Event Horizon - Black Hole Live

[Eric Mc]

Live coverage of revelation of first ever genuine image of a black hole.

https://www.youtube.com/watch?v=lnJi0Jy692w

[Eric Mc]

It's at the centre of this galaxy - M87



Although it doesn't look that spectacular, it's been known for a while that there is a jet being shot out from the centre of this galaxy - a strong indicator that there was a black hole lurking at the centre -



It is over 53 million light years from earth.

[Eric Mc]

AshVX220 said:

Is that lower image CGI, or an actual photo? CGI surely?

Genuine - it's from the Hubble Space Telescope.

(By galactic jet standards, it's not that spectacular).

[Eric Mc]

julian64 said:

I'm underwhelmed, but probably because I'm a bit stupid.

What am I actually looking at that is a black hole and not the effect or it. Is this hawking radiation converted into the visible spectrum?
I don't understand

Yes - you are actually looking at the black hole itself which is surrounded by glowing radiation of matter as it spirals down into it.

The significant aspect of this image is that it is the first ever time we have seen this for real - although it has been speculated about for decades and we have seen countless artist impressions of what such a situation might look like.

Now we have seen the real thing.

[Eric Mc]

That's the mystery.

[Eric Mc]

Or an x-ray generator. These things are super duper dynamos.

[Eric Mc]

They were referring to the black part of the image as the "shadow". By definition, you cannot see a black hole as to see it, it needs to emit or reflect light. By definition, a black hole can do neither of these things. However, the intense gravity it creates certainly affects matter orbiting it or falling into it and the radiation created by this matter as it spirals towards the hole itself is what causes the glow surrounding it.

The image does seem to show that the glow is not uniform around the black home, which could indicate that the gravitational field surrounding the black hole is not uniform - or it could indicate that the mass of the matter falling towards or orbiting the black hole is not uniform - or it might just be down to the inability of the techniques being used to create the image to resolve detail sufficiently accurately.

It will be interesting as they improve the resolving capability of this methodology and also as they look at other black hole candidate objects to see how other black holes and their surroundings look like. I bet there will be many variations.

[Eric Mc]

eharding said:

...or, you could always go and look for yourself

Just trying to get to grips with some shiny new astronomy kit - an 8 inch Ritchey–Chrétien and a Zwo ASI 294MC cooled camera - should really be doing ~300 second sub exposures and stacking, but I thought what the hell, and ran a 2000 second exposure on M87 last night with the camera at -15C and a nebula filter, and with stretching the levels a bit I think I have managed to image the M87 jet at least....





Some really horrible amp glow in other parts of the image, but I'll try and have a go at some sub exposure and stacking tonight.

The Hubble is also a Ritchey–Chrétien design - hyperbolic Cassegrain, but a bit more expensive than mine.

That is impressive. It does indeed look like you have captured the jet.

[Eric Mc]

I am really disappointed and saddened by this type of reaction to this story. Have people REALLY lost total confidence in EVERY aspect of scientific endeavour to the point that they think this is all somehow made up?

That is truly shocking to me and a reflection on the state of mind of those who post such comments rather than the honest endeavour of the scientists and engineers who made such a huge effort to obtain these results.

I sometimes feel we are entering a new Dark Age - an age where everything is doubted and nothing is trusted. Facts are dismissed and honest toil discouraged.

What a disaster for Western society.

[Eric Mc]

julian64 said:

Eric Mc said:

I am really disappointed and saddened by this type of reaction to this story. Have people REALLY lost total confidence in EVERY aspect of scientific endeavour to the point that they think this is all somehow made up?

That is truly shocking to me and a reflection on the state of mind of those who post such comments rather than the honest endeavour of the scientists and engineers who made such a huge effort to obtain these results.

I sometimes feel we are entering a new Dark Age - an age where everything is doubted and nothing is trusted. Facts are dismissed and honest toil discouraged.

What a disaster for Western society.

Too much doom and gloom as ever Eric. You are effectively arguing for sound bite science. The vast majority of people will see the news. Either be totally uninterested or clap. The disinterest or clapping will last about 5 seconds until the next news item comes on. The depth of understanding is shallow and sound bite.

Some of us go away and try to understand what's going on. We search the internet, we post on general discussion or even may get as far as looking on specialist websites. We admit to a lack of understanding and try to learn more. This has peaked my interest to go explore beyond the sound bite news. Should I just stop and clap? I think the only dark age here is the way you perceive query as criticism.

Only in my humble opinion so far, the amazing thing about this is the degree to which collaboration turned the planet into a telescope but I think you need to acknowledge the limitations of this and that the picture may not be as important as the collaboration.

It's amazing in many ways - and a great success. I certainly didn't just watch the "soundbite" news version of it - having sat through the entire live presentation by the team and having read about the large baseline techniques they used going back a couple of decades.

