All Questions
Tagged with astronomy electromagnetism
24
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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 ...
- 1,940
1
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32
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What creates the Global Dipole Magnetic Field in the Sun?
I understand that the Sun undergoes convection and with rotation, the convective cells have a helical motion because of the Coriolis Force. My confusion comes from the fact that via the right-hand ...
- 11
2
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1
answer
92
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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 ...
- 31
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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 ...
- 93
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3
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75
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Can a detector fail to detect a wave of electromagnetic radiation because the wave's amplitude is at or near its minimum?
If a very brief wave (perhaps a single photon, or maybe a soliton?) is at its minimum (a 'node') when it encounters a detector, would it still be detected?
- 4,509
2
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1
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97
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Astronomical objects that should have magnetic bubbles similar to those found by the Voyager probe at the edge of our solar system
I've known about the existence of magnetic bubbles at Solar System's edge from a video edited by NASA from an official channel of YouTube, I refer [1] (as explicitly stated in the title, it was a ...
1
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2
answers
145
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Is dark matter paramagnetic/diamagnetic?
From my understanding, constrains on the interaction of dark matter with electromagnetic fields comes from the lack of scattering/absorption/emission of light.
But, do we know anything of its DC ...
- 914
2
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2
answers
139
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Collision or impact of a gamma-ray burst against the magnetic bubbles at Solar System's edge
I'm going to ask* about what should be the effect/interaction, if any, when a gamma-ray burst crashes or hits against the magnetic bubbles at Solar System's edge. These magnetic bubbles are explained ...
5
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1
answer
460
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Measuring lowest photon energy
If I wanted to buy a receiver that measures the energy of incoming photons, what is, not theoretically, nowadays the lowest energy that can be measured (in joule)?
- 421
2
votes
1
answer
496
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How do I transform flux density into temperature?
I have flux density data from Planck mission (in Jy) - measure in a certain frequency - and I would like to transform it to temperature data (Kelvin). I'm not sure if I should use Stefan Boltzmann's ...
- 301
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94
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Query about the ion tail of a comet
I understand that the solid gas coating the nucleus of a comet is melted and that this gas is ionised by the UV rays from the sun. This makes the gas particles charged.
What I dont understand is why ...
- 1,525
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1
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54
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Can someone confirm my understanding of the photo metric system?
So from my understanding there exists a photometric system in Astronomy, such that a particular letter such as I corresponds to the I band (with I meaning infrared), and corresponds with 806nm ...
- 191
2
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1
answer
1k
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Physical meaning of Fourier transform of an electric field?
If I take the Fourier transform of the autocorrelation of a signal in time, I will get the power spectral density.
But if I just have a signal of the electric field, $E(t)$, in time, then the ...
- 649
2
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0
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91
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World's Largest Radio Telesope : How accurately does it need to be figured?
In Guizhou Province, China, the worlds largest radio telescope is almost complete, measuring 500 metres across.
I am aware that todays largest optical telescope require very accurate figuring and ...
user108787
3
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1
answer
186
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Why don't stars re-emit the photons they absorb, thus restoring a continuous emission spectrum?
If you shine white light through a gas, electrons can absorb sufficiently energetic photons to reach higher excited states. This produces gaps in the spectrum and it's how Helium was discovered. So ...
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