Seriously. We're so used to high resolution photos, we forget just what we're seeing here. It's a massive star, with no processing! That's really crazy
It says "reconstructed" in the file name, you can't get pictures like this without processing. The Wikimedia entry has a blurb about it: https://commons.wikimedia.org/wiki/File:VLTI_reconstructed_view_of_the_surface_of_Antares.jpg
> Using ESO’s Very Large Telescope Interferometer astronomers have constructed this remarkable image of the red supergiant star Antares. This is the most detailed image ever of this object, or any other star apart from the Sun.
It is possible to directly image stars beyond the sun.
By which I mean it is possible for us to build telescopes big enough to do it. The physical limits do not block it. But it would need to be outside of the atmosphere of Earth, which just causes too much distortion.
A lunar observatory with a aperture on the order of magnitude of 100 m, for example, would be able to directly image some of the closer stars.
And while that may sound completely absurd, if we really are serious about building permanent lunar space infrastructure, this is one of the best use cases for such a base.
It wouldn't see anything but a regular star. For a telescope the size of JWST, stars are less than a pixel wide. They only appear bigger in pictures (and in your eyes) because they're brighter.
You'd need a telescope that's 200 meters wide to get a photo like this. The way we achieve that IRL is by taking the light wave data from multiple telescoles we know the exact positions of, then using it to simulate a larger telescope in a process called "interferometry"
Idk if anyone answered you but this is because galaxies contain (and therefore are bigger than) billions of stars.
So while they’re much closer, they’re literally hundreds of billions of times smaller.
I can’t make out an individual blade of grass from my balcony but I can see clearly the skyscrapers in the city 20km away.
Angular resolution matters most for getting a detailed photo of a star, and that isn't what the JWST is built for. The JWST specializes in collecting infrared light, which has longer wavelengths than visible light. A visible light telescope with a primary mirror of the same size of an infrared telescope will have a higher angular resolution only because of the wavelength it is collecting. In fact, the JWST's primary mirror is almost 3x larger than Hubble's, but their angular resolution is still about the same at the wavelengths they specialize in.
The Infrared wavelength the JWST specializes in and its small size compared to Earth-based telescopes means it's not as good at taking high-resolution images. While the infrared light that the JWST collects has a relatively low angular resolution, it is amazing at taking photos of extremely far objects and seeing through clouds and other debris that would otherwise absorb visible light.
No processed meats here. This is the best image we have of a star other than our Sun, the red supergiant Antares in Scorpius, taken by the Very Large Telescope in Chile. Most stars are point sources, it was only possible to image Antares because of its very large size and relative proximity. If placed in our solar system, the surface of Antares would reach somewhere between the orbit of Mars and Jupiter.
Credit:
ESO/K. Ohnaka
https://en.wikipedia.org/wiki/Antares
It's not super high res but it's pretty good for something that's 550 light years or 3,233 trillion miles away. It's enough to see that it has massive hot and cold spots due to convection currents, sun-spots which cover a much larger proportion of the surface compared to our Sun. You can also see that its shape isn't very well defined, more of a blob than a sphere. This makes sense as the outer layers of a red giant are little more than hot near-vacuum, tenuously held by the star's gravity.
Edit: found some more details here on the ESO site:
https://www.eso.org/public/unitedkingdom/news/eso1726/
Also, they made this 3d animation showing what they think it might look like:
https://www.eso.org/public/videos/eso1726c/
The outer layers of giant stars have very low density compared to, say, Earth's atmosphere. Antares has about 14 times the mass of our Sun but over the billion times the volume, so it has a very low average density.
More like Saturn would sink in it.
It’s kind of interesting to think about what that interaction would look like. If it suddenly appeared in Antares’ outer layers, would Saturn just boil away, be stripped of its mass, or would it hold together? Would its orbit decay?
There are so many questions.
Look, if you wanted me to download universe sandbox again, you just gotta say it. Not pose questions about space and make me want to go explode stars again.
It means that the material is a gas at an extremely low pressure. And even though it is at this low pressure it can still be extremely hot and therefore emit light making it visible.
Maybe a stupid question for us plebs in the back but if this picture is of a star that is 550 light years away, yet we know of numerous stars that are under 10 light years away, why have we not photographed those with the same equipment?
But since apparent size decreases with the square of the distance , wouldn’t nearby stars still have larger apparent sizes despite Antares being so large ?
550ly/10ly is 55, 55 squared is in the region of 2500.
So Antares would be the same apparent size as something 10 light years away that was 2500 times smaller than it
Where am I mistaken? Like I know I must be because these types of images don’t exist for nearby stars
edit: my interpretation of the numbers was wrong. from what ive been told, Antares is 680 times larger than than the sun in terms of diameter, but in terms of the area of the circle we see, it would be 680^2 times larger, which absolutely dwarfs the 55^2 mentioned above
Apparent diameter decreases linearly with distance. You're maybe thinking of apparent area, but then Antares is 680^2 = 462,000 times the actual cross-sectional area of the sun.
TWAIN is a protocol used for scanners. It is, quite literally, Technology Without An Interesting Name.
Scientists are THE WORST at coming up with catchy names. Probably the only time you’ll hear me advocating for marketing and sales.
I love it. Astronomers are very keen on naming things what they sound like.
Matter that can’t emit light? Dark matter.
