Unanswered Questions
318 questions with no upvoted or accepted answers
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Spatial wind speed distribution on Mars using dune shapes?
As a fan of exometeorology (the study of atmospheres of other planets), I scanned through a whitepaper Measuring Mars Atmospheric Winds from Orbit which says
Measurements of Mars
atmospheric winds ...
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8
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Is there a standard deconvolution procedure to remove JWST's diffraction pattern yet? If so, would Arp 220 be a good candidate on which to try it?
Source: Webb captures the spectacular galactic merger Arp 220
Shining like a brilliant beacon amidst a sea of galaxies, Arp 220 lights up the night sky in this view from the NASA/ESA/CSA James Webb ...
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7
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Can terrestrial infrared telescopes see through clouds or haze, sometimes at least?
My answer to Could UV-A imaging sensor reasonably see a total eclipse in progress through clouds? suggests that while clouds blocking visible light observation of the (partially) eclipsed solar disk ...
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Angular resolution of naked eye at night; type of vision used
It appears that most sources quote the angular resolution of the eye as 1', regardless of day and night.
For instance,
Naked eye
Seconds of Arc and the Unaided Eye
However, the following websites give ...
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What's the largest angle that light has been "seen to bend" by gravity? (of one object by a separate object)
Gravitational lensing is everywhere! because it falls off so slowly with $r$:
$$\Delta \phi \approx \frac{4GM}{c^2r_0}.$$
That's the first order term. For a nice derivation see Viktor Toth's The ...
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6
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194
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What are the pros and cons of different types of echelle spectrograph cross-dispersers?
Echelle spectrographs, operating at high resolving power, typically consist of an echelle grating with a low numbers of lines/mm, used with high diffraction orders (often $n=$50-100). To separate the ...
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6
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How was the axial tilt of planets measured?
https://en.wikipedia.org/wiki/Axial_tilt#Solar_System_bodies gives the axial tilt of all planets with two decimal precision, but how and when were they measured so precisely ?
I guess it's "easy&...
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6
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206
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How far have stars been seen beyond the center of the Milky Way?
What lies near the center of the galaxy is of great interest and in recent times the motion of dozen(s) of stars at the center of our galaxy orbiting around Sgr A* have been measured in great detail. ...
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6
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Need help understanding stellar spectroscopy data from ESO
The European Southern Observatory webpage has a web page that has tabular spectrogram data from A. J. Pickles, University of Hawaii. There are over 130 .dat files there. Each one represents a ...
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6
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Do narrow lines in the spectra of O- and B- type stars always indicate magnetic fields?
I was reading a paper on the differential emission measures of a set of hot O- and B- type stars. As the authors discuss in Section 3 (page 959), two stars, $\tau$ Sco and $\theta^1$ Ori C, have ...
CommunityBot
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6
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1
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510
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Could non-supernova carbon, oxygen, or silicon flashes be observed?
I was reading about the helium flash, the short but sudden onset of helium fusion in certain red giant stars. As I understand, the upper (nondegenerate) layers of the star absorb the energy as they ...
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5
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Is there a noob-friendly website/app for tracking a astronomical body's apparent movement over time?
As I walk home along my road most nights in winter, I see the Moon and one-or-more planets.
Unsurprisingly, over the last 2 months, if it's been the same planet and it (and the Moon) has been in ...
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513
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How far away must galaxies be before current telescopes can no longer measure how quickly they are rotating around one another or internally?
What is the distance limit and does it depend on the size of the galaxy and on noise and interference from gas clouds and our own Milky Way?
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Positional astronomy - Speed of the sun in sky
Let $\vec{r}$ be the position of the Sun in the sky, from Earth. How could I estimate the magnitude of $d\vec{r}/dt$, to measure the rate of change in time of the arc it traces? I suppose it would be ...
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A new (radio) neutrino telescope in Greenland?
I just stumbled upon ScienceMag news from July 14th, 2021 which says:
By placing hundreds of radio antennas on the ice surface and dozens of meters below it, they hope to trap elusive particles known ...
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