Questions tagged [dust]

Questions about particulate matter found between stars, not to be confused with gas or ionised plasma. For planetary dust storms, use [dust-storm].

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Why did the dust between the planets disappear during the birth of the solar system?

I'm catching up on my childhood mistakes. One of them was the "nuclear flash", the enormous explosion when the sun ignited. Apparently, this did not happen as the ignition of the sun was a ...
Dominique's user avatar
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2 votes
1 answer
266 views

The Poynting Robertson Effect

In the Poynting Robertson effect, it says in general, the Poynting Robertson effect is caused by the fact that objects like dust re-emit the light they absorb. Is that correct? Is this effect weak? ...
A Curious Mind 's user avatar
1 vote
0 answers
35 views

What is value of charge by mass ratio (q/m) for a spherical micro charged particle with surface potential 6 volts in S.I units and in e/amu units?

In Liu and Ip (2014),The Astrophysical Journal, 786:34 (8pp), the value of q/m is derived as follows : "for a dust grain with radius 'a', from $\phi = \frac{4\pi q}{\varepsilon_0 a}$ we have $\...
Lunthang Peter's user avatar
1 vote
0 answers
77 views

How did the Cassiopeia A Supernova go unobserved?

The Cassiopeia A was caused by a Supernova estimated to have taken place around the late 17th century. The Remnant's declination means that it would be Circumpolar for anyone north of 30N, and it's ...
blademan9999's user avatar
6 votes
2 answers
88 views

Meteors arriving to a planet's atmosphere?

Imagine a planet with little or no wind activity or precipitation, but that still has an atmosphere. When a meteoroid reaches the atmosphere and burns, it converts into dust and gas. Does this gas and ...
vengaq's user avatar
  • 867
5 votes
0 answers
90 views

Are dust-dust collisions necessary to explain Kordylewski clouds at Earth-Moon L4/5? Aren't the cross-sections, number density timescales too small?

The recent question Can dark matter accumulate at Lagrange points? mentions Kordylewski clouds and that article begins: Kordylewski clouds are large concentrations of dust that exist at the L4 and L5 ...
uhoh's user avatar
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1 vote
1 answer
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How do they see BOTH "anomalously cool with a significant mid-IR excess" rather than one or the other? (SN 2023ixf progenitor)

The abstract of the arXiv preprint SN 2023ixf in Messier 101: A Variable Red Supergiant as the Progenitor Candidate to a Type II Supernova (itself recently "discovered" in the observatory) ...
uhoh's user avatar
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4 votes
1 answer
337 views

How does the number of CMB photons vary with time?

When the CMB temperature is calculated does it take into account photons absorbed by gas clouds and dust over billions of years?
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1 vote
2 answers
215 views

What would the night sky look like after 200 years?

It is research for a book I am writing. The year is 2200. Assume the volume of items in orbit has increased dramatically from today’s numbers. We go to war and blowup all the satellites. Four hundred ...
Ken's user avatar
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2 votes
1 answer
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The path of a particle in planet's magnetic field doesn't not seem to change with the charge of the particle. Can someone please check what is wrong?

I am trying to plot the path of a charged particle in a planet's magnetic field. For positive and negative charge (β=charge/mass) different solutions/paths are expected. But,I got the same solution (...
Lunthang Peter's user avatar
9 votes
3 answers
2k views

Does the existence of hydrogen in the universe create an obscuration effect similar to the way air does at great distances?

I've had this question for a while. I understand the universe is full of "dust". I am also aware of the fact that there is an average measure of particle density in the universe. I am ...
Rabbi Kaii's user avatar
7 votes
2 answers
153 views

How much cosmic dust is there in the asteroid belt?

I've tried looking on google but I've found nothing that directly answers my question. I've found that around Earth there is around 1000 grains in every cubic kilometre, but I'd assume that there is ...
Ichthys King's user avatar
6 votes
0 answers
92 views

Cooling timescale for an interstellar dust grain

I would like to estimate the cooling timescale for an interstellar dust grain, starting at 200K, down to 100 K. The equation I have come up with is: $\displaystyle t_{cooling} = \frac{mC\Delta T}{Q_{...
lucas's user avatar
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9 votes
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Star formation - Is it just gas accumulation or does dust also play a role?

Inspired by the question, Are heavy elements equally distributed throughout the Solar System?, with a little further inspiration from this one as well, Star formation analogy, particularly the answer ...
Fred's user avatar
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7 votes
2 answers
722 views

Why does dust affect UV light more severe than it affects X-rays?

My supervisor told me that the UV photons emitted from AGN are heavily affected by ISM (dust extinction), but not X-rays, as described in Extinction - a powerful discriminator of dust size. Since X-...
Jack the Ranger's user avatar
9 votes
2 answers
233 views

How much mass does the Sun gain from the Poynting-Robertson effect?

I understand that the Poynting–Robertson effect describes solar radiation-induced drag on certain sized dust particles, causes them to lose orbital angular momentum and eventually fall into the Sun. ...
Brooks Nelson's user avatar
17 votes
1 answer
2k views

How could low-gravity dust in the early solar system have formed hard stones?