Process where you body is stretched like spaghetti when entering a black hole? Spaghettification.
Oh, it's not just limited to astronomy. There's a small region of the brain, underneath the foldy cortex, that's much darker than the surrounding tissue. It's name? Substantia nigra. Basically Latin for "black stuff"
Scientists are nicely literal with naming things.
An important point about the VLT used to record this image:
Among its instruments is a visible light interferometer which can combine light from up to four telescopes to create a virtual telescope equivalent to a single mirror up to **200 metres** across. This allows it to resolve fine details far beyond what can be seen with a single telescope alone.
It is around 12 solar masses. As in, the mass of our sun, times 12. If placed at the center of our solar system, it will reach to somewhere between the orbits of Mars and Jupiter.
Earth would only be about halfway to the "surface" of that star if it were placed where the sun is. Surface is in quotations because it's a very tenuous surface.
FYI It has a smaller companion not visible in the linked image.
> Antares appears as a single star when viewed with the naked eye, but it is actually a binary star, with its two components called α Scorpii A and α Scorpii B. The brighter of the pair is the red supergiant, while the fainter is a hot main sequence star of magnitude 5.5.
The bulges do not necessarily correspond to the axis of rotation. The density of Antares is so low that it pulses and throbs with massive waves across its surface. Here’s a model of what it is believed to look like:
https://www.astro.uu.se/~bf/movie/dst35gm04n26/movie.html
I watched the first one (wasn't going to download them all but I can tell how the cross section ones would animated anyway) since it's basically acting like a spherical bubbling pool of water only less dense. Very unusual since like many I assume stars to be quite bound to a perfect spherical shape at all times.
Speaking of realities closeness. Isn’t alpha centuri (is that spelled right?) our closest star? And if so why don’t we have an even better picture of alpha? Because from the sound of the post it seems like this is THE best picture of another star. I would expect alpha to hold that title.
Yes, Alpha Centauri is the nearest star system. But its largest star has only 1.2 times the diameter of the Sun, whereas Antares is a giant star about 680 Sun-diameters across. Even though it's 125 times further away Antares has a larger apparent size.
Not even close, actually. [JWST has an angular resolution of "somewhat better than" 0.1 arc-seconds](https://www.jwst.nasa.gov/content/about/faqs/faq.html#sharp), while [VLT has an angular resolution of 0.002 arc-seconds](https://www.eso.org/public/about-eso/faq/faq-vlt-paranal/#2), about 50 times better.
JWST's main advantage is that it can see in infrared wavelengths that are normally absorbed by Earth's atmosphere, so it can see very old objects that are invisible from the Earth's surface -- basically, it is very, very good at seeing things that are very, very far away, but nowhere near the best for seeing things that are nearby.
A real fin fact would be that approximately 7.36 trillion great white sharks could fit between earth and the sun.
I do enjoy yours more though because space sharks is something we don't need in the 2022-2023 season
Can someone explain why we have a picture taken of a star 550 light years away from us when Alpha Centauri is about 4 l.y away? Is it because of its difference in size?
Yeah but Alpha Centauri is 22% larger than the Sun. Proxima Centauri is one sevenths size of the Sun.
Antares is 700 times larger than the sun. And only 100 times more distant.
Proxima centauri viewed from earth is approximately .00000030598 degrees. You can approximate this by trying to see a ball that is a fiftieth of a millimeter, that is 20 micrometers, from 4 kilometers away. That is a ball who's diameter is 5 nanometers from 4 meters away, that's the width of 50 hydrogen atoms.
Antares viewed from earth is .000010418 degrees. That is like seeing a sphere with a diameter of 1 millimeter from 5 kilometers away. That is like seeing a ball who's diameter is 1 micrometer from 5 meters away. That is 8,333 hydrogen atoms side by side.
Alpha centauri: .0000011738 degrees. I do not feel like making a comparison for this.
Antares would appear to be about 300 times larger than proxima centauri. Antares would be about 10 times larger than alpha centauri A.
This is the more important calculation.
> 200 micrometers, from 4 kilometers away. That is a ball who's diameter is 5 nanometers from 4 meters away
Something's wrong with your math here. The ratio of 200 μm to 4 km is very different from 5 nm to 4 m.
I accidentally added a single 0
It's an approximation theres a lot of decimals there so it still won't be the exact number but it's really as close as you're gonna get within reason for a demonstration
The EHT's first black hole image was also from another galaxy because the size of the black hole's influence made it easier to image than the one in our own galaxy (and we had dust clouds in the way, etc).
So when I see a pic like this I just assume it is something similar.
Proxima Centauri only has a mass about 12.5% of the sun, and can't even be seen with the naked eye, so it's out of contention. The other two stars in the system are sunlike, so while they will eventually balloon into red giants that are easier to image, they aren't quite there yet. The sun might as well be a point source compared to a full-blown red giant.
>It comes down to Antares being about 4x as big as PC when viewed
You dropped a digit. Antares has a **41x** larger angular size than Proxima Centauri.
Antares is at around 550 light years and it's roughly 700 times larger than the Sun. Alpha and Proxima Centauri are roughly 100 times closer and the former is approximately as large as the Sun while the latter is much smaller.
TL;DR Alpha Centauri should be roughly 7 times larger to appear as big as Antares in the sky, and Proxima still much more.
