Questions tagged [magnetic-field]

Questions regarding magnetic fields.

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How do neutron stars maintain inhomogeneous surfaces and migrating "hot spots"? (e.g. SGR 1830-0645)

News item NASA's NICER Tracks a Magnetar's Hot Spots and Phys.org's Properties of magnetar SGR 1830−0645 inspected with NICER reference the January 14 2022 arXiv Pulse Peak Migration during the ...
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15 votes
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Has a magnetic field flip of a distant star ever been measured?

The magnetic field of the Sun flips during each solar cycle, with the flip occurring when sunspot cycle is near its maximum. Levels of solar radiation and ejection of solar material, the number and ...
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Could a magnetosphere be created for Venus by recreated by spinning-up the planet to a 24 hour day?

If Venus in it is current state, started rotating at the same rate as Earths 24hrs rotation, would it develop a magnetic field of roughly the same strength as Earth's? If so, would that help in any ...
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2 votes
1 answer
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Why would a black hole's magnetic hair being short-lived not violate the no-hair conjecture, but long-lived hair would? How long is "long-lived"?

Phys.org's Magnetic 'balding' of black holes saves general relativity prediction says: There is a potentially hairy threat to the conjecture, though. Black holes can be born with a strong magnetic ...
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5 votes
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Strength of the relationship between very large solar flares, coronal mass ejections, and solar proton events?

In the years 774-775 and 993-994, there were large peaks in Earth's atmospheric radiocarbon (14C) concentration. While the cause was initially disputed, Mekhaldi et al.'s 2015 study of annually ...
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How big is the Lorentz force on the Sun?

The LOFAR observations have made an estimate of the magnetic field of the Milky Way. The value in our region is very small. About 1/1000 of the Earth magnetic field. The Earth and the Sun move at a ...
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2 votes
1 answer
291 views

What are Ellerman bombs and how can we identify them?

Have you ever heard about Ellerman bombs? Spaceweather.com talks about them on their news page. You could see some of them around sunspot AR2835: Ellerman bombs are magnetic explosions about one-...
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How big is the energy content of the magnetic field of the Milky Way?

Galaxies have associated magnetic fields. So does the Sun and so does the Earth. In the case of the Earth and Sun it seems clear that the energy content of the magnetic fields is much less than their ...
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What does it mean that a black hole has a magnetic field?

Black holes have a magnetic field around them. What does this mean for the interior of the holes? That a net electric charge is "flowing in one direction?" Or at least a net current was ...
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5 votes
1 answer
410 views

How big is the galactic magnetic field in the solar system and how can we measure it?

The Milky Way has an associated magnetic field. But how big is it influence in the solar system and can we measure it? I mean, when measuring, how can we make the distinction between the field of the ...
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2 votes
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What is the sun's maximum influence on a magnetic object?

How much magnetic repulsion could the sun's magnetic field produce on an magnetic object? Consider the object is ideal: It could be flat, to create more resistance, balanced, to stay on the opposing ...
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12 votes
1 answer
3k views

Why do sunspot rise in number "precisely" every eleven years?

Every eleven years (more or less precisely) sunspots are seen to rise in numbers. The magnetic field of the sun changes polarity over eleven years and this is the reason the number of spots can vary. ...
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1 answer
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Why is the 11 yr sunspot cycle less predictable recently?

I quoted from a similar question on solar minima and maxima. "...I guess the jury is still out, but this is quite "fringe" material. The solar cycle is certainly thought to be a product ...
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6 votes
1 answer
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Why is the magnetic axis of Uranus and Neptune off center?

It(Uranus) rotates on its side, tilted almost 98 degrees from the plane of its orbit around the sun. The axis of its magnetic field is tilted too, at a 59-degree angle from the rotational axis. The ...
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3 votes
2 answers
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How massive does a moon have to be to have a stable magnetic field?

Is there a minimum mass or other minimum properties necessary for a body to have a strong, stable dynamo to create a magnetic field conducive for life? For example, would it be possible for Titan to ...
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2 votes
2 answers
217 views

Would it be possible to detect a magnetic field around an exoplanet?

Of course, we can't fly a magnetometer next to an exoplanet to measure the magnetic field, but might it be possible to find indirect evidence (e.g. polar auroras) of a magnetic field generated by an ...
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4 votes
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Why is solar corona in visible light filamentary?

