Unanswered Questions
349 questions with no upvoted or accepted answers
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How does the Astronomical Twilight depend on the night length or the day length?
Some references say that the Astronomical Twilight starts at the last 1/8th of the night length, so it is long in Winter and short in Summer;
But by using the 18 angle (sun elevation below the ...
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What is the highest redshift a galaxy with a known stellar mass can be observed?
As part of my research, I would need the following information which it seems I cannot find it in literature. I would like to know what are the highest redshifts at which $10^{7}$, $10^{8}$, and $10^{...
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How can one determine the declination range of stars visible for a certain amount of time above a specific airmass at a certain location?
Let's assume you want to observe stars at Kitt Peak (32 degrees North) at an airmass above 2, for 2 hours (30 degrees of Earth rotation).
My attempt:
The angle between the zenith and celestial ...
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Planets not visible
I have recently purchased an Orion AstroView 90mm Equatorial Refractor telescope, also this is my first time having a telescope. The telescope came with a 25mm and a 10mm eyepiece, I also bought a ...
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