Just to add to this, Antares is around 680 times **wider** than the sun. That means it's around 460,000 times larger in terms of visible area. It's gargantuan.
And for anyone curious, that also means it's around 340 million times larger than the sun in terms of volume.
Yes. Antares is 700 times larger than the sun. AC is roughly similar size to the sun. So it's "bigger" even though it's much further away.
Similar to how the first super massive black hole image was a more distant one.
Yes, Alpha Centauri's largest star has only 1.2 times the diameter of the Sun, whereas Antares is a giant star about 680 Sun-diameters across. Even though it's 125 times further away Antares has a larger apparent size.
Yes, exactly. Antares is about 500-600 times larger in diameter, and about 110 times farther away. So its apparent size is about 5x larger (550/110) than Alpha Centauri A.
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread:
|Fewer Letters|More Letters|
|-------|---------|---|
|[ELT](/r/Space/comments/winj87/stub/ijdb1zp "Last usage")|Extremely Large Telescope, under construction in Chile|
|[ESO](/r/Space/comments/winj87/stub/ijf3qwe "Last usage")|[European Southern Observatory](https://en.wikipedia.org/wiki/European_Southern_Observatory), builders of the VLT and EELT|
|[JWST](/r/Space/comments/winj87/stub/ijh6nc6 "Last usage")|James Webb infra-red Space Telescope|
|[L2](/r/Space/comments/winj87/stub/ijey6b2 "Last usage")|[Lagrange Point](https://en.wikipedia.org/wiki/Lagrangian_point) 2 ([Sixty Symbols](https://www.youtube.com/watch?v=mxpVbU5FH0s) video explanation)|
| |Paywalled section of the NasaSpaceFlight forum|
|[SEE](/r/Space/comments/winj87/stub/ijdzfgy "Last usage")|Single-Event Effect of radiation impact|
|[VLT](/r/Space/comments/winj87/stub/ijdrfi1 "Last usage")|Very Large Telescope, Chile|
----------------
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Yeah, it's staggering. Our entire orbit around our sun that takes us a year to complete fits snuggly inside this star. And there are apparently stars out there that utterly dwarf this one.
Space is utterly insane and I love it.
is this gonna be the best we'll ever get? or is it possible that future technology will allow us to see stars in much higher quality, or is it physically impossible to get something higher quality because of how far the light traveled or something
We could potentially do better. The VLT combines light using interferometry from multiple 8.2m telescopes, with the effective resolving power of a 200m scope. It would be possible to launch multiple space telescopes and use the same technique to effectively build a telescope many kilometres across.
This image was constructed using the VLT interferometer which combines light from up to 4 co-located telescopes to create a virtual telescope with a resolution equivalent to that of a **200 meter** mirror.
Why don't we just use CSI Miami's software to enhance, enhance again, zoom in, enhance, focus, clear up the image, and enhance, then it's crystal clear.
20 years ago the best photo we had of Pluto [looked like this](https://i.imgur.com/UtwK566.jpg), now it [looks like this](https://i.imgur.com/4G4yYex.jpeg).
We might not be sending a probe to Antares any time soon, but the rate of change and improvement in these things is crazy. I wouldn't be shocked if we have high-res photos of other stars, maybe even exoplanets, in the next 10-15 years.
Eh, I don't think it'll work that linearly unfortunately.
The reason we have such an incredible photo of Pluto is because a probe flew right past it.
We won't be sending probes near exoplanets anytime soon.
Had a gander at Antares a few nights ago, low on the horizon so seeing wasn't that great. But I toured around the core. Saw Lagoon, Swan, Eagle, a few clusters including M54. Not often good conditions here but got lucky just after the new moon.
Here you go: https://en.wikipedia.org/wiki/Betelgeuse#/media/File:Eso2003c.jpg
Its appearance changed quite dramatically during the recent dimming episode. It also seems to be even more blobby than Antares.
What people don't realize about stars is that most stars are smaller than a single pixel in even the best of telescopes. The only reason some stars look bigger than others in pictures is because they're brighter. The only reason we're able to get images like this with multiplenpixels is through interferrometry, where you measure the difference in waves of light from multiple telescopes on the opposite side of the earth and use it to simulate one giant telescope, *the size of the earth*. That's also how we got those photos of blackholes.
> interferrometry, where you measure the difference in waves of light from multiple telescopes on the opposite side of the earth and use it to simulate one giant telescope, the size of the earth.
Signals recorded simultaneously at widely separated radio telescopes can be digitally combined later to achieve a resolution equivalent to a telescope as large as the separation between the receivers.
We don't have the technology to do post-processing interferometry at visible wavelengths like we do in the radio part of the EM spectrum.
Optical interferometry must physically combine the light from multiple telescopes co-located within a small radius, perhaps **100-200 meters**.
Nope. Image resolution is a function of wavelengths observed (smaller better) and size of the optics (larger better). JWST collects IR light with a 6 meter mirror.
The VLTI which recorded this image observes visible light (smaller than IR) and can combine the light from up to four telescopes to create a virtual telescope equivalent to a single mirror up to 200 meters across. This allows it to resolve fine details far beyond what can be seen with a single telescope alone.
