies.
A galaxy that has its own light and the light is not a reflection (fluorescence). In addition, the light will later provide an absorption spectrum indicating that the irradiating object is a solid object surrounded by certain gases.
A galaxy that has a special shape in which there is a luminous core in the center, making it easy to identify.
A galaxy that will be visible outside the path of the Kali Serayu star, no matter how far it is from the sun.
Types of Galaxies
When viewed from its shape, galaxies found throughout the universe can be classified into several types, namely:
1. Spiral Galaxy
This type of galaxy is the most commonly known to people, because most galaxies have this shape. In this type of galaxy, the main parts are called bulges and halos. The bulge is the central part of the galaxy that protrudes and is a solid part. Well, in our galaxy, the Milky Way, the center of the galaxy is in the direction of the constellation Sagittarius, but our eyes cannot see it directly. While hallo is part of the spiral arm.
Generally, spiral galaxies consist of stellar vortexes and the interstellar medium in the form of the center line or the center of the galaxy has stars with very old ages. The stars in this galaxy also consist of young stars and old stars.
Due to its spiral shape, this type of galaxy will rotate at a much greater speed, when compared to elliptical galaxies. Its rotational speed can even cause these galaxies to flatten and form galactic planes. The size of the rotation speed depends on the mass of the galaxy, so not all spiral galaxies have the same rotational speed. Examples of spiral galaxies are M31 (Andromeda), M33 (Triangulum), and M51 (Whirlpool).
2. Elliptical Galaxy (Elliptical)
The shape of this type of galaxy varies, ranging from almost spherical shapes such as ellipsoidal to almost flat. Elliptical galaxies are types of galaxies that are thought to have an ellipsoid shape and look soft, because of the bright light in the interstellar, so almost
The overall shape seems flat and bright. The various shapes in this type of galaxy can of course affect the number of stars in it.
This classification of galaxies was coined by Edwin Hubble in the Hubble classification scheme. Examples of this type of galaxy are M32, M49, and M59.
3. Irregular Galaxy
This type of galaxy is so called because its shape is neither spiral nor elliptical, but a variety of shapes. There are some called Dwarf Galaxy because they are smaller than normal galaxies, for example M110. . Some of the others are called Ring Galaxy because they are shaped like a ring with the center being the center, an example is Object Hong. There is also a so-called Lenticular Galaxy because its shape is a combination of spiral and elliptical types, for example NGC 5866 HG.
Galaxies that do not have this particular shape usually contain interstellar matter consisting of gas and dust, but still have young stars as well as old stars. Another example of this type of galaxy is the Large Magellanic Cloud and the Large Magellanic Cloud, which are located near our galaxy, about 180,000 light years from the Milky Way Galaxy.
Names of Galaxies in the Universe
1. Milky Way Galaxy
This spiral galaxy is where we live with other humans on planet earth. Yep, like other galaxies, the Milky Way Galaxy is of course composed of billions of stars, cosmic fog, dust, and cosmic gases whose distribution is uneven. The collection of stars in this galaxy can even be seen with the naked eye, you know, especially at night. The center of the Milky Way galaxy is a very bright region, shrouded in a debut mist, and usually visible only in radio waves (infrared). Around the center there will be stars and stellar material that stretches to form a plate, with a diameter of about 80,000 light-years.
2. Andromeda Galaxy (M31)
Another galaxy that is equally well known to the general public is the Andromeda Galaxy, because it can be seen directly without binoculars. The Andromeda Galaxy is also similar to ours, in that it is both spiral in shape and the distance between the two is about 2.5 million light years. Another name for the Andromeda Galaxy is Messier 31 (M.31). Messier is the name of a French astronomer who first recorded this galaxy while investigating the existence of galaxies in the universe.
3. Big Magellanic and Small Magellanic galaxies
These two galaxies are located in the southern hemisphere, approximately 150,000 light years from the Milky Way galaxy. These adjacent forms are often considered to be the satellites of our galaxy. The second name, Magellan, is taken from its inventor, namely Ferdinand Magellan, as an astronomer from Portugal.
Since this galaxy often orbits around the Milky Way galaxy, many think that the two galaxies are part of our galactic system, when in fact they are not.
4. The Sombrero Galaxy
The shape of this galaxy is spiral and looks like a sombrero hat, hence the name. Another name for the Sombrero Galaxy is Messier 104 (M104), which is located about 28 million light years from our galaxy. The core of this galaxy is very bright, namely at the center of its large bulge and in the center surrounded by debut.
