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Astronomers reveal first image of the black hole at the heart of our galaxy

  • 786 points
  • 8 days ago

  • @sohkamyung
  • Created a post

Astronomers reveal first image of the black hole at the heart of our galaxy


@muxneo 8 days

Replying to @sohkamyung 🎙

Size of rings prove Einstein's Theory of relativity. This is an amazing work

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@22SAS 8 days

Replying to @sohkamyung 🗣

This is some great work, kudos to the researchers working in the Event Horizon Telescope team.

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@jackallis 8 days

Replying to @sohkamyung 🗣

ithought this was old news from couple of years ago, did i miss something?

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@daniel-thompson 8 days

Replying to @sohkamyung 🗣

Very interesting. The previously-released M87 image had just a single "shadow", but this one (of Sag A*) has multiple bright "lumps". Maybe it's in the linked papers which I haven't gotten to yet, but why the difference? Is it due to the observation method or does it reflect a real difference? Or both?

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@mabbo 8 days

Replying to @sohkamyung 🗣

> “We were stunned by how well the size of the ring agreed with predictions from Einstein’s Theory of General Relativity,"

And ten thousand physicists sighed disappointingly.

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@_joel 8 days

Replying to @sohkamyung 🎙

Anton Petrov is doing a good rundown on youtube now

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@api 8 days

Replying to @sohkamyung 🗣

I'm looking forward to JWST shots of stuff like this.

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@anothernewdude 8 days

Replying to @sohkamyung 🎙

Yeah, we know. We've already seen this image.

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@murat124 8 days

Replying to @sohkamyung 🎙

This image apparently has not captured as much attention as the image of M87, but anyway, I have a question, maybe someone with the knowledge can answer:

Between the images of M87 and Sgr A, one noticeable difference is that the image of M87 appears to have a single cluster of light "below" the blackhole whereas the image of Sgr A has three surrounding the blackhole. Is this because of the mass and spin differences between the two blackholes?

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@iliketrains 8 days

Replying to @sohkamyung 🎙

This is incredible! Veritasium has a nice video explaining how those images were obtained and what they mean: https://www.youtube.com/watch?v=Q1bSDnuIPbo

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@sidcool 7 days

Replying to @sohkamyung 🎙

I still can't wrap my head around the fact that black holes are real things. And GR predicts them so accurately.

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@aaroninsf 8 days

Replying to @sohkamyung 🎙

Q: why are galaxies like ours so good at golf? A: there's usually a splendid hole in one.

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@dredmorbius 8 days

Replying to @sohkamyung 🎙

There seem to be numerous submissions of this topic.

This thread seems to be the leading one:

Astronomers Reveal First Image of the Black Hole at the Heart of Our Galaxy

https://public.nrao.edu/news/astronomers-reveal-first-image-... (https://news.ycombinator.com/item?id=31353677)

Others, as of submitting this comment:

https://www.eso.org/public/news/eso2208-eht-mw/ (https://news.ycombinator.com/item?id=31353692)

https://public.nrao.edu/news/astronomers-reveal-first-image-... (https://news.ycombinator.com/item?id=31353677)

https://www.youtube.com/watch?v=rIQLA6lo6R0 (https://news.ycombinator.com/item?id=31353643)

https://www.youtube.com/watch?v=4Ws0iPDSqI4 (https://news.ycombinator.com/item?id=31353587)

https://www.nsf.gov/news/news_summ.jsp?cntn_id=305028&org=NS... (https://news.ycombinator.com/item?id=31353583)

https://nitter.kavin.rocks/ehtelescope/status/15247172729037... (https://news.ycombinator.com/item?id=31353547)

https://www.cnet.com/science/space/watch-live-astronomers-re... (https://news.ycombinator.com/item?id=31353480)

https://beta.nsf.gov/blackholes (https://news.ycombinator.com/item?id=31353474)

https://www.youtube.com/watch?v=rIQLA6lo6R0 (https://news.ycombinator.com/item?id=31353463)

https://www.nsf.gov/news/news_summ.jsp?cntn_id=305148 (https://news.ycombinator.com/item?id=31353757)

https://eventhorizontelescope.org/blog/astronomers-reveal-fi... (https://news.ycombinator.com/item?id=31353786)

https://www.nytimes.com/2022/05/12/science/black-hole-photo.... (https://news.ycombinator.com/item?id=31353823)

https://www.quantamagazine.org/black-hole-image-reveals-sagi... (https://news.ycombinator.com/item?id=31353874)

https://www.bbc.co.uk/news/science-environment-61412463 (https://news.ycombinator.com/item?id=31353939)

https://news.ycombinator.com/item?id=31353221

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@wthomp 8 days

Replying to @sohkamyung 🎙

For those wondering if we could get sharper images with JWST, here’s the previously imaged black hole (same angular size as our own) compared to a single pixel from Hubble’s wide field camera 3:

https://twitter.com/alex_parker/status/1116070667068170240?s...

JWST will have smaller “pixels” but is in the same ballpark.

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@NelsonMinar 8 days

Replying to @sohkamyung 🎙

I love this quote, it's great popular science communication. "the brightness and pattern of the gas around Sgr A* was changing rapidly as the EHT Collaboration was observing it — a bit like trying to take a clear picture of a puppy quickly chasing its tail."

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@fasteddie31003 8 days

Replying to @sohkamyung 🎙

I am very skeptical of the Event Horizon Telescope (EHT) images because they are not following a scientific method that results in a true representative image of their target. In my opinion astronomy is jumping the shark with these images by making this a big PR stunt.