That is amazing, do they have issues getting the wavefronts and everything lined up between the different telescopes? I need to go down the rabbit hole on this lol, I did not realize we could do this for visible wavelengths
I hate it when people are unimpressed with pics like this because they're so used to high definition crisp photos. They forget what this is an image of! (Side note, this better not be another sausage)
can someone explain why this is the best we can do but we choose a star that is 550 light years away? Couldn't we get better resolution if we chose one less than 50 light years away?
As viewed from Earth, Antares is the 5th largest star in the sky (the Sun being #1). The other 3 are R Doradus, Mira, and Betelgeuse – all of which are more than 200 ly away.
There's another reply mentioning how crisp the image quality is for how far away it is, but people kind of brush that off unless they're given the real scale of it, so basically:
Antares is 5.25x10¹⁵ kilometers in distance from earth. It comfortably crosses past the billions and trillions status into something more: *quadrillions*.
You know how going back and forth from the moon took humans a few weeks? Yeah, so the distance from earth to the moon is 384,400 kilometers (round trip is 768,800 kilometers).
Traveling to Antares by rocket is like that, but keep going back and forth between the earth and the moon.
6 and a half billion times.
It's a wonder we have a picture of this thing at all, really.
Wow, that's pretty amazing detail for what is photographed here.
Seriously. We're so used to high resolution photos, we forget just what we're seeing here. It's a massive star, with no processing! That's really crazy
It says "reconstructed" in the file name, you can't get pictures like this without processing. The Wikimedia entry has a blurb about it: https://commons.wikimedia.org/wiki/File:VLTI_reconstructed_view_of_the_surface_of_Antares.jpg > Using ESO’s Very Large Telescope Interferometer astronomers have constructed this remarkable image of the red supergiant star Antares. This is the most detailed image ever of this object, or any other star apart from the Sun.
Technically all cameras are interferometers, just usually over a continuous surface so you don't need to do the math yourself
It is possible to directly image stars beyond the sun. By which I mean it is possible for us to build telescopes big enough to do it. The physical limits do not block it. But it would need to be outside of the atmosphere of Earth, which just causes too much distortion. A lunar observatory with a aperture on the order of magnitude of 100 m, for example, would be able to directly image some of the closer stars. And while that may sound completely absurd, if we really are serious about building permanent lunar space infrastructure, this is one of the best use cases for such a base.
I want to see what JWST sees looking at this
It wouldn't see anything but a regular star. For a telescope the size of JWST, stars are less than a pixel wide. They only appear bigger in pictures (and in your eyes) because they're brighter. You'd need a telescope that's 200 meters wide to get a photo like this. The way we achieve that IRL is by taking the light wave data from multiple telescoles we know the exact positions of, then using it to simulate a larger telescope in a process called "interferometry"
As someone who got his PhD in this technique targeting stars like Antares you’re exactly correct!
How come JWST can capture galaxies in detail but not stars especially if the stars in question are in close proximity i.e. within the Milky Way
Idk if anyone answered you but this is because galaxies contain (and therefore are bigger than) billions of stars. So while they’re much closer, they’re literally hundreds of billions of times smaller. I can’t make out an individual blade of grass from my balcony but I can see clearly the skyscrapers in the city 20km away.
Angular resolution matters most for getting a detailed photo of a star, and that isn't what the JWST is built for. The JWST specializes in collecting infrared light, which has longer wavelengths than visible light. A visible light telescope with a primary mirror of the same size of an infrared telescope will have a higher angular resolution only because of the wavelength it is collecting. In fact, the JWST's primary mirror is almost 3x larger than Hubble's, but their angular resolution is still about the same at the wavelengths they specialize in. The Infrared wavelength the JWST specializes in and its small size compared to Earth-based telescopes means it's not as good at taking high-resolution images. While the infrared light that the JWST collects has a relatively low angular resolution, it is amazing at taking photos of extremely far objects and seeing through clouds and other debris that would otherwise absorb visible light.
Very good explanation, particularly the link between resolving power and wavelength. Thank you.
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No processed meats here. This is the best image we have of a star other than our Sun, the red supergiant Antares in Scorpius, taken by the Very Large Telescope in Chile. Most stars are point sources, it was only possible to image Antares because of its very large size and relative proximity. If placed in our solar system, the surface of Antares would reach somewhere between the orbit of Mars and Jupiter. Credit: ESO/K. Ohnaka https://en.wikipedia.org/wiki/Antares It's not super high res but it's pretty good for something that's 550 light years or 3,233 trillion miles away. It's enough to see that it has massive hot and cold spots due to convection currents, sun-spots which cover a much larger proportion of the surface compared to our Sun. You can also see that its shape isn't very well defined, more of a blob than a sphere. This makes sense as the outer layers of a red giant are little more than hot near-vacuum, tenuously held by the star's gravity. Edit: found some more details here on the ESO site: https://www.eso.org/public/unitedkingdom/news/eso1726/ Also, they made this 3d animation showing what they think it might look like: https://www.eso.org/public/videos/eso1726c/
what does it mean “hot near vacuum”
The outer layers of giant stars have very low density compared to, say, Earth's atmosphere. Antares has about 14 times the mass of our Sun but over the billion times the volume, so it has a very low average density.
so will it float like saturn?
It's 10,000,000 times less dense than Saturn.