The massive bulge is thought to be the center of a supermassive black hole, while its dusty path is of great interest to professional astronomers.
5. The Rose Galaxy (Arp 273)
This galaxy is so called because it is shaped like a rose and is located in the constellation Andromeda. Actually, The Rose galaxy consists of 2 galaxies namely UGC 1810 and UGC 1813. At UGC 1810 it is large and has a disk that looks like a rose. Then UGC 1810, which is below UGC 1810, is smaller and even shows different signs of the active star formation process in general.
6. Galaxy Sculptor (NGC 253)
Galaxy NGC 253 is spiral in shape and is said to be the brightest and faintest galaxy. Located in the southern constellation Sculptor at a distance of about 8 million light years. In this Sculptor Galaxy has a lot of dust, even the dust cells are often seen rising from the disk of the galaxy.
7. Black Eye Galaxy (M64)
So called because this galaxy has a dark band that is spectacular in absorbing dust in front of the galaxy’s bright core. The dark band is thought to have formed as a result of a collision with another galaxy. Similar to the Sombrero Galaxy, this galaxy was also discovered by Charles Messier, an astronomer from France.
8. Blue Pinwheel Galaxy
As the name implies, this galaxy has a round shape like a wheel with a blue color. This galaxy is about 2 million light years from our galaxy. Since this galaxy is a close neighbor to the Milky Way galaxy, its members can even be easily seen by humans on earth, either using binoculars or special binoculars.
9. Cartwheel Galaxy
The shape is very unique, similar to the wheels on a lined wagon, and has a distance of about 150,000 light years. This Cartwheel galaxy has a very bright center, with a debut bar and thin gas radiating toward the ring of stars around it.
If from Earth, then the distance is about 500 million light years, which is in the constellation Sculptor. Its unique shape is thought to have occurred due to a direct cosmic collision millions of years ago.
10. The Sunflower Galaxy
The shape looks almost like a sunflower and has another name Messier 63 (M63). Similar to the Sombrero and Black Eye galaxies, this galaxy was also discovered by Charles Messier in 1781. Since its shape is a spiral with many arms, it will look like a sunflower pattern.
If from Earth, then the distance is about 27 million light years, which is in the constellation Canes Venatici. The bright light that often illuminates this galaxy is actually produced by a blue-and-white giant star that formed recently.
11. Ursa Major Galaxy
Another name for this galaxy is the Big Dipper Galaxy. The existence of this galaxy turns out to be very useful for humans on earth, especially sailors who make it a benchmark when sailing tonight. Not only that, the Ursa Mayor Galaxy is also popular among farmers, because in its appearance it is often considered as a marker of the beginning of the time the name of rice, especially in Javanese people who know it by the name Lintang Kartika.
At first glance, this galaxy appears to have a very bright star tip, so of course it can be used as a benchmark when sailing. The number of stars in this galaxy is 6, and it can even be seen in the sky at the North Pole.
12. Whirlpool Galaxy (M51)
The appearance looks like a whirlpool, which occurs due to gravitational disturbances in the universe. If Grameds looked at the stars in the sky using binoculars, he would easily find this galaxy. The Whirlpool Galaxy aka M51 is often an easy target for astronomers in their efforts to study the structure and spiral arms of the galaxy.
Theory of the formation of galaxies
There are two main theories about how a galaxy forms, namely:
1. Chaostic Group Theory
Opinions in this theory were put forward by a group of modern cosmological scholars, who believe that the formation of galaxies is related to the Big Bang Theory in the process of the formation of the universe. If we look back at what the Big Bang theory is, which is the theory that the universe originated from a great explosion that was able to throw all things in all directions. Well, gradually, the thrown objects form a galaxy.
2. Quiescent Group Theory
The opinion in this theory was put forward by a group of cosmologists who believe that the universe actually has a small number of inhomogeneous conditions, so that it will gradually develop to form galaxies.
But until now, no astronomer has a definite theory of how the process of formation of galaxies. Although the two theories of opinion have their respective advantages, it is not concretely certain which theory is true.
Well, that’s a review of the names of galaxies in this universe. Actually, there are still many galaxies scattered throughout the universe, if Grameds is interested in studying it, it can be done by reading astronomy books, right?