do galaxies grow?

Question

lets start at a simple concept. gallaxy A has 500 stars. when the stars die, does their mass leave that galaxy? Is it possible for galaxy A to shrink to 400 stars? can galaxies grow? when 2 galaxies come together, do they combine into one or pass through and create a 3rd one?

Answer 1

Yes and NO! when galaxies collide, results vary and the outcome is unpredictable. some galaxies grow and some lose stars. Another outcome is a third galaxy forms and takes some stars and mass with it. the directions of them also change. just think of it this way. three boys each throw a snowball at the center of an imaginary spot. the balls all collide at every swing and attempt. the results will vary each time depending on the speeds, mass, distance and other factors that i haven't thought of. go and throw a mudball at a pole. record the results. imagine the results of three balls hitting at the pole. then imagine the same without a pole. then in a vacuum in space.

Answer 2

Yes, in fact galaxies wouldn't exist if they hadn't grown to the point they're at now already. The mass of the stars doesn't necessarily leave the galaxy, but still orbits around the center as planetary nebulae, supernova remnants or whatever is left after it dies. The actual number of stars will fluctuate, shrinking or growing as stars die or are born in stellar nursery nebulae, but the total mass in a galaxy will stay the same unless it passes near or collides with another. If that happens, it depends how fast they're going relative to each other, how big each one is and the angle at which they "hit" (since galaxies are made of stars which are lightyears away from each other, there is very little if any actual impacting). They might combine to form a single galaxy, or pass through and remain two galaxies, or I'm sure there are dozens of other possibilities.

Answer 3

When a star dies, it either explodes and becomes a supernova, spreading gases and dust into space, or it shrinks and becomes a ball of iron. Either way, the mass + energy in the galaxy remains constant. Though it may expand and contract through its lifespan, the mass will not change. If two galaxies collided, it would depend on the mass and trajectory as to the outcome. It could become one large galaxy when the smaller of the two is pulled into the gravity of the first, or it could break into multiple galaxies.

Answer 4

yes gallaxies are constantly growing. think of a galaxy as the shrapnel for an explosion. the shrapnel expands from the point of explosion so the gallaxy is constantly growing in spacial size...but not as far as matter is concerned. matter cannot be created nor destroyed...merely transferred. if a star dies...it still has mass...if it exploads....it's mass stays the same...it mearly breaks apart and spreasd its self out...kinda like a box of cerial. the box has a mass of cherioes in it......putting a firecracker in the box and blowing it up doesn't make the cherioes dissapear...it spreads them out all over the place. 2 gallaxies which begin to pass into eachother as they expand do not create a 3rd gallaxy they merge the 2 together....if two puddles of water spill into eachother....they don't create an equal 3rd puddle, they merge together making one larger puddle...same applies

Answer 5

Galaxies are very dynamic entities! They can grow by accumulating matter, from outside of the galaxy. They can form new stars from their dust and gases, and the remnants of old stars. They can fling stars, dust and energy out, larger galaxies can "swallow" smaller ones, and galaxies can collide and become one or rip eachother apart in passing. This is why there are so many different types of galaxies!

It's thought that one of the ways large numbers of stars form in galaxies is by gravitational waves (yet to be confirmed). It's thought these waves help to create the dense sprial arms of a galaxy, in which dust and gases are being swept up and condensed into stars. Stars also form in nebulas such as the orion nebula.

Sometimes stars pass near a massive object, which, if it doesn't destroy them, flings them out of the galaxy at amazing speeds. These stars can live out the rest of their life in intergalactic space or even be captured by other galaxies if one is close enough.

So, yes to your question.

Answer 6

The mass of the Universe is constant however the mass of certain parts of it moves so some mass of a galaxy could 'wander' to other galaxies. Also when galaxies collide parts could merge and other parts leave depending on the gravities involved you could get one supergalaxy or any number of smaller one.

Answer 7

It is hard to answer because too many scientists tried to find the answer. But one thing for sure You can find the answer in your self. Think about your body as a one galaxy with billions stars and worlds. your galaxy did not existed till one galaxy meed an other and sent one star in to it to create you and then your galaxy came out and it will grow till you reach your pick and then it will collapse and die but it wont disappear at ones it will return back to one big original point (in our case earth) to be dismantle in to billions pisses to start from beginning.

Answer 8

Galaxies can shrink, grow, mix, mold, or disappear altogether. It all depends on the lifetimes of stars, and what happens to the stars (if they turn into dwarves or implode into blackholes). Regardless, galaxies usually get smaller once the majority of the stars start to die rapidly.

Answer 9

the number of stars in a galaxy is always changing and they have billions of stars not 400

Answer 10

I don't think galaxies pass through each other for one, I mean, could you imagine...?? As far as growth of galaxies, well, I'm no expert, but I'd say that they do. If the "big Bang" theory were correct, we would have to assume that they do, right?