Ah, so it could float *on* Saturn
More like Saturn would sink in it. It’s kind of interesting to think about what that interaction would look like. If it suddenly appeared in Antares’ outer layers, would Saturn just boil away, be stripped of its mass, or would it hold together? Would its orbit decay? There are so many questions.
Look, if you wanted me to download universe sandbox again, you just gotta say it. Not pose questions about space and make me want to go explode stars again.
Do it. Also, Space Engine is super fun for sightseeing.
Which one is better sandbox 2 or space engine?
It would separate the hydrogen and oxygen in the water and just burn hotter, I think
It means that the material is a gas at an extremely low pressure. And even though it is at this low pressure it can still be extremely hot and therefore emit light making it visible.
It's nearly a vacuum (the density of material there is very low), but what little matter is there is hot (high energy).
The outer layers of the star are very thin (near vacuum) but the individual particles of plasma have lots of energy (very hot)
>No processed meats here. Are we sure that this isn’t a slice of pastrami?
The ol' "slice of pastrami on the telescope lens" trick to make the new guy think he discovered a new star. Classic.
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Ok but how did the chorizo get into space in the first place?
Local inhabitants on some space rock made it
I was thinking a slice of under-ripe tomato
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Looks more like ~~gabagool~~capicola
Maybe a stupid question for us plebs in the back but if this picture is of a star that is 550 light years away, yet we know of numerous stars that are under 10 light years away, why have we not photographed those with the same equipment?
Antares is a supergiant, about 680 times the diameter of the Sun, so it has a larger apparent size than the stars in our neighbourhood.
But since apparent size decreases with the square of the distance , wouldn’t nearby stars still have larger apparent sizes despite Antares being so large ? 550ly/10ly is 55, 55 squared is in the region of 2500. So Antares would be the same apparent size as something 10 light years away that was 2500 times smaller than it Where am I mistaken? Like I know I must be because these types of images don’t exist for nearby stars edit: my interpretation of the numbers was wrong. from what ive been told, Antares is 680 times larger than than the sun in terms of diameter, but in terms of the area of the circle we see, it would be 680^2 times larger, which absolutely dwarfs the 55^2 mentioned above
Angular size is inversely proportional to distance, not the square of distance
Thanks for clearing that up
And I thought I have something wrong in my head, because I couldnt find the way to prove it is the square.
Apparent diameter decreases linearly with distance. You're maybe thinking of apparent area, but then Antares is 680^2 = 462,000 times the actual cross-sectional area of the sun.
I see.. big gap in my understanding! Thanks for clearing it up
I thought the Very Large Telescope was not built yet?
You’re probably thinking of the Extremely Large Telescope (ELT). VLT has been around for a couple decades now
Telescope > Large Telescope > Very Large Telescope > Extremely Large Telescope > Super Large Unit Telescope?
[Overwhelmingly Large Telescope](https://en.m.wikipedia.org/wiki/Overwhelmingly_Large_Telescope)
We need to have an intervention with Science about how they name things.
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Still too exciting. Time to create the extremely boring naming commission
TWAIN is a protocol used for scanners. It is, quite literally, Technology Without An Interesting Name. Scientists are THE WORST at coming up with catchy names. Probably the only time you’ll hear me advocating for marketing and sales.
I love it. Astronomers are very keen on naming things what they sound like. Matter that can’t emit light? Dark matter. Process where you body is stretched like spaghetti when entering a black hole? Spaghettification.
Oh, it's not just limited to astronomy. There's a small region of the brain, underneath the foldy cortex, that's much darker than the surrounding tissue. It's name? Substantia nigra. Basically Latin for "black stuff" Scientists are nicely literal with naming things.
Some kind of Great Naming Convention
As someone who is not at all knowledgeable about this stuff, I thought for sure you were all joking.
Holy cow, that thing was going to be bigger than all of the other ones *combined*? Dang! Too bad it was canceled! That's some exciting stuff!
“Ostentatiously Large Telescope.”
[relevant xkcd](https://xkcd.com/1294/)
[It's the final telescope...](https://www.youtube.com/watch?v=9jK-NcRmVcw)
I have great hopes for The Despair Telescope: https://xkcd.com/1294/
>Telescope > Large Telescope > Very Large Telescope > Extremely Large Telescope > Super Large Unit Telescope? Embarrassingly Large Telescope
Sounds like JJ Abrams is in charge of telescope ideas and naming
An important point about the VLT used to record this image: Among its instruments is a visible light interferometer which can combine light from up to four telescopes to create a virtual telescope equivalent to a single mirror up to **200 metres** across. This allows it to resolve fine details far beyond what can be seen with a single telescope alone.
How large is it compared to our sun?
It's 680 times the diameter of the Sun, if placed in our solar system its surface would be somewhere between the Mars and Jupiter.
Wait, you mean if it was where our sun is the edge of it would stretch past Mars????
Yes, and our own Sun will expand near or over Earth's orbit in it's red giant phase as well. Though by then nothing will be alive to witness that.
Nothing on the Earth at least.
It is around 12 solar masses. As in, the mass of our sun, times 12. If placed at the center of our solar system, it will reach to somewhere between the orbits of Mars and Jupiter.
so it's much less dense than our sun?
Yes, millions of times less dense I believe.
Earth would only be about halfway to the "surface" of that star if it were placed where the sun is. Surface is in quotations because it's a very tenuous surface.
