All Questions
Tagged with astronomy astrophysics
469
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What is emission line ratio?
As the header stated, what exactly is the 'emission line ratio'? Like, [O III]/Hβ or [Ne V]/[Ne II]. Recently I've been reading some research papers in astronomy and astrophysics pertaining to ...
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What is the function that demonstrates a planetary transit light curve given a planet's projected distance from its star?
Last night I was measuring the brightness of a Hot-Jupiter parent star to try and isolate the transit light curve (specifically Tres-2b). I have been wondering how to obtain the function that ...
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Using helioseismology what are the equations astrophysicists use to determine the age of the Sun?
Astrophysicists talk about solar models when determining parameters of the Sun. But these models must be built from equations. When explaining to the general public what these equations are would be ...
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Does the Kardashev Scale have any practical application?
As the question states: are there any practical applications of the Kardashev Scale?
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Magnetic tubes or magnetic field lines around a black hole?
A picture is worth thousand words:
Magnetic field lines, unlike magnetic tubes, have a continuous distribution. Recent pictures of black hole magnetic structure show tubes. Is there a model that ...
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Galaxy harassment; flyby encounter (tidal interaction)
This following image is from the paper https://adsabs.harvard.edu/pdf/1978AJ.....83..219R#page=4
It shows the path of a flyby encounter of NGC 3627 (M66) with the galaxy NGC 3628 (the Hamburger galaxy)...
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The expectation value of intersecting particles
If I have a light beam (a straight line)
it goes through a box of dust, which has travelling length $l$, dust molecule cross section $\sigma$, dust number density $n$.
how to calculate the expectation ...
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(Astrophysics) How to calculate photons detected by a radiometer over a period of 10 seconds?
I know the Flux (calculated from flux density), and frequency but i dont think I have area.
This is the question, it is part d and ive done all other parts:
"Consider three widely separated ...
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Is there a galactic "goldilocks" region in the galaxy
I'm wondering if there's a region where the star density in the galaxy create the conditions in outer space where the galactic temperature is between 0 and 200°F. This may cause a ring shaped where ...
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Einstein's derivation of stellar aberration formula: replacing the direction of the ray with a difference in angles justified?
I was going through the translation of Einstein's 1905 paper "On the Electrodynamics of Moving Bodies"(See https://einsteinpapers.press.princeton.edu/vol2-trans/175). In deriving the stellar ...
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Is there any tools for observing magnetic fields and forces of black holes and galaxies?
I want to know about how we can find magnetic forces and fields in space around stars, planets, galaxies, pulsars especially pulsars. How (by what means) did determine magnetic fields around a pulsar?
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Is cosmological redshift associated with recession velocity when the light left or when it arrived?
Is the cosmological redshift $z$ associated with the recession velocity when the light left, when it arrived, or something in-between?
user300520
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Does the Earth's magnetic field lag behind the Earth as Earth orbits the sun?
I imagine that when the earth orbits the sun, the earth's magnetic field is also subject to the sun's gravity, since photons and light are subject to gravity. As a result, the magnetic field does not ...
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Measured Value of Hubble's Constant [duplicate]
As we know, Hubble's Constant is not exactly a constant, but its value varies with time. However, we also speak of measuring its present-day value. The measurements by cosmic distance ladder would ...
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Is differential number density the same as flux density?
I'm trying to convert the differential number density of photons to luminosity (using slide 17 of https://www.astro.rug.nl/~sctrager/teaching/OA/Photons.pdf) and ...
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