Starship Asterisk*

[quote="E Fish" post_id=322468 time=1651460711 user_id=143902]
[quote]es, I've read it's still in development stages, but I didn't see a planned date. There are more telescopes joining in, I presume for more data to help with resolution and fidelity. Back when M87 was imaged, they knew that the MW BH is harder to image. I can't remember the details, but I believe the task is harder because it's smaller and maybe not as well positioned wrt its accretion disk(?).[/quote]

I seem to recall (unfortunately, not remembering the source) reading that the issue was a combination of a lot more dust in the way and [b][size=120][color=#FF0000]the black hole itself being less active than the one in M87[/color][/b][/size]. That was in addition to the fact that it's smaller than M87's.
[/quote]


[float=left][img3="5000 light-year-long jet being ejected from the vicinity of the black hole of M87. NASA/ESA and John Biretta (STScI/JHU)"]https://cdn.spacetelescope.org/archives/images/screen/opo9943c.jpg[/img3][/float][float=right][img3="In this X-ray (Chandra) and radio (VLA) composite image, hot matter (blue in X-ray) from the Virgo cluster falls toward the core of M87 and cools, where it is met by the relativistic jet (orange in radio), producing shock waves in the galaxy's interstellar medium."]https://upload.wikimedia.org/wikipedia/commons/thumb/8/83/M87_Super-Volcano.jpg/1024px-M87_Super-Volcano.jpg[/img3][/float]
[clear][/clear]


Let's hope so! :shock: 😱

Ann

[quote]es, I've read it's still in development stages, but I didn't see a planned date. There are more telescopes joining in, I presume for more data to help with resolution and fidelity. Back when M87 was imaged, they knew that the MW BH is harder to image. I can't remember the details, but I believe the task is harder because it's smaller and maybe not as well positioned wrt its accretion disk(?).[/quote]

I seem to recall (unfortunately, not remembering the source) reading that the issue was a combination of a lot more dust in the way and the black hole itself being less active than the one in M87. That was in addition to the fact that it's smaller than M87's.

[attachment=0]M87bh_EHT_2629.jpg[/attachment]
I'm stqyina away from this beast!
[attachment=1](2).jpg[/attachment]
But love cake donuts
[attachment=2].jpg[/attachment]
Scholarly kitty! 8-)

[quote=De58te post_id=322458 time=1651410558 user_id=141631]
Maybe it is a defect of my computer monitor but to me the central black shadow still looks a little brighter to me than the surrounding black at the edges of the photo. It even looks almost a shade of brown compared to the black at the edges. Although it is impossible for the star light behind the shadow to show through the black hole, maybe that brown is haze light from the stars in the galaxy in front reflecting off some dust particles that are in direct line of the black hole? But then what is producing the black shadow at the sides? Surely there must be some stars from the back portion of the galaxy visible there.
[/quote]

Note that the spatial resolution of the image is about the same size as the central shadow. In simple terms, that means that we're looking at a very blurry image, so a lot of energy in the imaged central region (as opposed to the [i]actual [/i]center region) is coming from the (imaged) ring around it. The white ring in the image below shows the resolution of the data.
_
[attachment=0]res.png[/attachment]

If you have any questions about black holes, you can ask LIGO at:

https://www.ligo.caltech.edu/page/ask-ligo

I have in the past and received a prompt, comprehensive and very informative reply.

Maybe it is a defect of my computer monitor but to me the central black shadow still looks a little brighter to me than the surrounding black at the edges of the photo. It even looks almost a shade of brown compared to the black at the edges. Although it is impossible for the star light behind the shadow to show through the black hole, maybe that brown is haze light from the stars in the galaxy in front reflecting off some dust particles that are in direct line of the black hole? But then what is producing the black shadow at the sides? Surely there must be some stars from the back portion of the galaxy visible there.

Karl Schwarzschild predicted what you see in the photo, a black hole of mass m, while fighting for Germany on the Eastern Front in World War I: http://henry.pha.jhu.edu/bigfour.png

[quote="APOD Robot" post_id=322431 time=1651377932 user_id=128559]
What does a black hole look like? ...
[/quote]

1:4 - Maybe the Donat will get legs in the future too ;-)

[img]https://live.staticflickr.com/65535/52041764539_d203ddf498_m.jpg[/img]
[size=50][url]https://live.staticflickr.com/65535/52041764539_d203ddf498_b.jpg[/url][/size]
[img]https://live.staticflickr.com/65535/52040472352_3c81b0b03f_m.jpg[/img]
[size=50][url]https://live.staticflickr.com/65535/52040472352_3c81b0b03f_b.jpg[/url][/size]
[img]https://live.staticflickr.com/65535/52041515946_675a6205db_n.jpg[/img]
[size=50][url]https://live.staticflickr.com/65535/52041515946_675a6205db_b.jpg[/url][/size]
[img]https://live.staticflickr.com/65535/52042027200_f0a4fc244c_w.jpg[/img]
[size=50][url]https://live.staticflickr.com/65535/52042027200_f0a4fc244c_b.jpg[/url][/size]
[size=50]Composit Images: Jac Berne (flickr)[/size]
[size=85]
[url]https://iopscience.iop.org/article/10.3847/2041-8213/ab0e85/pdf[/url][/size]

[quote=Ann post_id=322433 time=1651382234 user_id=129702]
Is an image of the central supermassive black hole of the Milky Way, Sgr A*, coming up? The people behind the portrait of the supermassive black hole in M87 have said that they will take a picture of Sgr A*, too. Perhaps it is coming soon?

Go to [url=https://www.youtube.com/shorts/FUBUpPdf5Eo]this "Youtube short"[/url] by Dr Becky to hear her say a few words about it.