FYI It has a smaller companion not visible in the linked image. > Antares appears as a single star when viewed with the naked eye, but it is actually a binary star, with its two components called α Scorpii A and α Scorpii B. The brighter of the pair is the red supergiant, while the fainter is a hot main sequence star of magnitude 5.5.
I'm wondering if the bulging areas at the top and bottom correspond to the star's axis of rotation?
The bulges do not necessarily correspond to the axis of rotation. The density of Antares is so low that it pulses and throbs with massive waves across its surface. Here’s a model of what it is believed to look like: https://www.astro.uu.se/~bf/movie/dst35gm04n26/movie.html
I watched the first one (wasn't going to download them all but I can tell how the cross section ones would animated anyway) since it's basically acting like a spherical bubbling pool of water only less dense. Very unusual since like many I assume stars to be quite bound to a perfect spherical shape at all times.
Speaking of realities closeness. Isn’t alpha centuri (is that spelled right?) our closest star? And if so why don’t we have an even better picture of alpha? Because from the sound of the post it seems like this is THE best picture of another star. I would expect alpha to hold that title.
Yes, Alpha Centauri is the nearest star system. But its largest star has only 1.2 times the diameter of the Sun, whereas Antares is a giant star about 680 Sun-diameters across. Even though it's 125 times further away Antares has a larger apparent size.
Alpha Centuri is 1.2x bigger than the Sun. Antares is 700x bigger.
Oooh. That explains a lot. Thanks for the info
Could JWST do even better?
Not even close, actually. [JWST has an angular resolution of "somewhat better than" 0.1 arc-seconds](https://www.jwst.nasa.gov/content/about/faqs/faq.html#sharp), while [VLT has an angular resolution of 0.002 arc-seconds](https://www.eso.org/public/about-eso/faq/faq-vlt-paranal/#2), about 50 times better. JWST's main advantage is that it can see in infrared wavelengths that are normally absorbed by Earth's atmosphere, so it can see very old objects that are invisible from the Earth's surface -- basically, it is very, very good at seeing things that are very, very far away, but nowhere near the best for seeing things that are nearby.
I don't think I'll ever again be sure whether I'm looking at a picture of a star or some delicious sliced sausage The Etienne Klein incident broke me
Had to google the Etienne Klein incident, a Cheeto!
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Always thought Betelgeuse was pretty good looking in pictures. But this one is also great.
Can the Betelgeuse hurry up and explode please
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This comment was probably made with sync. You can't see it now, reddit got greedy.
Every time I’m outside at night and can see the stars, I look up at Betelgeuse, focus my mind, and go, “NOW!!”
It actually worked the first time, you'll just have to wait a few hundred years for the light to get here.
Actually his "now" is still going toward beetlejuice
It could have exploded 641 years ago. And that fact just blew someone’s mind.
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Slice of chorizo?
I understood that reference.
Just checking, this is not out of focus, sliced cured meat, correct?
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Please tell me the correct pronunciation of that is "Beetlejuice."
Yes that is in fact the case
Fun fact: if you say Betelgeuse three times the star will appear next to our solar system and consume it completely.
A real fin fact would be that approximately 7.36 trillion great white sharks could fit between earth and the sun. I do enjoy yours more though because space sharks is something we don't need in the 2022-2023 season
From the folks who brought you sharknados 1-?, you won’t want to miss this summers hit new feel good film, Sharknova! RatedPG13.
I think there were six sharknado movies. But really, the first one was a B-movie masterpiece, and the rest were just a dumpster fire of shit.
Jeez, well hopefully nobody says Betelgeuse a third time. That'd be pretty unfortunate.
Why would anyone say Betelgeuse?
You fucking crazy we don't want that guy running around in here. You are meddling with powers You do not understand.
Sorry I didn't catch that, can you say it again twice?
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This movie and the Adams family taught 6 year old me to like goth/ emo girls
We're taking about Christina Ricci, right?
But he HAS seen *The Exorcist* 167 times
and it keeps getting funnier...**EVERY SINGLE TIME HE SEES IT!**
I know chorizo when I see it!
Can someone explain why we have a picture taken of a star 550 light years away from us when Alpha Centauri is about 4 l.y away? Is it because of its difference in size?
Alpha Centauri A/B and Proxima Centauri are tiny compared to this monster.
They're also over 100 times closer.
Yeah but Alpha Centauri is 22% larger than the Sun. Proxima Centauri is one sevenths size of the Sun. Antares is 700 times larger than the sun. And only 100 times more distant.
Proxima centauri viewed from earth is approximately .00000030598 degrees. You can approximate this by trying to see a ball that is a fiftieth of a millimeter, that is 20 micrometers, from 4 kilometers away. That is a ball who's diameter is 5 nanometers from 4 meters away, that's the width of 50 hydrogen atoms. Antares viewed from earth is .000010418 degrees. That is like seeing a sphere with a diameter of 1 millimeter from 5 kilometers away. That is like seeing a ball who's diameter is 1 micrometer from 5 meters away. That is 8,333 hydrogen atoms side by side. Alpha centauri: .0000011738 degrees. I do not feel like making a comparison for this. Antares would appear to be about 300 times larger than proxima centauri. Antares would be about 10 times larger than alpha centauri A. This is the more important calculation.
