Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 20/09/2016 20:01:15
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Dearest Spinologists,
As a sheepy i of course luff to spin round and round and round !!
look, as ewe can from the piccy (which is of course bona fide non doctored true image) I am enjoying spinny luff !!
Now, my spin joyness is enhanced cos I happen to know I was spinning as the fastest thing ever and that's true !!
Someone told me that there are some stars out there that spin like .....well fast also !!......what's that all about ?
...and that there are some things called NeuTRON stars that can spin even faster !!...what a disney inspired star is doing spinning so fast is beyond me !!
i kind of understand why a neutron star would spin so fast because of the resultant supernova of a giant star etc etc...but why would a regular star spin so fast ?
What are the fastest spinning stars and neutron stars ?...and why do some regular stars spin so fast too ?
ewe see, i do not know ....and I'd like to know.....and ewe probably do know...and if ewe share with me then I will also know, which means we will both know and I can then tell other people and they will think i'm klevur !!
hugs and shmishes
mwah mwah mwah !
neil
xxxxxx
Some stars they spin, i mean really fast
If ewe try to hang on ewe would never last
ewe'd need to grip an awful lot
besides indeed they're bloody hot !
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The rate at which a star can spin is limited by its surface gravity. The higher the surface gravity, the faster it can spin without flying apart. So the fastest spinning stars would be white dwarf stars.
Neutron stars are the remains of a star which has experienced a supernova.
A spinning skater pulling in her arms speeds up. Similarly, a collapsing star speeds up.
Some neutron stars emit radio pulses form a point on their surface. We can tell how fast they are rotating by the rate of pulses. The fastest are "milliscenod pulsars", because they rotate in a small number of miliseconds.
It is thought that they could not achieve this speed by the ballerina effect, but rather they increased in speed when gas from a nearby star fell onto the surface, accelerating the rotation.
https://en.wikipedia.org/wiki/Millisecond_pulsar
Black holes attract nearby matter into an accretion disk, which will also spin up a black hole.
The angular momentum affects the shape of the event horizon, and could be measured.
We don't have absolutely positive identification of a black hole, but it may be possible to investigate this by studying rapid variations in X-Rays emitted from the inner edge of the accretion disk, just before the plasma disappears beyond the event horizon: "discoseismology".
https://en.wikipedia.org/wiki/Accretion_disk
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I find the actual spin rate of the Gravity Probe B gyroscopes quoted as approximately 4000 rpm I would expect it to be much higher than that of millisecond pulsars.