What annoys me are those people who immediately start doubting the veracity and integrity of the scientists involved. That's what concerns me.

[Eric Mc]

I've seen some of her talks. She's very good.

[Eric Mc]

Like planetary rings.

[Eric Mc]

dukeboy749r said:

I thought a Black Hole was actually a sphere? If so, why would the orbiting material form a disc? and if it does, in which plane would it form?

It's a natural consequence of material orbiting a spinning mass. It's the same reason why planetary discs form. Even if the material started off as a spherical cloud surrounding the central mass - eventually, over time, the sphere of matter settles into a disc shape.

It's also the process that gives rise to proto-planetary discs around new stars - which discs end up being the planets orbiting that star.

And the same process that creates spiral or elliptical galaxies.

[Eric Mc]

AshVX220 said:

So the planets of our solar system orbit the Sun on the same plane? Is the angle of that plan dictated by the angle/direction of the Sun's spin?

The original cloud that started the solar system off had a single rotational direction. Over millions of years, this rotating sphere of matter flattened out to form a disc - expect at the very centre where the bulk of matter settled into a spherical shape and eventually underwent a fusion moment and became a star. Meanwhile further out, the disc became more pronounced. Within that disks there were spherical clumps which eventually formed planets and moons.

We seem the same process operate at lots of different scales - from galactic discs with globular centres (which almost always contain a black hole at their centre), to solar system type discs down to individual planetary bodies with discs of dust and gas.

The bulk of planetary bodies and moons within the solar system do follow a unidirectional traffic pattern on a level plane. There are some exceptions however.

[Eric Mc]

It's one of the reasons why Pluto was reclassified. Almost be definition, a planet orbits in the same plane as the other planets. However, even that is a bit arbitrary - we even know now that there are wandering planets that drift between the stars. It's most likely that such planets were once well behaved members of their own solar system but due to some gravitational interaction with another body, had themselves flung out of their solar system.

In our own solar system we have a number of moons which circle their parent planets "the wrong way" - these are likely to have been captured by the parent planet long after the planet and its original moons had been formed.

[Eric Mc]

Let's not get into yet another "Pluto Status" discussion. They've been done to death here and elsewhere.

The chat was about why material orbiting a central body has a tendency to form into a disc shape.

[Eric Mc]

Colonel D said:

Forgive my ignorance if this is stupid.
Now they've discovered this black hole can it be followed/observed from here on? Meaning we get to follow it as it moves along, seeing if it encounters a star big enough for us to see, and what happens when they come together.

I'm struggling to understand this as it is but fascinated at the same time.

This particular black hole lives at the centre of a fairly large elliptical galaxy p- so it won't be hard to follow. All we have to do is locate the galaxy - which is easily spotted with the right type of telescopic equipment - and that's where the black hole will be.

[Eric Mc]

It's pretty much expected that all galaxies have a massive black hole at their centres - including our own. The trick that this team had was that they identified the type of galaxy and the nearest one of that type where it might be possible to see into the heart of the galaxy and thereby image the black hole at the centre. The galaxy in Andromeda (M31) , for example, is quite a bit closer to us but the angle at which we see it and the amount of dust it contains would make its black hole much more difficult to spot.

It was also known that this galaxy had a huge jet shooting out of its centre, which is a sure sign that there is a powerful black hole at work in the centre of the galaxy.

Over the next few years I fully expect that other black holes in other galactic centres will be imaged.,

[Eric Mc]

AshVX220 said:

Firstly, thanks to the replies to my questions on this thread and others. I know I could google the questions I have, but that would return a ton of options and many of those may not be written in ways I understand. The knowledge in this forum is fantastic and they way those knowledgeable people convey that information is easy for a layman like me to understand.

Secondly, do we think Black Holes only exist at the centre of galaxies, or is there evidence/a theory that they may exist in other parts of a galaxy? Is a Black Hole to a Galaxy what the Sun is to our Solar System only? is it only the Black Hole that keeps a Galaxy together?

Finally, back to the disks of matter orbiting things, does this mean that given enough time, the matter around Saturn (for example) would eventually form more moons? It seems an obvious conclusion to me.

It is expected the centre of all galaxies contain a very large black hole. They are the gravitational points that hold the whole conglomeration of stars together.

Any star over a certain mass is likely to collapse into a black hole as it approaches the end of its life i.e. it has run out of fuel to keep the nuclear fusion process running. Therefore, it is almost definite that galaxies contain millions of such black holes which orbit the galactic centre - just as they did when they were shining stars.

Regarding rings around planets - these all orbit their parent planet within a radius called the Roche Limit. This is a zone around a planet where the gravitational pull of the planet creates a tidal effect on the matter which prevents it from clumping together to form larger bodies such as decent sized moons - so the matter stays diffuse and spread out.