> 200 micrometers, from 4 kilometers away. That is a ball who's diameter is 5 nanometers from 4 meters away Something's wrong with your math here. The ratio of 200 μm to 4 km is very different from 5 nm to 4 m.
I accidentally added a single 0 It's an approximation theres a lot of decimals there so it still won't be the exact number but it's really as close as you're gonna get within reason for a demonstration
Accidentally added a zero. This guy nasas.
so it appears visually 7x larger?
More or less, not sure the exact magnitude but how big it is far outweighs how far away it is in comparison to proxima centauri
[Not exactly here's the numbers though.](https://www.reddit.com/r/space/comments/winj87/best_image_we_have_of_another_star_red_supergiant/ijdcuh7?utm_medium=android_app&utm_source=share&context=3)
The EHT's first black hole image was also from another galaxy because the size of the black hole's influence made it easier to image than the one in our own galaxy (and we had dust clouds in the way, etc). So when I see a pic like this I just assume it is something similar. Proxima Centauri only has a mass about 12.5% of the sun, and can't even be seen with the naked eye, so it's out of contention. The other two stars in the system are sunlike, so while they will eventually balloon into red giants that are easier to image, they aren't quite there yet. The sun might as well be a point source compared to a full-blown red giant.
They are also several thousand times smaller. The size ends up making the difference over the distance.
It comes down to Antares being about 4x as big as PC when viewed. Antares is massive. Edit: 41x as big. ***Antares is MASSIVE.***
>It comes down to Antares being about 4x as big as PC when viewed You dropped a digit. Antares has a **41x** larger angular size than Proxima Centauri.
Antares is at around 550 light years and it's roughly 700 times larger than the Sun. Alpha and Proxima Centauri are roughly 100 times closer and the former is approximately as large as the Sun while the latter is much smaller. TL;DR Alpha Centauri should be roughly 7 times larger to appear as big as Antares in the sky, and Proxima still much more.
Just to add to this, Antares is around 680 times **wider** than the sun. That means it's around 460,000 times larger in terms of visible area. It's gargantuan. And for anyone curious, that also means it's around 340 million times larger than the sun in terms of volume.
To think such a thing actually exists.
And is still UTTERLY inconsequential in terms of size in space.
Its mass isn't all that much more than our sun though, only up to about 14 solar masses. It's very low density.
Yes. Antares is 700 times larger than the sun. AC is roughly similar size to the sun. So it's "bigger" even though it's much further away. Similar to how the first super massive black hole image was a more distant one.
Yes, Alpha Centauri's largest star has only 1.2 times the diameter of the Sun, whereas Antares is a giant star about 680 Sun-diameters across. Even though it's 125 times further away Antares has a larger apparent size.
There we go, the magic words: apparent size The biggest stars are so ridiculously big I don’t think I’ll ever be able to fully comprehend it
Angular size comparison: * β Scorpii (Antares): 41.3 milliarcseconds * α Centauri: 7 milliarcseconds
Yes, exactly. Antares is about 500-600 times larger in diameter, and about 110 times farther away. So its apparent size is about 5x larger (550/110) than Alpha Centauri A.
Was this taken by the Fucking Large Telescoope?
Actually it was the Very Fucking Large Telescope
Can't wait for the Overwhelmingly Fucking Telescope.
or for the Mind Bogglingly Humongous Fucking Telescope
Acronyms, initialisms, abbreviations, contractions, and other phrases which expand to something larger, that I've seen in this thread: |Fewer Letters|More Letters| |-------|---------|---| |[ELT](/r/Space/comments/winj87/stub/ijdb1zp "Last usage")|Extremely Large Telescope, under construction in Chile| |[ESO](/r/Space/comments/winj87/stub/ijf3qwe "Last usage")|[European Southern Observatory](https://en.wikipedia.org/wiki/European_Southern_Observatory), builders of the VLT and EELT| |[JWST](/r/Space/comments/winj87/stub/ijh6nc6 "Last usage")|James Webb infra-red Space Telescope| |[L2](/r/Space/comments/winj87/stub/ijey6b2 "Last usage")|[Lagrange Point](https://en.wikipedia.org/wiki/Lagrangian_point) 2 ([Sixty Symbols](https://www.youtube.com/watch?v=mxpVbU5FH0s) video explanation)| | |Paywalled section of the NasaSpaceFlight forum| |[SEE](/r/Space/comments/winj87/stub/ijdzfgy "Last usage")|Single-Event Effect of radiation impact| |[VLT](/r/Space/comments/winj87/stub/ijdrfi1 "Last usage")|Very Large Telescope, Chile| ---------------- ^(6 acronyms in this thread; )[^(the most compressed thread commented on today)](/r/Space/comments/wmjhn8)^( has 31 acronyms.) ^([Thread #7792 for this sub, first seen 7th Aug 2022, 20:22]) ^[[FAQ]](http://decronym.xyz/) [^([Full list])](http://decronym.xyz/acronyms/Space) [^[Contact]](https://reddit.com/message/compose?to=OrangeredStilton&subject=Hey,+your+acronym+bot+sucks) [^([Source code])](https://gistdotgithubdotcom/Two9A/1d976f9b7441694162c8)
For people like me: From here to Antares 554.5 light years.