I wonder how very low-gravity dust could make bind together and make hard and dense stones that later on will merge together and make some of the planets? I read some meteorites as hard as a hard ...
Mehdi Abbassi's user avatar
5 votes
0 answers
49 views

Extract surface density profile from a temperature profile?

I have a protoplanetary disk model which outputs a temperature vs. radius profile, based on radiative transfer. Looks something like this... One of the inputs to the model is the surface density ...
lucas's user avatar
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1 vote
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what is the difference between Composite Stellar Population and Galaxy Spectral Energy Distribution?

I am reading Conroy et al. (2013), an extensive review on Stellar Population Synthesis technique, and I really can't get the difference between Composite Stellar Population and Spectral Energy ...
fslack's user avatar
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3 votes
1 answer
451 views

How to estimate the temperature of an interplanetary dust grain?

I'm trying to solve this task: Estimate the equilibrium temperature of an interplanetary spherical dust grain if it is located at a distance of 3 AU. from the Sun, and the substance of the dust ...
ALiCe P.'s user avatar
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1 vote
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Power law of object mass in Milky way

Red dwarfs are more common than larger stars. Does this trend continue to smaller objects? If you take every "condensed object" from dust grains through asteroids, planets, and stars in the ...
Kevin Kostlan's user avatar
2 votes
1 answer
155 views

If Betelgeuse dimmed because of dust, what became of the dust?

This question started as a clarification request of a question from Glorfindel, answered at least in part by James K, and I realized it would probably be best as a stand-alone question. The most ...
JohnHunt's user avatar
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1 vote
1 answer
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What is the meaning of grain opacity and why does it affect the formation time of gas giants?

While doing research for my presentation on the formation of gas giants, more specifically the "core-accretion model", I have been stumbling across the term "grain opacity" and don'...
Julian Saling's user avatar
2 votes
1 answer
64 views

Is scattering efficiency of dust related to albedo?

I know that the scattering cross-sections of dust in comets depend on the scattering efficiency. A higher scattering efficiency leads to an increase in brightness. Therefore, does it mean that this ...
prody's user avatar
  • 88
6 votes
2 answers
1k views

Interstellar Dust properties

While practicing for an upcoming examination, I ran into this problem: Which of the following best describes dust grains in the interstellar medium: They are a few hundred nanometers in size (size ...
Kraftsman's user avatar
  • 163
4 votes
1 answer
241 views

How many solar system objects that can really qualify as a KBO are likely to enter Pluto's Hill sphere each day?

A comment below Which celestial body is able to come closest to Pluto? says that Technically, many, many small Kuiper belt objects enter Pluto's Hill Sphere (or sphere of influence SOI) every day. ...
uhoh's user avatar
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8 votes
1 answer
433 views

Could rocks from Earth have reached the Kuiper belt, or Neptune at least? If so, how?

This answer (currently edit 3) to How certain are we that we have not sent life to other planets/moons? begins: First of all, rocks from Earth are probably just about everywhere in the Solar System. ...
uhoh's user avatar
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3 votes
1 answer
314 views

How do we know that the discovered M87 black hole isn't just a star surrounded by a dust disk?

To an untrained eye like mine, pictures of stars surrounded by dust discs look very much similar to the picture of the M87 black hole. Here are some pictures of these dust discs: And here is a ...
Beliod's user avatar
  • 63
38 votes
2 answers
6k views

How can comets have tails if there's no air resistance in space?

I understand that solar radiation causes material to vaporize out of a comet into dust but why does the dust then trail behind the comet like a "tail"? Assuming gravity is the only applied force ...
anonemes11's user avatar
3 votes
0 answers
44 views

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 ...
uhoh's user avatar
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11 votes
1 answer
459 views

Was the "green star" event in NGC 3314 ever figured out or named?

from NGC 3314 Variable Object by By Bill Keel (University of Alabama, Tuscaloosa) and Lisa Frattare (Hubble Heritage Project, STScI). The object in question is circled. Comments below this answer led ...
uhoh's user avatar
  • 31.1k
3 votes
1 answer
185 views

Tongue-in-cheek quote on dust extinction

I remember hearing a quote or maybe rather an anecdote about a famous astronomer but I can't recall the exact wording and I also forgot who allegedly said it. Unfortunately, that has thwarted all my ...
user35915's user avatar
  • 301
5 votes
0 answers
447 views

Why does titanium oxide around Betelgeuse produce this particular sawtooth-shaped absorption spectrum?

Betelgeuse Just Isn’t That Cool: Effective Temperature Alone Cannot Explain the Recent Dimming of Betelgeuse suggests that the recent dimming might be caused by increased optical absorption by dust ...
uhoh's user avatar
  • 31.1k
10 votes
1 answer
190 views

Color index B-V of the dimming Betelgeuse

Using AAVSO light curve generator I have plotted V and B magnitudes of Betelgeuse in the past 150 days to see trend of B-V color index. If dust would be the cause of the recent drop in the star ...
Leos Ondra's user avatar
  • 1,074
7 votes
1 answer
1k views

What cluster of stars is this with a "dark donut" to one side?

