Questions tagged [plasma-physics]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
64
votes
2answers
11k views

Is it dark inside the Sun?

This might sound like a strange question, but something got me thinking about it recently. The opacity of plasma in stellar interiors can get quite high, making for shorter free-paths for photons. In ...
1
vote
1answer
46 views

Do free protons and neutrons absorb much radiation? To affect astronomers' observations? If so, at what wavelength(s)?

In a plasma, or wherever, do the completely ionized nuclei commonly absorb much EM radiation? Or any free neutrons or protons? Can astronomers detect this? Enough so that astronomers take it into ...
0
votes
0answers
17 views

How to determine arrival time delay given dispersion measure?

In an online textbook, the following formula is given to calculate the arrival time delay between two frequencies, $v_1, v_2$ in a dispersed radio pulse: $$t_1 - t_2 = 4.15 \cdot DM [(v_1/\text{GHz})^{...
7
votes
1answer
688 views

Blue color of ion (plasma) comet tails

What exactly is the cause of blue light of ion (plasma) tails of comets? Somewhere I have read that the source of blue light are CO+ ions which has just acquired the missing electron and became ...
1
vote
0answers
31 views

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 ...
1
vote
0answers
57 views

Does plasma recombination in the solar wind happen to any significant or measurable degree?

Comments below this answer to Why does the Solar Wind consist of charged particles? have led me to ask the following: Question: Does plasma recombination in the solar wind happen to any significant ...
0
votes
0answers
150 views

Has the plasma amplification of electromagnetic waves in solar type-III bursts (or otherwise in stars) been explored further?

This answer to the SciFi SE question In the novel The Three-Body Problem, does the Sun's amplification of radio transmissions have a scientific basis? cites a 1995 paper published in Chinese Astronomy ...
6
votes
1answer
72 views

Voyager 1 and 2 detected a 20-fold increase in plasma density, significantly different refractive index?

As reported by Nature.com, Voyager 1 and 2 detected a 20-fold increase in plasma density going from the heliosphere out to interstellar space. Does that 20-fold difference in density imply a ...
1
vote
0answers
28 views

If interstellar medium was dense plasma and light slowed down, would things appear to move slower far away?

Voyager 2 recently left the solar system and registered an increase in plasma density. If light moved slower in this dense plasma, would it appear like events in other solar systems played out slower ...
3
votes
0answers
24 views

What is the “radiation sound speed” inside an accretion column?

I was trying to read "A New Two-fluid Radiation-hydrodynamical Model for X-Ray Pulsar Accretion Columns" and its follow-up paper both by West et al. and came across a quantity called "radiation sound ...
6
votes
2answers
87 views

How far can you see in solar plasma at just under 1 solar radius?

I was trying to compose an answer to this question here, about touching the surface of a star, and I was going to mention that the popular depiction of the sun's surface as 'basically lava' (as ...
3
votes
3answers
237 views

Will the Sun's solar wind push a permanent magnet out of our solar system?

If you were place a strong permanent magnet into the solar wind, like a 1 inch cube neodymium magnet, would the charged particles of the solar wind colliding with the magnet's magnetic field push the ...
2
votes
1answer
114 views

Just after the Big Bang, was the space, in its entirety, filled with Hot gas?

After the Big bang occurred, was the space filled with hot gas totally? If there's any problem in my question please inform me. Thanks!
85
votes
6answers
7k views

Does the Sun rotate?

The planets rotate as an after effect of their creation, the dust clouds that compressed span as they did so and the inertia has kept it rotating ever since. It's fairly easy to prove that planetary ...
-1
votes
1answer
170 views

Could there be massive charged “rivers” in interstellar space?

Some suggest that there might be currents of charged particles moving at 0.98c in interstellar space. Since this is tainted by association with the crack “Electric Universe” cosmology, my first ...
7
votes
1answer
165 views

Are sunspots vertically displaced from the surrounding photospheric plasma?

While reading a paper on the helioseismology of sunspots (Cameron, et al.), very brief reference is made to the "vertical displacement of a blob of plasma." This caused me to wonder if the emissive ...
4
votes
1answer
78 views

Population of excited H levels in a Strömgren Sphere

In chapter 2.2 of Astrophysics of Gaseous Nebulae and AGN Ostriker and Ferland claim that, as far as ionization is concerned, one can assume all atoms to be in the ground state in a Strömgren Sphere ...
5
votes
1answer
706 views

What is the temperature of the solar atmosphere (the corona) and how is it measured?

The temperature of the Sun's atmosphere, also referred to as the solar corona, is known to be hot even hotter than the Sun's surface. What is its temperature and how is it measured? How does it ...
2
votes
1answer
340 views

Do some ELF (Extremely low frequency) radio waves pass the atmosphere

...reach Earth surface and then are reflected passing the atmosphere again to reach outer space? And once in outer space can they travel indefinetely in it or the interplabetary plasma would stop them?...
5
votes
2answers
130 views

What triggers solar flares?

The sun is a big ball of hot plasma which contains free electrons. However, how does the absence of metallic elements in the sun generate the magnetic field to orchestrate these free electrons to ...
-1
votes
2answers
243 views

Nuetrino interaction with plasma and electromagnetism [closed]

Following question enter link description here After watching the Thunderbolt Project on Youtube I have a very very very fresh perspective on the universe - the electric universe. From the electric ...
9
votes
2answers
204 views

On analogies between gas and stellar systems

Analogies between (typically) ideal gas and stellar systems are not only intuitively valid to some extent, but have been established and used in the studies of stellar clusters and galactic systems, ...
15
votes
1answer
273 views

Stars at near break-up rotation rates

Accretion discs are ubiquitous in astrophisics. As a direct corollary, they are important for the following question. Consider the following model, representing one of the most simple models for ...