What is Galaxy in simple words?
A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity.
What defines a galaxy?
Basically, galaxies are the fundamental units of structure in the universe where stars form. Theory currently holds that all galaxies are confined by the gravity of the dark matter halos that permeate and surround them, but there is recent evidence that some galaxies may be dark-matter-free.
What are the 4 types of galaxies?
In 1936, Hubble debuted a way to classify galaxies, grouping them into four main types: spiral galaxies , lenticular galaxies, elliptical galaxies, and irregular galaxies.
Do we live in a galaxy?
We live in a seemingly nondescript neighborhood in the Milky Way galaxy , in a small spiral arm called the Orion Arm. Artist’s concept of our Milky Way galaxy , as seen from far galactic north (the direction of the constellation Coma Berenices) via NASA/ JPL-Caltech/ R.
What is galaxy example?
|Large Magellanic Cloud||0.9||160 kly (50 kpc)|
|Small Magellanic Cloud (NGC 292)||2.7||200 kly (60 kpc)|
|Andromeda Galaxy (M31, NGC 224)||3.4||2.5 Mly (780 kpc)|
What galaxy do we live in?
We live in one of the arms of a large spiral galaxy called the Milky Way .
Why is it called a galaxy?
The word galaxy is derived from the Greek galaxias (γαλαξίας), literally “milky”, a reference to the Milky Way. Many galaxies are thought to have supermassive black holes at their centers. The Milky Way’s central black hole, known as Sagittarius A*, has a mass four million times greater than the Sun.
What is difference between Galaxy and Milky Way?
A galaxy is a system of solar systems and other stars. Galaxies , like solar systems, are held together by gravity. In galaxies , the solar systems are separated by vast sections of mostly empty space. The galaxy that contains the Earth and its solar system is called the Milky Way .
Why is the Galaxy flat?
Solar Systems/ Galaxies are flat because of the rotation of the central mass (star in case of solar system, while a supermassive black hole in case of a galaxy ) around its own axis. Because the sun rotates in a plane, the accretion disc was formed in the same plane, and the resultant planets formed in the same plane.
What is the oldest type of galaxy?
GN-z11 is currently the oldest and most distant known galaxy in the observable universe .
|Distance||≈32 billion ly (9.8 billion pc) (present proper distance) ≈13.4 billion ly (4.1 billion pc) (light-travel distance)|
|Apparent magnitude (V)||25.8H|
How do galaxies die?
Galaxies die when the stars that live in them stop forming. Scientists were able to glimpse a galaxy as it ejected almost half of the gas it uses to form stars.
What is the next nearest galaxy?
The Sagittarius Dwarf Elliptical Galaxy is the next closest , at 662,000,000,000,000,000 km (70,000 light years) from the Sun. The Large Magellanic Cloud , 1,690,000,000,000,000,000 km (179,000 light years) away, was once considered the nearest galaxy outside of the Milky Way .
Is Earth the only planet with life?
Earth is the only planet in the universe known to possess life .
How old is our galaxy?
Where do we live in the universe?
Milky Way Galaxy Our home galaxy, composed of 200 billion to 400 billion stars and filled with the interstellar medium. The Milky Way and those satellite dwarf galaxies gravitationally bound to it.