A huge mass of stars and planets is called a galaxy.
Mainly in that they have a smaller mass. To be a "star", an object would need to be able to start hydrogen fusion. This requires a certain amount of mass and pressure at the core - which in turn require a certain minimum mass.
Planets and StarsPlanets are comparatively smaller than stars and they don't have their own light, their mass is much lesser, their gravitational force is comparatively weak, etc.
Some examples of objects with a lot of mass include planets, stars, black holes, and large celestial bodies like galaxies.
A brown dwarf.
That's because a planet's gravitational effects on a star are stronger - and therefore easier to detect - if the planet is close to the star, and if it is massive.Current methods of detecting planets usually rely on the gravitational interaction between a planet and a star.
The sun has such a huge mass that it attracts all of the other objects closest to it.
They are all objects held together by gravity. The main DIFFERENCES are the corresponding masses, the fact that planets orbit stars, whereas moons orbit planets, and that stars (due to their greater mass) can convert a lot of energy due to nuclear fusion.
Stars are much bigger than planets. The only stars that are smaller than planets are neutron stars.
All planets have mass.
Yes; wherever in the universe there is mass like planets, stars of even meteors, there is gravity.
Actually, to quite an extent, they do. Whenever enough material in interstellar space accretes together until it has an appreciable mass, and thus attracts even more material to itself, you have the beginning of either a planet or a star. A planet if it is largely solids, or an amount of gas insufficient to make it a star, or a star if it is mostly hydrogen, and has enough of it to cause nuclear fusion at the center.
Stars with a huge mass will consume its fuel faster. in the end it becomes a supernova and soon after (in star-time) it will implode. Depending on its mass, it might become a super-massive black hole or a little dwarf where only one teaspoon of its mass will weigh in at many tons.