do galaxys rotate? and if so what is at the dead centre?

Answer 1

Indeed some do as stated above, usually due to the accretion forces of a supermassive black hole, like the 200,000 solar mass one at the center of our galaxy, or the 2,000,000 solar mass one at the center of galaxy M87. Surrounding them are dead stars in the form of dwarves, or even some very ancient population II stars.

A few things that were incorrectly stated, are that galactic rotation CAN be measured, but it is immensely slow (we are talking one rotation across maybe a couple hundred million years or so, for small galaxies). Considering that our average-sized milky way is 35,000 light years across, travelling linearly down the center, it would take our sun (going 60,000 km/h) 630,000,000 years to reach the other side. Since it is travelling circularly, it would take something closer to a billion or so years. Likely our solar system has completed about one or two "galactic years," but it is a slow, slow process.

Furthermore, not all galaxies rotate, however. Newer galaxies, such as clusters, have no center point nor supermassive black hole, so they are for the most part stationary in terms of rotation.

The blackhole at the center of our galaxy, as I state above, is closer to 200,000 times the mass of our sun, not the giant underestimation of 1000 times as stated above.

And despite what is says below there isn't a "blackhole at the center of our universe." They are the centroids of galaxies, not the universe. There is no central, universal rotation point as such. Also the explanation below fails to explain why galaxies are denser in their centers - and even then some aren't. Yet the user still complains about other answers' inaccuracies...

Answer 2

Cant beleive the amount of different answers here . .

Our Galaxay is approx 100,000 LY in diameter. It DOES rotate, and takes approx 200 million to make on revolution. This equates to around 60,000mph at our location 26,000 light years from Galactic Central Point. At this central point lies an x-ray source named Sagittarius A*. Astronomers believe here lukes a supermassive black hole weighing in at 2.6million Solar Masses. This enormous mass is confined to an area no larger than the orbit of Earth round the sun - If you where Plutos distance away, you would be able to 'see' the event horizon itself (would look like a black disc they think)

Around this mass, orbit several thousand stars in a very small volume of space. They have some of the fastest motions ever detected - some have been clocked orbiting the mass at 100 miles per second as they hurtle round the source of gravity that is the balck hole. Every so often some gas or some passing dust falls past the event horzon and a burst of x-rays is detected. It is however on a bit of a diet, consuming very little matter at this time in its life. It is not like SF films where whole stars fall into a swirling vortex!! If a star did get to close, it would take several million years for the hole to ingest the stars matter.

Recent study of galaxies of all shapes and sizes, indicated that most, if not all harbour a super-massize black hole at their centres. They also discovered, that the larger the galaxy, the larger the black hole is likely to be. As galaxies merge (as ours will with Andromeda in around 2-3 billion years, the black holes are drawn together by their mutual gravity. Eventually they will merge and the black hole will put on some weight - another 3 million solar masses!!

Astronomers now belive that galaxt formation, and supermassive blackholes are intrinsically linked - in fact some believe they are essential.

Answer 3

Yes, galaxies do indeed rotate. At the centre is a giant, well greased totem pole depicting Nabajuh, the giant squidaphant (much like the Squidataur - an elephant's head on a squid's body - of early Greek mythology) which most scientists credit with the creation of the universe. Without this totem pole the galaxy would be unable to rotate and in all probability it would disintergrate into a mess of tangled tentacles.

Answer 4

Yes galaxies do rotate. the motion need not be around something that is central. They rotate around their own axis - We have both rotational and revolutionary motions. We cannot assume what is at the center of the universe around which all the galaxies revolve. It remains unanswered. Since all galaxies are massive and keep rotating about their own axis they are all either moving away from one another or coming closer. Laws of quantum physics state that if an electron doesnot keep revolving around the nucleus it ultimately continues to spiral downward and falls in to the core (nucleus). Likewise the galaxies must also be revolving around something. Let us say - axis of the universe?

Answer 5

Spiral galaxies, like our own Milky Way, rotate. Many, but not all of them, have supermassive black holes at their centers. These black holes can be millions of times more massive than our sun. Those that do not have black holes at the center tend to be more diffuse, but they still rotate.

However, there are other types of galaxies than just spirals. The elliptical galaxies do not rotate in any coherent fashion. Instead, each individual star is orbiting the center of mass in its own orientation. The probably happens because elliptical galaxies are formed (we think) from the merger of two or more other galaxies, so the rotations are disrupted during the merger. There are often, but again not always, black holes in the centers of elliptical galaxies.

Finally, the irregular galaxies generally do not have any even pattern of rotation either. As their name implies, they are not as uniform as either spiral galaxies or ellipticals. Some, but not all, irregulars have black holes associated with them.

Answer 6

Spiral galaxies (which includes ours) do seem to have a black hollow at or very close to the centre, as evidenced by stellar orbits and delicate curves. in view that elliptical galaxies are considered formed by a collision of spirals (our galaxy and Andromeda are due for purely this type of collision in some billion years), there would should be one there besides. actually, elliptical galaxies seem to have a techniques extra mass than they ought to (again judging by stellar orbits), so probable the black holes contained in the spirals merge into one even as the elliptical galaxy is formed.

Answer 7

They most definitely rotate. The Mayans were the first to discover this, I think, it takes approx 25,765 years to rotate once.
In the centre of the galaxy is a Black Hole.

Answer 8

Some of these answers are mad!

Nigeyboy is nicely put tho. I would add that the rotating galaxy is like a compact disk turning, not water down a sink. This is a phemoneon that is evidence for dark matter, which is mass that we can't yet detect.

Answer 9

i cant believe some of the answers on here.

YES the galaxy rotates. I aint too sharp at physics but what i sorta know is :

there is a super massive black hole at the centre of our universe. It doesn't effect us because we are too far from it but it does have a massive gravitation force which keeps everythin around it in orbit.

or a logical explanation is that all galaxies are denser towards the centre compared to outer bits of it. That is there are more stars at the centre. The galaxy rotates around them.

Answer 10

Yes they do rotate (well spirals do in elliptical galaxies it's a bit more complicated). We thinks that most galaxies have a super massive black holes in their centres.