NASA records the death of a star

[Cardinal Pizza Deliverance.]

Wow. Thanks for sharing that, Luna.

[Luna]

Wow. Thanks for sharing that, Luna.

Sure thing!

[Dimocritus]

When a normal star orbits a neutron star at a close enough distance, mass from the normal star can be pulled away from it by the gravity of the super dense neutron star. This mass collects around the companion neutron star and forms an accretion disk. The accretion disk then circles the neutron star, it's mass being slowly pulled towards the surface by gravity. When clumps of mass reach a point close enough to the suface of the neutron star, it goes up in flash fusion, producing a high amount of X ray radiation. Binary systems like this are called X ray binaries.

X ray binaries have been observed before, but only X ray binaries with neutron star companions. But the theory was that, if it could happen with a neutron star, it should also be able to happen with the neutron stars big brother, the black hole.

As far as I know, this is the first observation of an X ray binary with a black hole. What you guys are seeing is NOT the black hole (if you do not know why we can't see a black hole, then maybe you should not be here) or the star it's consuming, but the X ray emmisions of the accretion disk burning up quickly as it approaches the "surface" of the black hole. People have used X rays to detect black holes before, but a black hole in an X ray binary is definitely a really nice catch.

Also, Trip: Twid's right. The front of your jump suit should be blue. Unless you only plan on running away from people. Speaking of redshift, look up gravitational redshifting at the event horizon of a black hole, and compare the view from the reference frame of outside the event horizon to the view from the reference frame of inside the event horizon. Relativity says "oh, yeah? Figure this shit out" when it deals with black holes.

[Mesozoic Mister Nigel]

Dimo, it makes me hot when you're all smart like that.

[Bruno]

Dimocritus, How much damage would something like this do to the rest of the galaxy?

If it were to happen in this galaxy, would it make my nads hurt

or

[Luna]

Dimo, it makes me hot when you're all smart like that.

This.   

[Rumckle]

Dimocritus, How much damage would something like this do to the rest of the galaxy?

If it were to happen in this galaxy, would it make my nads hurt

or

Well, if it were to happen in our galaxy, it would have to be pointed at us to effect us.
But we get hit by x-rays from pulsars in our galaxy, and are still alive, so I think we'd be ok. But Dimo may be able to clarify.

ETA: though I guess if it were blue shifted toward us we may be screwed.

[Dimocritus]

Okay, here's the deal. Let's say that right now, at this moment, the entire mass of the sun was compressed into it's Schwarzschild radius (basically, the size it would have to shrink to, without losing mass, in order for it to be so dense that both electron and neutron degeneracy pressure fail, making it into a black hole).

We won't get "sucked" in. Hell, other than no more sunshine, we would feel nothing.

Gravity is a property of mass, and by turning our sun into a black hole we are only effecting size. Which means the gravitational effects on our solar system would be relatively unchanged, because if our sun, at 1Mo (Mo=Solar Mass) became a black hole, it would still be about 1Mo, dig?

The only place where you would see any significant changes (aside from, like I said, sunlight) would be within the Schwazschild radius, or equivalently, the event horizon (in that case, you wouldn't actually see anything.) which, in the case of the sun, we can figure it out: Rs=2GM/c^2 can be rewritten for objects of 1Mo or larger as: Rs=3xM/Mo km, where M is the mass of the object in solar masses (in our case the sun, 1Mo) and Mo is simply 1 solar mass. Our units are kilometers, and Rs stands for the Schwarzschild radius, or the event horizon. Let's plug in our numbers.

Rs=3x1Mo/1Mo km=3 km (our Mo units cancel, giving us an answer in km)

This means that, if our sun suddenly went black hole, it would have had to shrink down to a radius of 3km (compared to it's original radius: 696,000 km). At that point, gravity wins. The entire mass of the sun would be within it's own Schwarzschild radius, and collapse into a black hole. Just let me clarify, at this point the size of our new black hole would be unknown, because we cannot measure anything within then event horizon. We can only know its Rs, or radius of its event horizon.

Simply put, nothing outside of the 3km Rs would change, aside from sunlight, of course. Our solar system WOULD NOT toilet-bowl flush itself into oblivion, that simply is not the nature of a black hole.

As far as X ray radiation: X ray bursts from a black hole are the result of flash fusion around the "surface" of the black hole. So, the only way we would get bombarded with a super-high level of X rays (there would be an increase in X rays, but) is if the black hole were consuming enough of the right stuff to perform large bursts of fusion, which, like in Luna's link, it would need a companion star to do enough "damage" in the way of X rays. And, I don't have to tell you this, our sun does not have a companion star, therefore the X ray radiation should be "livable."

Again, the only SIGNIFICANT (not negligible) difference would be the sudden lack of sunlight.

[Dimocritus]

Also relevant: EVERY GALAXY HAS A SUPER-MASSIVE BLACK HOLE AT IT'S CENTER. PERIOD. (and that's not to mention all the smaller black holes floating about, but after reading the above, you should realize that it's not THAT scary of a thing)

[Dimocritus]

clarification: The above is just an example. Our sun will never become a black hole, it's too small. It will, instead, become a white dwarf when it eventually goes super-nova.

[Nephew Twiddleton]

Correction. Sol does not have enough mass to supernova. It will swell into a red giant and then shrink into a white dwarf. Meanwhile red dwarves will remain unchanged in that time frame.

[Mesozoic Mister Nigel]

Which is way, way near the top of the list of "things we really don't have to worry about".

[Nephew Twiddleton]

Yep. Earth should be habitable for at least another billion years. A couple of large extinction events will pop up but maybe we'll have spread out into space to have a couple of offshoot decendant species by then.

[Dimocritus]

Correction. Sol does not have enough mass to supernova. It will swell into a red giant and then shrink into a white dwarf. Meanwhile red dwarves will remain unchanged in that time frame.

This is correct. I was actually just fact checking my previous posts from the text book and was going to post a correction.

Your reaction time is impeccable.

[Nephew Twiddleton]

Just caught it at the right time. My bus is late as fuck and now i might have to fight a crowd to get on.