All Questions
Tagged with black-hole mass
34
questions
24
votes
3
answers
4k
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From an outsider's perspective, how can a black hole grow if nothing ever crosses the event horizon?
Due to time dilation, an outside observer never sees a falling object actually cross the event horizon. I'm not referring to the optical illusion of red-shifted light making objects appear to fade ...
user52416
3
votes
1
answer
119
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What mass does an evaporating black hole have when it's schwarzschild radius equals the Planck length?
I am referring to Hawking radiation and the decrease in mass of the black hole with time
user48394
3
votes
1
answer
291
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How do you convert an uncertainty quoted in dex to a 1-sigma uncertainty?
The black hole mass measurement uncertainties from this paper https://arxiv.org/pdf/2006.15150.pdf are quoted in "dex" and are said to be equal to 0.4 dex. I have seen from certain papers ...
- 33
0
votes
2
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402
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How is light unable to escape a black hole if photons are massless? [duplicate]
I understand light will follow the curved space that the BH is causing due to its mass. I also understand that mass attracts other mass but then photons are massless.
So 0(photon) x m2 (the BH) is ...
0
votes
1
answer
167
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What actually is the mass? [closed]
Since high school, I've been told that the definition of mass is "quantity of matter" (which is absolutely wrong, I guess). If mass is actually a quantity of matter and it is a measure of ...
- 2,640
2
votes
4
answers
315
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If a black hole has the same mass as me, then why dont i suck everything at my center of mass?
So, a black hole is very dense that you can get really close to its center of mass that it has a strong pull, well, if i have the mass of a black hole that has a really small event horizon, why doesnt ...
- 59
1
vote
1
answer
2k
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If a black hole has a mass similar to a star, why does it have a different gravitational pull?
Say there is a black hole with 1 solar mass, having the sun's mass, it would have the same gravity as the sun, right? But it still has an event horizon, so why does it have such a strong gravitational ...
- 21
3
votes
1
answer
384
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What if a primordial black hole went through the Sun?
How much mass would the Sun lose to a primordial black hole that (initially) has 10 Earth masses, passing through or close to the center of the Sun at solar escape velocity? How massive would the Sun ...
- 293
5
votes
2
answers
1k
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GW190521 black hole merger total mass calculation and missing mass, how does this happen?
I have just read an article about that black hole merge event (it's in Italian):
Sette miliardi di anni fa, due mostri si unirono
What made me curious is that the article tell that a 66 solar mass ...
- 173
4
votes
1
answer
145
views
How do OGLE-III and GAIA measure the mass of free microlensing black holes?
What is the "hypothesized lower mass gap" between 2.5 and 5 solar masses? eventually links to Constraining the masses of microlensing black holes and the mass gap with Gaia DR2.
The angle of ...
- 30.7k
4
votes
3
answers
415
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Could anything consume a small black hole?
Whenever I read about black holes, it is normally involving how they devour anything that comes too close... regardless of how big anything is.
But what if it were a really small black hole vs ...
user7845
0
votes
2
answers
608
views
Black hole's gravity
Is gravity relative to volume, or size of an object?
Since a black hole is a massive star that collapses on its weight, how comes the same sun's mass, when it becomes a black hole, provides gravity ...
- 41
-1
votes
1
answer
53
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Mass of Photon and Black holes [duplicate]
The gravity caused by a black hole is said to be so strong such that even light(photons) can not escape from it. since gravity exist only in between objects with mass, How does a black hole attract a ...
- 183
1
vote
1
answer
112
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Mass of a potential black hole in a binary system
So I've been given the velocity curve, parallax and apparent magnitude of a star in a binary system with what is potentially a black hole. I've calculated from the apparent magnitude and parallax that ...
2
votes
1
answer
688
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Smallest mass of star to be a black hole? [duplicate]
It seems to me that I forgot the smallest mass of a star and its angular momentum in order to form a black hole.
So I know that electron degeneracy pressure is overcome if the core is 1.4 solar ...
- 1,872
0
votes
1
answer
340
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Need help with a simple Blackhole question
Suppose the amount of mass in a black hole doubles. Does the event horizon change? If so, how much does it change?
- 19
8
votes
2
answers
312
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Can "rogue" supermassive black holes be made this way?
Could two galaxies (one big and one small)intersect at a velocity to allow the smaller black hole to escape but not the galaxy around it?
- 1
3
votes
0
answers
357
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How does the size of a naked black hole effect its photon sphere?
What effect does the size of a black hole have on the size or density of the photon sphere and it's proximity to the horizon?
For example: A person is in space looking at 2 black holes, one of them ...
- 1
13
votes
2
answers
1k
views
Mass of black holes compared to parent star
What is the range of percentage mass of parent star left in a stellar black hole directly after its formation?
What factors determine this number for a specific case?
- 133
0
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1
answer
134
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Does our current understanding of the mass of black hole only allow for it to be located at the singularity? [duplicate]
Does the distribution of mass or density of mass inside the event horizon matter for a black hole to exist as we currently theorize? Could the mass inside the event horizon be distributed in any way ...
- 123
-1
votes
1
answer
205
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What would happen if a planet would acumulate mass continously?
If a star accretes enough mass it collapses into a black hole (I am not a physicist or an astronomer so I guess this is the simplified version).
But what would happen if a forming planet continued to ...
- 125
11
votes
2
answers
3k
views
Are there upper or lower mass limits for black holes?
Natarajan & Treister (2008) describes a practical upper limit for black hole masses at $\sim 10^{10} M_\odot$. This is all due to the black hole's interactions with nearby matter.
However, is ...
- 8,135
2
votes
2
answers
694
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Do black holes pull in and keep spacetime itself or merely warp it but ultimately let it pass through?
Forgive my 'amazing' MS-Paint skills, but this is along the lines of what i'm wondering:
Is there any situation where Scenario A occurs, or is space always dragged back out as in Scenario B?
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7
votes
2
answers
345
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Would gravitational waves be subject to external gravitational perturbations?
Given that the gravitational wave detected by LIGO was a very weak echo of a very distant event, could it have been "deviated" and distorted on its way here by a sufficiently massive black hole in ...
5
votes
1
answer
1k
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Stellar mass limits for Neutron Star and Black Holes
Don't hate on me if I am asking a very basic and straightforward thing. I have a few questions about black holes and neutron stars.
What is the mass range (in terms of solar masses) for a main ...
- 283
2
votes
3
answers
484
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Why are black holes that massive?
Today known most massive star, R136a1 weighs approximately 256 times the mass of our sun, how did supermassive black holes, with a mass of 10 billion times the sun form?
I understand, that when a ...
- 123
0
votes
2
answers
3k
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Does the event horizon of a black hole increase or decrease by adding mass?
So a black hole is a something that has enormous gravity, therefore mass accelerates faster towards it. But if the black hole double it's mass, will it's event horizon increase in length , or will it ...
- 377
2
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2
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330
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Can any stars ever form supermassive black holes?
I heard that most supermassive blackholes are not formed by stars – in fact, we aren't even sure how they're formed. But could a star, with enough mass and low enough metallicity, form a supermassive ...
- 8,135
5
votes
2
answers
1k
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Why do certain massive stars leave no remnants?
Mass and metallicity are the two main determinants for a star's fate. This is simple enough. What's more complicated is how exactly these determine the star's fate. For example, you can see in this ...
- 8,135
6
votes
1
answer
952
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Why is metallicity important in the death of stars?
I always thought that mass was the sole determinant of a star's fate. Then I saw the table here.
So why does metallicity influence a star's ability to become a black hole or neutron star? Does it have ...
- 8,135