Scientists find evidence of 'fossil' galaxy within Milky Way

[Candlelight]

http://www.stuff.co.nz/science/4661883/Kiwi-astronomer-in-orbit-over-find

The shredded remains of a dwarf galaxy buried within our own Milky Way Galaxy have been discovered by a Kiwi scientist.
Astronomer Mary Williams, who is working with an international team in Germany on a million-star survey, found the "Aquarius Stream" with careful searching. "It was right on our doorstep, but we just couldn't see it."
Dr Williams led a team of astronomers using a telescope in Australia, operated by the Australian Astronomical Observatory, to find the galaxy, which had been "gobbled up" by our own, said the observatory's professor, Fred Watson.
Although models predicted that big galaxies such as the Milky Way were surrounded by lots of little ones, Prof Watson said astronomers rarely saw them.
"Perhaps many of them have been eaten up by the big galaxies. So, we're looking at our Milky Way Galaxy to try to find little galaxies that it's swallowed."
Dr Williams said the project team was analysing the movements of 12,000 stars in the Milky Way when she noticed 15 stars moving strangely, at speeds of up to 15,000kmh.
They turned out to be part of a large stream of stars originating from a small galaxy that ours had "dismembered" about 700 million years ago, she said.
As most of the stars in the stream lay in the direction of the constellation of Aquarius, the group had been called the Aquarius Stream.

I love this stuff. Next we'll find space dinosaurs.

 

[TheSeeker]

I for one welcome our new space dinosaur overlords.

 

[Locutus of Bored]

The Milky Way is also in the process of absorbing a few more satellite galaxies right now:

http://en.wikipedia.org/wiki/Sagittarius_Dwarf_Elliptical_Galaxy
http://en.wikipedia.org/wiki/Canis_Major_Dwarf_Galaxy
http://en.wikipedia.org/wiki/Virgo_Stellar_Stream

Top of the food chain.

 

[RJDiogenes]

Actually, I think Andromeda is going to eat us up in about three billion years.

I don't know about you, but I'm going to party like it's 2,999,999,999.

 

[Locutus of Bored]

We're just lulling the Andromedans into a false sense of security before we strike.

 

[Captain_Nick]

 

[Captain_Nick]

Fear not my children. We are protected.

 

[F. King Daniel]

Actually, I think Andromeda is going to eat us up in about three billion years.

I don't know about you, but I'm going to party like it's 2,999,999,999.

I hope you're happy, I 'd at your awful joke.

 

[TorontoTrekker]

Actually, I think Andromeda is going to eat us up in about three billion years.

I don't know about you, but I'm going to party like it's 2,999,999,999.

I hope you're happy, I 'd at your awful joke.

I tried, but it was too much of a strain.

 

[Skywalker]

Actually, I think Andromeda is going to eat us up in about three billion years.

I knew Kevin Sorbo would be the death of us all!

 

[RJDiogenes]

^^ I just hope it's Lexa Doig who consumes me.

Actually, I think Andromeda is going to eat us up in about three billion years.

I don't know about you, but I'm going to party like it's 2,999,999,999.

I hope you're happy, I 'd at your awful joke.

Thank you.

Wait, awful?

I tried, but it was too much of a strain.

Ow.

 

[John O.]

Scientists find a dismembered dwarf galaxy and it's news, my battleaxe of a neighbor finds a dismembered dwarf in a sack outside my apartment and she screams bloody murder.

 

[scottydog]

Actually, I think Andromeda is going to eat us up in about three billion years.

Is Andromeda that much bigger than the Milky Way? Won't it be mutual swallowing?

And if there is life on Earth when Andromeda collides with us, would that life perish?

 

[MetalPants]

​

Actually, I think Andromeda is going to eat us up in about three billion years.

Is Andromeda that much bigger than the Milky Way? Won't it be mutual swallowing?

And if there is life on Earth when Andromeda collides with us, would that life perish?

If I understand it correctly, it would be like trying to shoot a speeding bullet with another bullet. So possibly not likely.

 

[Locutus of Bored]

Won't it be mutual swallowing?

 

[John O.]

Actually, I think Andromeda is going to eat us up in about three billion years.

Is Andromeda that much bigger than the Milky Way? Won't it be mutual swallowing?

And if there is life on Earth when Andromeda collides with us, would that life perish?

No physical collisions are expected to take place, the scales are just too massive. Someone actually asked me this who used to be on this board and I did an off the cuff calculation.

I think the numbers I came up with indicated something along the lines that in order for two star systems to enter "solar system" length scale of each other, from initial distances of thousands of light years apart, they'd have to be on collision courses accurate to the millionth of a second of arc in angular displacement... (one of those astronomical situations that takes the term 'statistical improbability to its infinitesimal limiting case...)

And in fact the time scale of a collision would be on the order of a 100m-1bn years, so stellar and planetary evolution would be a much more dominant time scale with respect to the survivability of life on any potentially "affected" systems.

 

[RJDiogenes]

Actually, I think Andromeda is going to eat us up in about three billion years.

Is Andromeda that much bigger than the Milky Way? Won't it be mutual swallowing?

Andromeda is a bit bigger than Milky Way, but it would be more like... uh, mutual swallowing. Or, actually, more like mutual sloshing back and forth until they merge. Locutus is standing behind me and smiling, isn't he?

And if there is life on Earth when Andromeda collides with us, would that life perish?

Probably not; as has been pointed out, galaxies are still mostly empty space and angular momentum is high. However, it still increases the likelihood of a near encounter, which, even if it happens at high relative speeds would last thousands of millions or years, which could disrupt the Oort Cloud, Kuiper Belt or even the orbits of the planets, with potentially disastrous effects to Earth.

 

[Amaris]

Actually, I think Andromeda is going to eat us up in about three billion years.

Is Andromeda that much bigger than the Milky Way? Won't it be mutual swallowing?

Andromeda is a bit bigger than Milky Way, but it would be more like... uh, mutual swallowing. Or, actually, more like mutual sloshing back and forth until they merge. Locutus is standing behind me and smiling, isn't he?

And if there is life on Earth when Andromeda collides with us, would that life perish?

Probably not; as has been pointed out, galaxies are still mostly empty space and angular momentum is high. However, it still increases the likelihood of a near encounter, which, even if it happens at high relative speeds would last thousands of millions or years, which could disrupt the Oort Cloud, Kuiper Belt or even the orbits of the planets, with potentially disastrous effects to Earth.

Fortunately, I've brought this:

 

[Australis]

Man, that must be some kind of spatula to find that!

 

[ShamelessMcBundy]

I for one welcome our new space dinosaur overlords.

Are they gonna be in F-14s though?