Questions tagged [adaptive-optics]
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22
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Number of lenslets in wavefront sensor array
I have to do a short calculation, but, quite frankly, I have no idea how to even start...
Suppose you have a 10-m telescope (f/10) with an infrared camera that observes at 10 micrometer. The seeing is ...
2
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1answer
59 views
When using adaptive optics, what is the shortest timescale of atmospheric changes in refractive index that astronomers have to deal with?
I am interested in the astronomer's need for speed in wavefront correction, especially when measuring in NIR and visible domain.
What is the fastest abberation coming from atmospheric turbulence in ...
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19 views
How do HabEx's internal coronagraph and external starshade work together and complement each other? What is it that each can do that the other can't?
Limits of space telescope? links to the video 4 Future Space Telescopes NASA wants to build and that page links to The New Great Observatories. These cover the four space-based instruments proposed by ...
2
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1answer
60 views
Does a continuous deformable mirror cause diffuse reflection?
We have all seen images like this of deformable mirrors:
Continuous deformable mirrors are known to have a higher quality over segmented mirrors, but it seems to me that a continuous mirror (or even ...
3
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0answers
84 views
Deformable optics for consumer telescopes
I am aware that there are adaptive imaging techniques for amateur astronomers. But these methods correct an image on a screen. This is nice, but to me the real lure of amateur astronomy is the act of ...
2
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1answer
215 views
Why are Shack-Hartmann sensors so expensive (4k+ USD)?
Recently I am searching for a Shack-Hartmann wavefront sensor for university laboratory usage. I was expecting my target sensor to be cheap, which is:
Low spatial wavefront resolution (50 x 50) for ...
3
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4answers
176 views
Is Digital Adaptive Optics Possible?
Adaptive optics generally apply slight changes to mirrors to account for atmospheric turbulence. These generally require either a mirror to be broken up into smaller mirrors, each with their own ...
5
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1answer
118 views
Can weak gravitational lensing or microlensing-induced wavefront distortion limit resolution of absurdly large aperture telescopes?
This is a theoretical question.
This answer to the question If we had the right technology could we see a distant star in detail? (presumably space-based) primarily addresses the scaling of ...
5
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2answers
202 views
Adaptive Optics Shack-Hartmann Sensor and Deformable Mirror
I have a technical question regarding the Shack-Hartmann sensor in deformable mirrors. What algorithm is used to take the Shack-Hartmann measurements of local tilt and turn them into a full phase ...
6
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1answer
271 views
How did VLT's adaptive optics obtain this resolution for Neptune? Is it really working in visible wavelengths?
This image of Neptune taken with the VLT is really impressive. The resolution is achieved by recent improvements in the adaptive optics.
Gizmodo: New Super-Crisp Images of Neptune Show How Far Our ...
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1answer
145 views
What is tilt anisoplanatism for Laser-guide-star usage in adaptive optic systems?
How does tip-tilt mirrors correct such issue? What is the physical origin of the error?
6
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4answers
431 views
Why not use only one support vane for the secondary mirror, to avoid multiple diffraction spikes?
Each vane holding the secondary mirror in front of the primary causes a diffraction spike. Couldn't the secondary mirror be held with only one vane?
If stability is the issue, couldn't it be ...
3
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2answers
133 views
How difficult is adaptive optics computationally?
What kind of computer do you need to do adaptive optics of big telescopes? Are we talking supercomputer clusters or can my desktop do it, or my smartphone? I suppose it depends on the size of the ...
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5answers
294 views
Why was the (small) Hubble better able to find KBO targets for New Horizons than large adaptive optics ground telescopes?
When initial searches for a Kuiper Belt object for New Horizons to fly to after passing Pluto did not find good targets, the Hubble telescope was used, and it resulted in the current targeted flyby ...
7
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2answers
383 views
How large does refraction become in radioastronomy?
For atmospheric refraction of visible light, Wikipedia gives the order of 1 arc minute at 45° altitude above the horizon, and 5.3 arc minutes at 10°. This is caused by the dielectric polarizability of ...
3
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1answer
616 views
How do tip tilt mirrors correct distortion in adaptive optics?
I'm currently trying to learn about how adaptive optics correct the blurriness caused by atmospherical seeing effects. This is my current understanding of how adaptive optics works (trying to offer ...
2
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1answer
260 views
Instead of using flexible mirrors, could software be used for adaptive optics?
Telescopes that use adaptive optics now use flexible mirrors to adjust for distortions in the atmosphere. The mirrors are flexed in real time to account for the distortions. I am wondering if it ...
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0answers
71 views
Adaptive Optics observations worse than natural seeing observations for faint structures?
I have read that one drawback of Adaptive Optics (AO) IFU observations is that they have lower SNR (compared natural seeing observations) and as a result it is harder to observe faint structures. For ...
9
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1answer
141 views
V471 Tauri's circumbinary brown dwarf non-observation; Applegate, or over-restrictive assumptions?
tl;dr Has the brown dwarf observation been disproven?
I have just started reading about the interesting object V471 Tauri. The first two sentences of the introduction to The V471 Tauri System: A ...
3
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1answer
292 views
Will the E-ELT use Adaptive Optics at visible wavelengths?
In this recent BBC article I read that the European Extremely Large Telescope or E-ELT is in final design and is planned to be on line by 2024, and that (of course) it will rely heavily on adaptive ...
9
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2answers
449 views
Why aren't ground-based observatories using adaptive optics for visible wavelengths?
Adaptive Optics (AO) techniques allow ground based observatories to dramatically improve resolution by actively compensating for the effects of Astronomical Seeing.
The atmospheric effects are quite ...
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1answer
184 views
Why weren't the Hubble light-echo images of V838 Monocerotis supplemented by ground telescopes?
Drawing from this answer
The V838 Monocerotis expansion (not a supernova) and the observation of the subsequent "spectacular" light echo was quite a notable event! From Nature 422, 405-408 (27 ...
