Yes, stars can exist outside of a Galaxy, but the majority are within a galaxy.
All stars we currently know of are part of a galaxy. Stars are born within galaxies from clouds of gas and dust. If a star were to exist without belonging to a galaxy, it would likely be a result of very rare and extreme circumstances, such as being ejected from its parent galaxy due to a collision or interaction with another galaxy.
It is less likely for stars in the halo of a galaxy to have planets compared to stars in the disk of the galaxy. This is because the halo contains older stars with fewer heavy elements necessary for planet formation. However, some planets could still exist around halo stars, but they would be rare.
Stars in the middle of galaxies are usually found in the galactic disk, where there is a higher concentration of gas and dust that is conducive for star formation. Stars on the outside of galaxies are often located in the galactic halo, which is a more diffuse region that contains older stars and is further away from the dense center of the galaxy. The distribution of stars within a galaxy is influenced by factors such as gravitational interactions and the history of star formation in that region.
Our sun, also known as Sol, is of average size as stars go. Much larger stars exist in our galaxy, as well as much smaller stars.
Halo stars are older and have lower metallicity compared to disk stars. They often have orbits that take them further away from the plane of the galaxy and they are thought to have formed through different mechanisms, such as mergers with other galaxies or early galactic collapse.
Outside our (Milky Way) galaxy.
All stars we currently know of are part of a galaxy. Stars are born within galaxies from clouds of gas and dust. If a star were to exist without belonging to a galaxy, it would likely be a result of very rare and extreme circumstances, such as being ejected from its parent galaxy due to a collision or interaction with another galaxy.
Yes, we can see stars outside of our galaxy in the night sky. These stars are part of other galaxies that are visible to us from Earth.
We have no knowledge about aliens either within our own galaxy or outside of it. This doesn't mean they don't exist; our galaxy is simply too large, and we haven't explored even the closest stars - at least, not so thoroughly that we can be sure there are no aliens.
Nebulae can exist both within and outside of our galaxy, the Milky Way. Nebulae are vast clouds of dust, gas, and plasma in space where stars can form. They are found in many different galaxies throughout the universe.
We don't know of any planets that aren't within the Milky Way galaxy, but that doesn't mean much; stars that are not in a galaxy are rare, and the nearest such stars are too far away for us to have any hope of finding any planets.
Yes, with the help of powerful telescopes, scientists can observe and study objects outside of our galaxy, such as other galaxies, stars, and nebulae.
No. All the stars you see at night are in our galaxy, but outside of the solar system. The only star in our solar system is the one at its center: the sun.
Halo stars are usually very old stars that do no orbit the centre of the Galaxy the same way that our Sun or other stars in a galaxy. Rather, they travel in elliptical orbits, which often take them well outside the plane of the Galaxy.
Stars, star clusters, distant galaxies, galaxy clusters, nebulae, ...
A galaxy is by a definition a group of stars. If there were no stars it could not be a galaxy.
Every galaxy contains stars, if that's what you mean. "Galaxy" means "big bunch of stars". No stars ===> no galaxy.