Ann
[/quote]

Yes, I've read it's still in development stages, but I didn't see a planned date. There are more telescopes joining in, I presume for more data to help with resolution and fidelity. Back when M87 was imaged, they knew that the MW BH is harder to image. I can't remember the details, but I believe the task is harder because it's smaller and maybe not as well positioned wrt its accretion disk(?).

It looks like the EHT group will be presenting "groundbreaking" results this May 12
[url]https://www.space.com/event-horizon-telescope-milky-way-results[/url]

[quote="APOD Robot" post_id=322431 time=1651377932 user_id=128559]
...
[url=https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT]Pictured[/url], the dark central region is not the event horizon, but rather the [url=https://www.esa.int/gsp/ACT/projects/blackhole_shadows.html]black hole's shadow[/url] -- the central region of emitting gas darkened by the central black hole's gravity. The size and shape of the shadow is determined by bright gas [url=https://www.youtube.com/watch?v=t-O-Qdh7VvQ]near the event horizon[/url], by strong [url=https://apod.nasa.gov/htmltest/rjn_bht.html]gravitational lensing deflections[/url], and by the black hole's spin.
...
[/quote]

Considering a Schwarzschild BH (non-rotating), the shadow diameter is 2.6 times the event horizon diameter for a BH very far away (e.g Milky Way BH)
[url=https://arxiv.org/pdf/1910.10514.pdf]Shadow of black holes at local and cosmological distances[/url]
 
[attachment=1]BH Shadow misconeptions - Bottom view is correctJPG.jpg[/attachment]
 
[attachment=0]Face-on view.jpg[/attachment]

Is an image of the central supermassive black hole of the Milky Way, Sgr A*, coming up? The people behind the portrait of the supermassive black hole in M87 have said that they will take a picture of Sgr A*, too. Perhaps it is coming soon?

Go to [url=https://www.youtube.com/shorts/FUBUpPdf5Eo]this "Youtube short"[/url] by Dr Becky to hear her say a few words about it.

Ann

[url=https://apod.nasa.gov/apod/ap220501.html] [img]https://apod.nasa.gov/apod/calendar/S_220501.jpg[/img] [size=150]First Horizon-Scale Image of a Black Hole[/size][/url]

[b] Explanation: [/b] What does a black hole look like? To find out, [url=https://en.wikipedia.org/wiki/Radio_telescope]radio telescopes[/url] from [url=https://eventhorizontelescope.org/files/eht/files/eht_globes_physicstoday_marrone_east.jpeg]around the Earth[/url] coordinated observations of [url=https://science.nasa.gov/astrophysics/focus-areas/black-holes]black holes[/url] with the largest known [url=https://en.wikipedia.org/wiki/Event_horizon#Event_horizon_of_a_black_hole]event horizon[/url]s on the sky. Alone, black holes are just [url=https://youtu.be/JoLEIiza9Bc]black[/url], but these monster attractors are known to be surrounded by glowing gas. This first image [url=https://www.eso.org/public/usa/outreach/first-picture-of-a-black-hole/blog/]resolves[/url] the area around the [url=https://beta.nsf.gov/blackholes]black hole[/url] at the center of [url=https://apod.nasa.gov/apod/ap210415.html]galaxy M87[/url] on a scale below that expected for its [url=https://www.forbes.com/sites/startswithabang/2019/04/10/black-holes-are-real-and-spectacular-and-so-are-their-event-horizons/]event horizon[/url]. [url=https://iopscience.iop.org/journal/2041-8205/page/Focus_on_EHT]Pictured[/url], the dark central region is not the event horizon, but rather the [url=https://www.esa.int/gsp/ACT/projects/blackhole_shadows.html]black hole's shadow[/url] -- the central region of emitting gas darkened by the central black hole's gravity. The size and shape of the shadow is determined by bright gas [url=https://www.youtube.com/watch?v=t-O-Qdh7VvQ]near the event horizon[/url], by strong [url=https://apod.nasa.gov/htmltest/rjn_bht.html]gravitational lensing deflections[/url], and by the black hole's spin. In resolving [url=https://iopscience.iop.org/article/10.3847/2041-8213/ab0ec7]this black hole's shadow[/url], the [url=https://eventhorizontelescope.org/about]Event Horizon Telescope[/url] (EHT) bolstered evidence that [url=https://en.wikipedia.org/wiki/General_relativity]Einstein's gravity[/url] works even in [url=https://youtu.be/bciCbN8lc08]extreme regions[/url], and gave [url=https://previews.123rf.com/images/aleksandrrr/aleksandrrr1606/aleksandrrr160600010/60185350-gray-kitten-and-microscope.jpg]clear evidence[/url] that [url=http://chandra.si.edu/photo/2019/black_hole/]M87[/url] has a central spinning black hole of about 6 billion solar masses. Since releasing this featured image in 2019, the [url=https://eventhorizontelescope.org/science]EHT[/url] has expanded to include [url=https://eventhorizontelescope.org/array]more telescopes[/url], observe [url=https://apod.nasa.gov/apod/ap210804.html]more black holes[/url], track [url=https://apod.nasa.gov/apod/ap210331.html]polarized light[/url],and [url=https://www.inverse.com/science/milky-way-black-hole-image-prediction]is working to observe[/url] the immediately vicinity of the [url=https://apod.nasa.gov/apod/ap011029.html]black hole[/url] in [url=https://apod.nasa.gov/apod/ap180729.html]the center[/url] of our [url=https://solarsystem.nasa.gov/resources/285/the-milky-way-galaxy/]Milky Way Galaxy[/url].


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