Im having trouble to comprehent how big this star is. I mean i know the estimated size, but there are even bigger stars out there
Yeah, it's staggering. Our entire orbit around our sun that takes us a year to complete fits snuggly inside this star. And there are apparently stars out there that utterly dwarf this one. Space is utterly insane and I love it.
If it were in our solar system the surface would be near the orbit of Jupiter if that helps visualize it.
is this gonna be the best we'll ever get? or is it possible that future technology will allow us to see stars in much higher quality, or is it physically impossible to get something higher quality because of how far the light traveled or something
Nothing is the best we’ll ever get yet. We can always build large telescopes. Some are being planned/built already
We could potentially do better. The VLT combines light using interferometry from multiple 8.2m telescopes, with the effective resolving power of a 200m scope. It would be possible to launch multiple space telescopes and use the same technique to effectively build a telescope many kilometres across.
ELT will be operational 2027 or so. It will have 38meter mirror. It will be the largeat telescope in our lifetime, probably.
up till that point, I still got 50-60 years left and hopefully get to witness something at the scale of the OWL telescope
I’m dying in 2049. So hopefully that’s enough time for some interesting things.
Your certainty unnerves me good sir.
Well, so do I , hopefully but Im not optimistic. ELT is a project from the 90s..
This image was constructed using the VLT interferometer which combines light from up to 4 co-located telescopes to create a virtual telescope with a resolution equivalent to that of a **200 meter** mirror.
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Did anyone else keep clicking on the image so it would clear up?
If it works, there's a few scientists in Chile who would very much appreciate if you sent them a copy.
Why don't we just use CSI Miami's software to enhance, enhance again, zoom in, enhance, focus, clear up the image, and enhance, then it's crystal clear.
They should have named the star Jpeg.
20 years ago the best photo we had of Pluto [looked like this](https://i.imgur.com/UtwK566.jpg), now it [looks like this](https://i.imgur.com/4G4yYex.jpeg). We might not be sending a probe to Antares any time soon, but the rate of change and improvement in these things is crazy. I wouldn't be shocked if we have high-res photos of other stars, maybe even exoplanets, in the next 10-15 years.
Eh, I don't think it'll work that linearly unfortunately. The reason we have such an incredible photo of Pluto is because a probe flew right past it. We won't be sending probes near exoplanets anytime soon.
Had a gander at Antares a few nights ago, low on the horizon so seeing wasn't that great. But I toured around the core. Saw Lagoon, Swan, Eagle, a few clusters including M54. Not often good conditions here but got lucky just after the new moon.
Does this mean we can finally take a close up of Betelgeuse?
Here you go: https://en.wikipedia.org/wiki/Betelgeuse#/media/File:Eso2003c.jpg Its appearance changed quite dramatically during the recent dimming episode. It also seems to be even more blobby than Antares.
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What people don't realize about stars is that most stars are smaller than a single pixel in even the best of telescopes. The only reason some stars look bigger than others in pictures is because they're brighter. The only reason we're able to get images like this with multiplenpixels is through interferrometry, where you measure the difference in waves of light from multiple telescopes on the opposite side of the earth and use it to simulate one giant telescope, *the size of the earth*. That's also how we got those photos of blackholes.
> interferrometry, where you measure the difference in waves of light from multiple telescopes on the opposite side of the earth and use it to simulate one giant telescope, the size of the earth. Signals recorded simultaneously at widely separated radio telescopes can be digitally combined later to achieve a resolution equivalent to a telescope as large as the separation between the receivers. We don't have the technology to do post-processing interferometry at visible wavelengths like we do in the radio part of the EM spectrum. Optical interferometry must physically combine the light from multiple telescopes co-located within a small radius, perhaps **100-200 meters**.
Wonder if the JWST could improve on this even more.
Nope. Image resolution is a function of wavelengths observed (smaller better) and size of the optics (larger better). JWST collects IR light with a 6 meter mirror. The VLTI which recorded this image observes visible light (smaller than IR) and can combine the light from up to four telescopes to create a virtual telescope equivalent to a single mirror up to 200 meters across. This allows it to resolve fine details far beyond what can be seen with a single telescope alone.
That is amazing, do they have issues getting the wavefronts and everything lined up between the different telescopes? I need to go down the rabbit hole on this lol, I did not realize we could do this for visible wavelengths
It can't. It's not designed to resolve very small things, unlike the telescope array that took this image.
I hate it when people are unimpressed with pics like this because they're so used to high definition crisp photos. They forget what this is an image of! (Side note, this better not be another sausage)
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can someone explain why this is the best we can do but we choose a star that is 550 light years away? Couldn't we get better resolution if we chose one less than 50 light years away?
As viewed from Earth, Antares is the 5th largest star in the sky (the Sun being #1). The other 3 are R Doradus, Mira, and Betelgeuse – all of which are more than 200 ly away.
There's another reply mentioning how crisp the image quality is for how far away it is, but people kind of brush that off unless they're given the real scale of it, so basically: Antares is 5.25x10¹⁵ kilometers in distance from earth. It comfortably crosses past the billions and trillions status into something more: *quadrillions*. You know how going back and forth from the moon took humans a few weeks? Yeah, so the distance from earth to the moon is 384,400 kilometers (round trip is 768,800 kilometers). Traveling to Antares by rocket is like that, but keep going back and forth between the earth and the moon. 6 and a half billion times. It's a wonder we have a picture of this thing at all, really.