Question conserning Neutron stars

[reyam200]

What would happen if two neutron stars collided? what effect would that have on the surrounding space? if i remember correctly, neutron stars are extremely dense, so two colliding would probably cause a shock wave of some sort.

assuming they collide at high speed.

 

Also, Don't neutron stars usually collapse into a black hole?

[Spyman]

The collision of two neutron stars would result in a GRB and most likely create a black hole.

 

Gamma-ray bursts (GRBs) are the most luminous events known in the universe since the Big Bang.

 

a specific subclass of GRBs (the "short" bursts) appears to be due to another process, possibly the collision of two neutron stars orbiting in a binary

 

http://en.wikipedia.org/wiki/Gamma_ray_burst

 

 

The most intense explosions in the universe come in two varieties. One type lasts several seconds, and the others are gone in less than a second.

 

New observations show convincingly that they are created by collisions of two very dense objects, likely neutron stars or a neutron star and a black hole, as theory had predicted.

 

http://www.space.com/scienceastronomy/051005_short_bursts.html

[reyam200]

That makes since, because of the creation of a black hole any matter that survived the collision and got thrown off would probably be pulled back.

 

that would definitely be interesting to observe first hand.

[[Tycho?]]

Interesting yes, dangerous as well.

[swansont]

That makes since, because of the creation of a black hole any matter that survived the collision and got thrown off would probably be pulled back.

 

that would definitely be interesting to observe first hand.

 

The gravity of the black hole wouldn't be any larger than that of a regular star of the same mass. Any matter thrown off would probably continue to leave.

[reyam200]

The gravity of the black hole wouldn't be any larger than that of a regular star of the same mass. Any matter thrown off would probably continue to leave.

 

so, would it be similar to a SME? (i think thats what their called.) if so, how would such a phenomena effect earth? if it was just outside the solar system.

 

;318661'']Interesting yes, dangerous as well.

 

yes, thats the fun part.

[Spyman]

so, would it be similar to a SME? (i think thats what their called.) if so, how would such a phenomena effect earth? if it was just outside the solar system.

A CME outside of the solar system would likely effect Earth in a much lesser extent than when it happens within the solar system due to the large distances involved.

 

A coronal mass ejection (CME) is an ejection of material from the solar corona, observed with a white-light coronagraph.

 

The material consists of plasma consisting primarily of electrons and protons (in addition to small quantities of heavier elements such as helium, oxygen, and iron), plus the entrained coronal magnetic field. When the solar cloud reaches the Earth as an ICME (Interplanetary CME), it may disrupt the Earth's magnetosphere, compressing it on the dayside and extending the nightside tail. When the magnetosphere reconnects on the nightside, it creates trillions of watts of power which is directed back towards the Earth's upper atmosphere. This process can cause particularly strong aurora also known as the Northern Lights (in the Northern Hemisphere) and the Southern Lights (in the Southern Hemisphere). CME events, along with solar flares, can disrupt radio transmissions, cause power outages (blackouts), and cause damage to satellites and electrical transmission lines.

 

http://en.wikipedia.org/wiki/Coronal_mass_ejection

[Norman Albers]

Also, Don't neutron stars usually collapse into a black hole?

 

There is certain range of stable masses for neutron stars. I am not sure of latest exact numbers, but the Chandrasekar limit describes the maximum mass of a white dwarf, something like 1.3 solar masses. Similarly, neutron stars may exist up to just under 2 masses; so depending on how much mass is thrown off in the collision, two n-stars could become a BH. I HAVE A QUESTION: Do neutron stars have to be hot except for accretion (which could be matter and radiation)? Are they not devoid of nuclear fusion and thus internal heat production? A parallel question asks if we can speak of temperature in a nucleus. An "ideal gas" can be arbitrarily compressed and thermal energy taken out. It's not clear to me that this concept can be extended.

[Spyman]

I HAVE A QUESTION: Do neutron stars have to be hot except for accretion (which could be matter and radiation)? Are they not devoid of nuclear fusion and thus internal heat production? A parallel question asks if we can speak of temperature in a nucleus. An "ideal gas" can be arbitrarily compressed and thermal energy taken out. It's not clear to me that this concept can be extended.

While "the exact nature of the superdense matter in the core is still not well understood", I think they are predicted to cool gradually to become denser than Black dwarfs similar to White dwarfs timeline. But there is also models of Quark stars and mixed models with neutron shells and quark cores.

 

This core has no further source of energy, and so will gradually radiate away its energy and cool down.

Eventually, over hundreds of billions of years, white dwarfs will cool to temperatures at which they are no longer visible. However, over the universe's lifetime to the present (about 13.7 billion years) even the oldest white dwarfs still radiate at temperatures of a few thousand kelvins.

http://en.wikipedia.org/wiki/White_dwarfs

 

A quark star or strange star is a hypothetical type of star composed of quark matter, or strange matter. These are ultra-dense phases of degenerate matter theorized to form inside particularly massive neutron stars.

It is theorized that when the neutron-degenerate matter which makes up a neutron star is put under sufficient pressure due to the star's gravity, the individual neutrons break down into their constituent quarks, up quarks and down quarks. Some of these quarks may then become strange quarks and form strange matter. The star then becomes known as a "quark star" or "strange star", similar to a single gigantic hadron (but bound by gravity rather than the color force). Quark matter/strange matter is one candidate for the theoretical dark matter that is a feature of several cosmological theories.

http://en.wikipedia.org/wiki/Quark_star

 

A neutron star has some of the properties of an atomic nucleus, including density, and being made of nucleons. In popular scientific writing, neutron stars are therefore sometimes described as giant nuclei. However, in other respects, neutron stars and atomic nuclei are quite different. In particular, a nucleus is held together by the strong force, while a neutron star is held together by gravity. It is generally more useful to consider such objects as stars.

http://en.wikipedia.org/wiki/Neutron_star

[Norman Albers]

Beautiful, helpful answers! I am linking event horizons to collapse of two spatial dimensions. Could the quark star be seen as being partway there, namely collapse of one dimension? Logically this could only be the radial one, since it's hard to see choosing a preferred direction, or polarization between the two available transverse dimensions.

[Norman Albers]

I describe the Schwarzschild solution as implying absorption of light in the interior of a black hole (BH). This comes directly from looking at the metric terms distinctly in the radial and transverse cases. The square of c in the transverse sense is negative. This transverse propagation depends on the population of radial vacuum dipoles. Obversely, on the outside, to have a "one-dimensional collapse" we need to see change in the population which supports radial propagation. Thus we would seek physics of the transverse dipole populations in this case, as a possibility for quark stars. Can anyone help relate this to quark physics?

[Norman Albers]

I guess a 1-D collapse would require a different metric, or at least a minus sign on the g_11 term. I'll try to see if this makes any sense from this perspective.