I've looked at their methods for their earlier images and they seem to be hunting for a circle that looks like a black hole in their data. The EHT's full imaging stack has never been calibrated by looking at a known celestial body to compare images to validate their algorithms. They have calibrated their signals from results of other instruments, but their imaging algorithms change to fit their wanted results. This is my biggest problem with their approach. Anyone can modify algorithms of any arbitrary data to get an image of a glowing circle. A better method that shows a more true image would be to calibrate their imaging algorithms against a known celestial body to make sure their techniques produced comparable results from other instruments. Then they should have taken their calibrated imaging algorithms and gave it data from their target.

I'd have more confidence in the EHT if they would not change their imaging algorithms across images and give a side-by-side comparison of a known celestial body that other radio telescopes have imaged to verify their whole imaging stack.

To me this a just a big PR stunt and I'm very skeptical of their image.

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@denton-scratch 8 days

Replying to @sohkamyung 🎙

I am impressed.

I have a few ignorant questions:

1. There are three bright blobs on the image; I assume they are the same object, behind the BH. What are they/is it? They said the image was averaged; so presumably whatever the blobs are wasn't moving?

2. Is it correct that the rest of the ring, ignoring the three blobs, is the far side of the accretion disk? Why can't I see this side of the accretion disk?

3. According to the article, at least one submillimeter telescope was important. But submillimeter is infrared, isn't it? I thought infrared was blocked by dust, and if there's one thing there's a lot of at the centre of the galaxy, it's dust?

[Edit] Questions 1 and two were prompted by this remark in the article:

  "The new view captures light bent by the powerful gravity of the black hole"
The only "light" I can see is a ring with blobs in it; that's why I suppose the ring in the image is not the accretion disk, at least, not as viewed from the pole. Most other commenters here assume (or know) that it is the accretion disk, and we are looking at a pole.

But if that is indeed the accretion disk, then that isn't light that's been bent by the gravity of the black hole.

Perhaps the explanation is that many other commenters haven't actually read the article, possibly because they already know the story.

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@NHQ 8 days

Replying to @sohkamyung 🎙

This image came out several years ago or I have seen the future.

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@coryfklein 8 days

Replying to @sohkamyung 🎙

I'm sorry, I am really confused. Didn't we get "the first picture of the black hole at the center of our galaxy" like 2-3 years ago? I definitely remember seeing a nearly identical photo, and lots of press coverage about a particularly young woman who was closely involved in the project. What that something different?

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@jrgd 8 days

Replying to @sohkamyung 🎙

I find the whole thing amazing and captivating - yet the image is … huh … slightly underwhelming. It looks like some gaussian blurred random image. I wish it could be the kind of crisp image JWST ‘sent’.

It’s difficult to force oneself to not romanticise these un-visible things based on artists visualisation we got accustomed to.

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@Maursault 8 days

Replying to @sohkamyung 🎙

Didn't we see this image last April? What is new here? tia

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@jack-bodine 8 days

Replying to @sohkamyung 🗣

This announcement was released simultaneously with 6 papers that use the newly released data. They are linked in the bottom of the press release and are definitely worth checking out.

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@kloch 8 days

Replying to @sohkamyung 🗣

One of the findings they announced at the press conference is that the spin of the black hole is not aligned with the galactic plane but is tilted "towards us" so that it is viewed face on.

How unexpected is that?

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@smm11 8 days

Replying to @sohkamyung 🎙

So earth will be sucked down this black hole and shredded how many days from now?

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@mescaline 8 days

Replying to @sohkamyung 🗣

> Because the black hole is about 27,000 light-years away from Earth, it appears to us to have about the same size in the sky as a donut on the Moon.

I'm still sad we can't post donut emojis here. This place sucks.

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@yawz 8 days

Replying to @sohkamyung 🎙

> EHT team members talk about a sharpness of vision akin to being able to see a bagel on the surface of the Moon.

This is truly amazing!

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@Sporktacular 8 days

Replying to @sohkamyung 🎙

I recall the EHT imaging 2 objects back in 2019 - M87 and another black hole. Does anyone remember what that was, or am I mistaken?

I thought it was Sagittarius A* back then.

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@belter 8 days

Replying to @sohkamyung 🎙

Announcement press conference:

"Press conference on Milky Way galaxy discovery from the Event Horizon Telescope collaboration"

https://youtu.be/KgvPA9RmEnk

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@leommoore 7 days

Replying to @sohkamyung 🎙

There is something cool about being able to see something so powerful in the far reaches of space as it looked 27,000 years ago.

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@bholevid34 8 days

Replying to @sohkamyung 🎙

Extremely cool video, "Meet Sgr A*: Zooming into the black hole at the centre of our galaxy":

https://www.youtube.com/watch?v=Zml0dZCjaFw

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@nyc111 8 days

Replying to @sohkamyung 🎙

Matt Strassler: «The details of the reconstructed image depend on exactly what assumptions are made.» https://profmattstrassler.com/2022/05/12/in-our-galaxys-cent...

What does this mean? If they assembled an image to fit their assumptions, that would be circular reasoning. I don't understand.

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@uwagar 8 days

Replying to @sohkamyung 🎙

tbh the image isnt inspiring. kinda like a low res computer simulation.

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@Apocryphon 8 days

Replying to @sohkamyung 🎙

Funnily enough, Arcade Fire released a new album this week, which just happens to have a song entitled Sagittarius A*

https://www.youtube.com/watch?v=rAUpD4FchZI

https://genius.com/25770411

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@ramigb 8 days

Replying to @sohkamyung 🎙

Can the smart people in here confirm if we are getting sucked into this someday or not?

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@neals 8 days

Replying to @sohkamyung 🎙

So, what kept us from pointing a camera in that direction and snapping this picture up until now?

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