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/sci/ - Science & Math

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6735280 No.6735280 [Reply] [Original]

We know that a star can become large enough to have a gravitational pull that draws in even the light that it emits. Is it possible for there to be a star closer to our solar system than Alpha Centauri, we just can't see it? Would we feel the gravitational effect of a star that large? Would it also absorb the light of objects behind it as well?

>> No.6735332

>>6735280
Are you asking if there are black holes between us and Alpha Centauri? I think its fairly unlikely as they usually are somewhat apparent because they tend to act on their surroundings pretty strongly. I'm not sure though, if it was isolated enough there might be.

>> No.6735336

>>6735280
i dont know but im interrested

>> No.6735341

>>6735332
Not a black hole, just a star large enough to absorb all of the light that it emits.

>> No.6735353

>>6735341
No such object exists as you have just defined it. The only way an object could be massive enough to have a gravitational effect on light is if it were a blackhole.

>> No.6735356

>>6735353
Actually I take that back, as certain stars are capable of causing a phenomenon known as gravitational lensing, but even these stars aren't "absorbing" the light they emit, so, once again, no "star" exists as you have defined it.

>> No.6735362

>>6735341
You are describing a black hole. Some of the most massive stars can cause whats called gravitational red shift where the light they emit is somewhat red shifted due to their gravitational field. Anything that is so massive that its escape velocity is greater than C is a black hole.

>> No.6735365

>>6735356
http://en.wikipedia.org/wiki/Dark_star_(Newtonian_mechanics)

>> No.6735385

>>6735365
this is ooooooooooooolllllld shit im pretty sure. These are just called black holes now adays

>> No.6736809

What about something that is very close, but not quite a black hole.

????????

>> No.6736860

>>6736809
A neutron star?

Quark gluon star?

But none prevents light from escaping.

Both stars are greater the schwarzchild radius of their masses.

>> No.6737426
File: 1.82 MB, 225x180, 225px-Black_hole_lensing_web[1].gif [View same] [iqdb] [saucenao] [google]
6737426

if it pulls it bends 2

>> No.6737540

>>6735280
>We know that a star can become large enough to have a gravitational pull that draws in even the light that it emits.
Those are black holes, not normal stars. I don't think a star emits light after it collapses to a black hole.
> Is it possible for there to be a star closer to our solar system than Alpha Centauri, we just can't see it?
No, we'd have detected it's gravity and how it would have interacted gravitationally with Sol and other nearby stars.
> Would we feel the gravitational effect of a star that large?
Yes.
>Would it also absorb the light of objects behind it as well?
yes, they're opaque, although I believe black holes can also generate gravitational lensing, in which case the light from stars behind the BH would be bent around the BH, you would still see the star, but rather than being a circle of light, it would be distorted as a ring around the black hole. So you'd see a donut, not a circle of light like normal stars.