Gravitational waves from a supernova (split from shape of GWs)

[EdEarl]

Would a supernova that makes a neutron star create a spherical gravity wave?

[Robittybob1]

Would a supernova that makes a neutron star create a spherical gravity wave?

We would have to check up on whether supernova produce gravitational waves. If they do it probably is spherical, one spherical wavefront, I'm guessing it won't have a chirp.

Check it out.

[swansont]

Spherically symmetric supernovae don't emit gravitational waves. They need to have some kind of asymmetry so that there's a quadrupole moment.

[Robittybob1]

I wondered where Ed's post went to!

http://cgwp.gravity.psu.edu/events/SrcSimDA/slides/Dimmelmeier.pdf that site seems to predict supernovae will produce a gravitational wave; one peak, a ringdown and a bounce.

Edited March 26, 2016 by Robittybob1

[EdEarl]

ty

[Strange]

We would have to check up on whether supernova produce gravitational waves.

 

In general they are expected to because the collapse is never perfectly symmetrical.

[swansont]

Talk slides leave out detail the audience would be expected to know. But this has come up in other recent threads.

 

The file says it's rotating, so you will have a bulge. That might give you the asymmetry you'd need.

[Strange]

I wondered where Ed's post went to!

http://cgwp.gravity.psu.edu/events/SrcSimDA/slides/Dimmelmeier.pdf that site seems to predict supernovae will produce a gravitational wave; one peak, a ringdown and a bounce.

 

That is very interesting. Apart from the information on the formation of gravity waves, there is a much, much more important lesson for you to learn from that presentation. Can you guess what it is? (I have repeated it rather tediously in some of your other threads on the subject).

[Robittybob1]

 

That is very interesting. Apart from the information on the formation of gravity waves, there is a much, much more important lesson for you to learn from that presentation. Can you guess what it is? (I have repeated it rather tediously in some of your other threads on the subject).

I'm not into guessing. Look it was the first of many articles I could have selected, it wasn't an extensive search. It could be right or wrong but it had the name of a reputable research university.

It was a surprise to me that there would be a ringdown, but I have not had time to look into that , but Swansont mentions spinning as a possible cause.

Edited March 26, 2016 by Robittybob1

[Strange]

I'm not into guessing.

 

What I am referring to is the number of times they highlight the complexity of the problem. So please don't start making wild guesses about the way you think they should behave.

 

 

Look it was the first of many articles I could have selected, it wasn't an extensive search. It could be right or wrong but it had the name of a reputable research university.

 

I don't doubt it is a good source. It has some very interesting information.

[swansont]

Spherically symmetric supernovae don't emit gravitational waves. They need to have some kind of asymmetry so that there's a quadrupole moment.

 

 

 

From the LIGO site

 

http://www.ligo.org/science/GW-Sources.php

 

Consider a star that goes supernova. This explosion will produce gravitational waves if the mass is not ejected in a spherically symmetric way, although the center of mass may be in the same position before and after the explosion.

 

 

Wikipedia

https://en.wikipedia.org/wiki/Gravitational_wave

 

In general terms, gravitational waves are radiated by objects whose motion involves acceleration, provided that the motion is not perfectly spherically symmetric (like an expanding or contracting sphere) or rotationally symmetric (like a spinning disk or sphere).

 

[StringJunky]

 

 

 

From the LIGO site

 

http://www.ligo.org/science/GW-Sources.php

 

 

Wikipedia

https://en.wikipedia.org/wiki/Gravitational_wave

 

There has to be a 'wobble' in the rotation of spherical objects?

[Mordred]

Not necessarily a wobble, if you say have a planet with mountains. (Not perfectly symmetrical) that planet generates gravity waves.

[StringJunky]

Not necessarily a wobble, if you say have a planet with mountains. (Not perfectly symmetrical) that planet generates gravity waves.

OK. Ta.

[DimaMazin]

Not necessarily a wobble, if you say have a planet with mountains. (Not perfectly symmetrical) that planet generates gravity waves.

If even crankshaft creates gravity waves , can it create gravity waves without motion at all?

[Mordred]

No you need motion

[DimaMazin]

No you need motion

Does rotating crankshaft create stronger gravity waves in stronger gravitational field (if speed of rotation and crankshaft mass is the same) ?

Edited March 27, 2016 by DimaMazin

[Mordred]

That's a good question. I would have to answer yes.