There is a video on YouTube (unfortunately in Czech) where Miloslav Druckmüller talks about structure of the solar corona in visible light. He explains that the filaments, clearly visible on his ...
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1 vote
1 answer
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What about the magnetic field strength inside of an old accreting neutron star?

As the magnetic field strength outside an old accreting neutron star is thought to be small (about $10^8-10^{10}$ Gauss), what about it inside the star? Because of the superconductivity and ...
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How would Earth's magnetic field change if the outer core was solid?

A widely accepted theory for how the Earth's magnetic field is generated is the dynamo theory. Dynamo theory describes how molten magma convection currents containing metal are locally spun the same ...
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4 votes
1 answer
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Why does a right-handed circular polarized wave get lagged when going through ionized plasma?

I have a question related to Faraday rotation. In Abigail Polin's Faraday rotation video I have seen that a linearly polarized wave can be decomposed in a left-handed circular wave and a right-handed ...
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4 votes
2 answers
435 views

What would Aurora look like if no magnetic field was present around the Earth?

The greatest part of the Earth is protected from the Solar wind by its magnetic field. This field makes the wind particles (mainly protons and electrons) the beauty of Aurora appear. Suppose the ...
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2 votes
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How would Aurora look like if no magnetic field was there to protect the Earth? [duplicate]

The greatest part of the Earth is protected from the Solar wind by its magnetic field. This field makes the wind particles (mainly protons and electrons) the beauty of Aurora appear. Suppose the ...
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5 votes
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How is angular momentum transferred between a neutron star and its accretion disk?

Accreting neutron stars can either gain or loose angular momentum via interaction with their accretion disks. This leads to either spin-up or spin-down. Which of the two is the case, depends on the ...
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How do magnetic fields mess with astronomers' observations?

Does anyone else watch 'Dr. Becky' on YouTube? Her March 'Night Sky News' video, subtitled 'The biggest black hole burp, a wobbly Milky Way & Betelgeuse is brighter' says that... "Dust and ...
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4 votes
1 answer
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Why is our heliosphere an asymmetric croissant shape?

The big, recent astronomy news about our heliosphere's asymmetric croissant shape has me confused.... Some articles mention the influence on our solar system's outermost boundary of very hot cations, ...
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2 votes
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Is the magnetic field strength of a star predictable from mass, composition, age and angular momentum alone?

This answer to Which stellar properties can we describe as “first principles” in which we can derive the rest? contains an intriguing bit: That states that composition and mass are the two key ...
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10 votes
1 answer
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Would Europa be an ocean planet if it were in the habitable zone?

If a Europa-like body were in the Sun's habitable zone, let's say in an orbit between Earth and Mars, would the body become and remain a water ocean planet? In the habitable zone, the Sun would warm ...
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3 votes
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Which moons do have neutrospheres?

Or in other words: which moons do have ionospheres but not surface-bound ones? The space beneath an ionosphere is called a neutrosphere. I only know of Titan. I know that the Galilean moons and Triton ...
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2 votes
1 answer
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What do these statements about interstellar magnetic fields really mean?

Quanta Magazine's The Hidden Magnetic Universe Begins to Come Into View is a fascinating review of a rapidly evolving field in astronomy. It contains some statements that I feel are important to ...
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1 vote
1 answer
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Has the permittivity or the permeability of space been measured in a gravitational well?

Technically one might say yes since earth is gravitational well. However I am looking for more data points. For example, in deep space where voyager might be at the Lagrange points of massive bodies ...
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16 votes
2 answers
1k views

Are there neutron stars whose magnetic axis and rotating axis are the same, and if so what will happen?

I know that there's probably a higher chance of having a neutron star that has its magnetic axis inclined to the rotational axis rather than having it perfectly aligned. If they are not aligned, the ...
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3 votes
0 answers
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Would magnetic reversals on Ganymede affect radiation levels at the surface?

Currently the intrinsic magnetic field of Ganymede is anti-aligned with respect to the Jovian magnetic field. If this situation changed to become aligned, either due to magnetic reversals of the ...
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1 vote
2 answers
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Is it possible to revive the Mars geodynamo? [closed]

I’ve done a bit of reading and have found multiple theories suggesting how the Mars geodynamo stopped fully working. This site suggests that one possibility could be volcanic activity ejecting water ...
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1 vote
0 answers
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Energy of a charged particle in the magnetosphere

I asked this question on physics.stackexchange, but as it is a space/magnetosphere question maybe someone here can help me out: Taking the earth as an idealized dipole and the E field from the sun ...
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4 votes
1 answer
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What are the sources of antimatter particles in the magnetosphere?

