will the expansion of the sun occur before andromeda collides with the milkyway?

Question

to alex be:if that is the case the sun will not be around to expand then??

Answer 1

The collision will occur first. But no one will see it. Life on earth would have ended 1-2 Billion years previously. There is a remote possibility that gravitational stresses by passing stars will eject the earth from its orbit and it could exist for the better part of forever as a rogue planet. More likely the planet will be destroyed by the initial red giant expansion of the sun. If it survives that (seriously scorched) it will be destroyed several billion years later in the death throes of the red giant stage as the sun as it collapses into a white dwarf. Nothing in the solar system could survive that event.

Answer 2

Although the Sun is currently expanding a little, the expansion you're talking about (after the sun runs out of hydrogen to fuse to release energy) will not happen for about 5 billion years or so.

Meanwhile, the Milky Way is destined to collide with Andromeda in about 3 billion years. So the collision should precede the Sun expanding by roughly 2 billion years.

But what's that between friends?

Answer 3

Well, our sun is considered to be middle aged - it's been around for about 5 billions years, so presumably has another 5 billion or so to go.

As I understand it, the Milky Way and Andromeda are due to collide (or merge, the jury's out on what will actually happen) in about 3 billion years so that will happen first.

Shame we won't be around to see that - imagine what the night sky will look like with twice the number of stars in it.

Answer 4

No, the galaxies will collide before the Sun expands appreciably, but there is nothing to worry about, because, while the galaxies may collide, the stars within them are so far apart that very few collisions will occur. I read that, of the 500 million stars of both galaxies, about 6 direct collisions will occur.
I like those odds.
The galaxies will have an effect on each other, though, and may form a super galaxy. The milky way itself is a combination of two galaxies, one quite small one draped over one end - the Canis Major Dwarf Galaxy, apparently due to a collision.

Answer 5

light takes millions of years to get from the andromeda galaxie to earth so itll be a while yet. if the sun expands at the same time as the andromeda galaxy starts to collide with the milky way, the sun will kill us as that is much nearer. if the andromeda galaxy collides with the milky way on the far side (away from us) it might not affect us that much and we then might merge into one huge galaxy.
=)

Answer 6

In about 1.2 billion years the sun will have expanded appreciably, but not to what is defined as red giant stage. At that time, the Earth will already be uninhabitable. Any record that a biosphere ever existed will have been eliminated. So by the time of the first merger of the two galaxies, the sun will only be on its way to being a red giant, but its expansion will be well underway.

Answer 7

more than likely yes, but ofcourse thats just my opinion, either way it wont happen for billions of years so dont lose no sleep over it ;-)