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2answers
42 views

Solar Elevation Angles — Anomaly?

"The solar elevation angle is the altitude of the sun, the angle between the horizon and the centre of the sun's disc." - Wikipedia The meridian is when the sun is directly facing earth and is at ...
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2answers
62 views

Would Adaptive Optics be Useful in Radio Astronomy?

This Question and Answer got me thinking. If atmospheric seeing at visible wavelengths is the result of refractive index inhomogeneity, would it also be a similar problem for mm to cm wavelengths? ...
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1answer
48 views

Seconds of Arc and the Unaided Eye

I've been presented with this problem: Say that Jupiter, with its diameter of 142,000 km, was located where Mars now orbits. What would be the angular size of (the newly-relocated) Jupiter ...
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0answers
48 views

What would be the maximum theoretically possible angular resolution?

I have studied some basic astronomy, but I have difficulty conceptualizing the physics of luminosity and optics. We use electromagnetic spectra to detect existence and properties of distant planets, ...
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1answer
31 views

Beamsize in radio/microwave observations

In radio/microwave observations, I understand the beamsize is the response of the telescope to a point source - effectively, the telescope's resolution. Now, the Planck satellite (par exemple) ...
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2answers
195 views

Is the angular resolution of a telescope irrespective of used eye-piece?

Suppose a telescope has aperture $D = 20$ cm. The angular resolution of such telescope, according to the Rayleigh criterion (if I have understood it correctly), is given by $$\theta = ...
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2answers
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Claim that 30-m class telescopes will have resolution far superior to Hubble: true?

This article makes the claim that the Giant Magellan Telescope (GMT, number 4 in the list) will have resolution 10 times better than that of Hubble, while the Thirty Meter Telescope (TMT, number 3 in ...
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2answers
115 views

Why does radio astronomy offer higher resolution images than optical?

According to this lecture,"Radio astronomy has several advantages over optical astronomy...We can make the highest resolution images, and see things happening on the smallest scales." Why is this? If ...
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1answer
229 views

What is the typical resolving power of the largest optical telescopes?

I'd like to estimate the typical resolving power of the largest optical telescopes. I've calculated the theoretical resolving power of the VLA for 21 cm light, $$R=\frac{\lambda}{B}=\frac{2.1 \times ...
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Is there a cosmic, rather than technological, upper limit to what a telescope can resolve?

Space radio interferometers could have a baseline of millions of kilometers, but is there a point where a larger baseline doesn't improve the resolution anymore because the photons observed are ...
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4answers
6k views

Is the moon only 60 pixels?

In doing research on vision, I have learned that "20/20" vision corresponds to a visual acuity of being able to resolve details 1 arcminute in size, that most people have around 20/15 vision, and that ...
3
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1answer
101 views

Inability of Hubble to clearly resolve nearby celestial objects

The Hubble space telescope performs incredibly detailed and stunning imaging of celestial bodies that are many, many light years away, and yet when it attempts to image objects within our own Solar ...
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2answers
669 views

How does a telescope measure parallax angle?

I know how stars' distances are measured by using parallax, but I want to know how the actual telescope measures the parallax angle. Any helpful links/ explanations are needed.
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488 views

How does angular resolution of a telescope translate to its parallax precision?

We can often read in the scientific and also more casual reader literature and articles about the angular resolution of various telescopes and other optical equipment, be it ground based or onboard ...