The PAMELA instrument detected antimatter particles in the Earth's magnetosphere. What are the sources of these particles? The answer to Source of high energy cosmic particles outlines the sources ...
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2 votes
2 answers
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In practice, can very high magnetic fields significantly alter the dynamics of an astronomical-scale bodies?

The direct effect of magnetic fields on the dynamics (as in the movements, trajectories etc of the bodies themselves, rather than lower-level phenomena like stellar winds and atmospheric degradation) ...
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3 votes
0 answers
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Superconducting space dust; what transient fields could induce persistent current loops?

Science Alert's Superconductivity Has Been Discovered in Meteorites For The First Time quotes from Superconductivity found in meteorites (Wampler et al. PNAS March 23, 2020) The paper describes the ...
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1 vote
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Magneto tail effect on the other planet in a binary planet system

Let's say there are 2 earth sized planets orbiting each other around 750,000km apart and at a distance of roughly 1.2 AU from a sunlike star with a mass of 1.105 solar masses. Since they are binary, ...
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2 votes
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What influence does the Interplanetary Magnetic Field have on Planetary Orbits?

CONTEXT The equation $F_D=\frac{GMm}{D^2}$ is a standard equation in Newtonian gravitation. It describes the centripetal force exerted, by a source mass$M$, on a target particle of mass $m$ located ...
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Would exoplanets like those of Kepler-70 possess magnetic fields?

The B-type subdwarf, Kepler-70 (aka KIC 5807616) is believed to have two planets orbiting it, at average distances 0.006 AU and 0.0076 AU (source). Due to their proximity to their parent star, they ...
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2 votes
1 answer
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Does Earth's magnetic field become stronger when a solar flare hits?

This curiosity arises as follows: when ejecta from a strong solar flare hits Earth, will the Earth somehow counter its impact with a stronger magnetic field. Or, earth's magnetic field as limited ...
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9 votes
2 answers
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Why is the Earth's magnetic field stronger than its neighbors?

[Edited] I've learned that the Earth's core is hot due to decay of radioactive elements, causing the liquid part of the core to stay liquid. This was stated as an explanation to why the Earth has a ...
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5 votes
1 answer
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Why does the solar wind switch to flowing straight by the time it reaches Earth?

Between 02:01 and 02:29 the new NASA Goddard video 5 New Discoveries from NASA's Parker Solar Probe explains finding # 4, A ...
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2 votes
1 answer
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Why do the magnetic field lines of the earth go from south pole to north pole?

I saw these figures and could not get why the magnetic field lines are not pointing from the north pole towards the south pole but they do the opposite. Or also this picture which is about magnetic ...
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4 votes
1 answer
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What exactly are infrared dark clouds and what is the significance of the orientation of their magnetic fields?

In the video Why NASA's SOFIA Telescope On A Plane is "Perfectly Balanced" after about 10:04 SOFIA associate director James Jackson says: We have a ...
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4 votes
1 answer
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Earth's magnetic field vs. refrigerator magnet

According to this article: The Earth's field ranges between approximately 25,000 and 65,000 nT (0.25–0.65 G). By comparison, a strong refrigerator magnet has a field of about 10,000,000 ...
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2 answers
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Does the magnetic field of earth restore?

The magnetic field of earth protects us from solar wind as we know it, but after the solar wind interacts our magnetic field. Does the magnetic field of earth restore after it deflects the solar ...
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0 votes
1 answer
172 views

When and where are we exposed to most cosmic radiation?

I understand the mechanical dynamics of being faced away from the Sun at night, having a lower altitude, not being in the weak points at the poles in the atmosphere, being in a valley and others ...
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0 votes
1 answer
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The sun's SOLAR WIND VS MAGNETAR

As we know magnetars have strong magnetic field but what if we swap earth with a magnetar and the sun will released a solar wind. Is the magnetar affected by the solar wind or not ?
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-4 votes
1 answer
222 views

What is the time dilation less a magnetic field?

Does time dilation drop off like a gravity or does resemble a magnetic field model? Could a smaller body with a magnetic field have more time dilation then a larger body without and to what degree?
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