In the 2011 Sixty Symbols video Spy Satellites (from Deep Sky Videos) after about 01:44 amateur astrophotographer Nik Szymanek shows an image of a cluster of stars ...
uhoh's user avatar
  • 31.1k
0 votes
1 answer
106 views

Are red dwarfs (M dwarfs) known to be strong infrared sources?

If so, why? Are they known to be surrounded by large amounts of dust? Do they typically flare?
user avatar
3 votes
0 answers
72 views

Clarity on dust extinction terms and implementation: $R_V$,$ A_V$, and $E(B-V)$

I have created a model galaxy spectrum using STARBURST99 and want to compare it to an observed spectrum of a particular galaxy. I understand that I need to redden ...
curious_cosmo's user avatar
5 votes
0 answers
72 views

Can anyone explain this odd Galactic dust filament near the LMC?

Perusing the Planck 353 GHz polarisation Aitoff projection I noticed an apparent magnetically driven dust filament rising abruptly from the Galactic ß-field in the Chameleon-Mensa S polar region. It ...
Douglas Bullis's user avatar
12 votes
1 answer
1k views

How did they make a video of the center of the galaxy, and what is it exactly that's flashing there?

The ESA video ESOcast 173: First Successful Test of Einstein’s General Relativity Near Supermassive Black Hole includes a clip of images of stars at the center of our galaxy orbiting around SgrA*, a ...
uhoh's user avatar
  • 31.1k
6 votes
1 answer
147 views

What experiment does this "Tracing the History of Starlight" video try to explain?

The YouTube video Tracing the History of Starlight with NASA's Fermi Mission describes observation by the Fermi gamma ray telescope of EBL (extragalactic background light) gamma rays from 2,000 ...
uhoh's user avatar
  • 31.1k
1 vote
1 answer
139 views

Has "GHz-spinning dust" ever been demonstrated in the laboratory?

This excellent answer to the question What is the physics of the “spinning dust” contribution to Cosmic Microwave Background measurements? includes the figure below which helps show what it was the ...
uhoh's user avatar
  • 31.1k
10 votes
1 answer
284 views

Why is there free magnesium in the ecliptic (if there is) and why would some be orbiting within the ecliptic plane but retrograde?

This answer to the question What direct or indirect observations of dust can one make by eye or with binoculars? mentions Brian May's thesis and it's connection to Zodical Light: Brian May (CBE): In ...
uhoh's user avatar
  • 31.1k
2 votes
2 answers
145 views

What direct or indirect observations of dust can one make by eye or with binoculars?

The solar system and space in general has plenty of dust, and dust has major impacts on observing both visually and in radio astronomy. If I wanted to "see dust" in space, or see its effects, using ...
uhoh's user avatar
  • 31.1k
3 votes
1 answer
226 views

Why doesn't the equipartition theorem disallow spinning dust?

This excellent answer to the question What is the physics of the “spinning dust” contribution to Cosmic Microwave Background measurements? Is well sourced. The abstract of one of the papers there, ...
uhoh's user avatar
  • 31.1k
7 votes
1 answer
354 views

How does V838 Monocerotis look today? Any subsequent light echo images, or is the party over?

This answer to the question V838 Monocerotis “light-echo” images morphed into nice video, but why so few original images? contains the following information below. There are other answers and more ...
uhoh's user avatar
  • 31.1k
2 votes
1 answer
167 views

How dark would the sun become if we traversed a Bok globule?

Bart Bok gave his name to dust clouds of 2-50 solar masses, which by their darkness may be 100 times more frequent than telescopes can detect. If the solar system traversed a Bok Globule, how dark ...
bandybabboon's user avatar
  • 4,252
2 votes
1 answer
2k views

What are the so called clouds of dust and gas made of?

We constantly read about "clouds of dust and gas" surrounding a (or being the initial state of a) star, but what elements constitute such dust and gas?
alvaroc's user avatar
  • 123
3 votes
1 answer
659 views

Absolute magnitudes with dust extinction

I have a distant $z\sim3$ galaxy with absolute AB magnitudes $M_B$ and $M_I$, where the central wavelengths of the $B$ and $I$ passbands are $\sim0.4\,\mu\text{m}$ and $\sim0.8\,\mu\text{m}$, ...
ajrlewis's user avatar
2 votes
1 answer
106 views

carbonaceous content of galaxies?

There is a phrase in a Science Daily article which appears to be wrong: The Milky Way has a very high content of carbonaceous dust, which has been shown to be very rare in other galaxies. Is there ...
bandybabboon's user avatar
  • 4,252
2 votes
1 answer
313 views

Is Earth losing orbit? [duplicate]

Is the Earth losing or gaining distance from the sun overall? Could asteroids over time add weight to the Earth and push it farther from the sun more than having a degrading orbit around the sun? Does ...
Muze's user avatar
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