https://www.eso.org/public/images/eso1436a/
Not exactly macro, but look at the resolution. It used to be that even the best telescopes could image stars just as single points (pixels). Now we can see a protoplanetary system in surprising detail.
resolution
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rjlittlefield
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Impressive!
Just to confirm, is this from the system described at https://en.wikipedia.org/wiki/Atacama_L ... eter_Array ?
--Rik
Just to confirm, is this from the system described at https://en.wikipedia.org/wiki/Atacama_L ... eter_Array ?
--Rik
This video introduces the instruments and their combined resolution and gives some information about the star:
https://www.eso.org/public/germany/videos/eso1436b/
plus some virtual tours
https://www.eso.org/public/products/vir ... tualtours/
Also the correlator that computes the single images into one superresolution pic is worthwile to look at:
https://www.almaobservatory.org/en/pres ... telescope/
with an updated and even more powerful version already in the works.
https://www.eso.org/public/germany/videos/eso1436b/
plus some virtual tours
https://www.eso.org/public/products/vir ... tualtours/
Also the correlator that computes the single images into one superresolution pic is worthwile to look at:
https://www.almaobservatory.org/en/pres ... telescope/
with an updated and even more powerful version already in the works.
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rjlittlefield
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- Posts: 23606
- Joined: Tue Aug 01, 2006 8:34 am
- Location: Richland, Washington State, USA
- Contact:
Taking a crack at "putting things in perspective"...
I read that ALMA can image at wavelengths down to 0.35 mm, with a maximum distance between antennas of 16 km. That works out to an aperture whose diameter is approximately 4.6E+07 lambda.
Scaling that into the visual spectrum, with lambda = 0.5 micron, the corresponding aperture would be about 23 meters.
In contrast, the largest actual earthbound telescopes have apertures around 10 meters.
So yes, ALMA does probably have some more resolution, but it's not by a large margin -- ballpark 2X or so.
My take is that the big advantage of ALMA -- the reason it can image that protoplanetary disk -- is that ALMA achieves both high resolution and high sensitivity at a wavelength where the disk has high brightness compared to the empty space behind it and the star in the center of it.
In any part of the visual spectrum, I expect that disk would not be separable from background and glare regardless of how much resolution the telescope had.
Do I have this right?
--Rik
I read that ALMA can image at wavelengths down to 0.35 mm, with a maximum distance between antennas of 16 km. That works out to an aperture whose diameter is approximately 4.6E+07 lambda.
Scaling that into the visual spectrum, with lambda = 0.5 micron, the corresponding aperture would be about 23 meters.
In contrast, the largest actual earthbound telescopes have apertures around 10 meters.
So yes, ALMA does probably have some more resolution, but it's not by a large margin -- ballpark 2X or so.
My take is that the big advantage of ALMA -- the reason it can image that protoplanetary disk -- is that ALMA achieves both high resolution and high sensitivity at a wavelength where the disk has high brightness compared to the empty space behind it and the star in the center of it.
In any part of the visual spectrum, I expect that disk would not be separable from background and glare regardless of how much resolution the telescope had.
Do I have this right?
--Rik
They claim to have a resolution 10 times that of Hubble. That would coincide with your calculations.
I have tried to read the pertinent chapters in the Handbook of Alma
https://www.iram.fr/IRAMFR/ARC/document ... ndbook.pdf
Unluckily, that is not an easy cuisine.
I have tried to read the pertinent chapters in the Handbook of Alma
https://www.iram.fr/IRAMFR/ARC/document ... ndbook.pdf
Unluckily, that is not an easy cuisine.