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When stars explode after running out of fuel, why are new stars born from the remnants?

New stars are not formed from the nebulae created when a parent star explodes. In space there is thin interstellar gas and plasma. This gas is buffeted and blown by the solar winds of stars, and the ...
James K's user avatar
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32 votes

Why can space telescopes see through a planetary nebula?

Let's say we have a spherical shell of some material emitting light, much bigger than the star it surrounds. If we look right down the center of the shell, our line of sight takes us through only a ...
HDE 226868's user avatar
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29 votes
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What causes the sharp if irregular boundary line in the "Cosmic Cliffs" JWST Carina image?

The "cliff" marks the boundary between the lower, dusty, neutral gas, and the upper ionized region. The ionization is caused by the O and B stars, i.e. the most massive, hottest ones of the ...
pela's user avatar
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29 votes
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Distance of the Crab nebula and the speed of light

You are absolutely right. The convention is that we date astronomical events by when we see them - which is verifiable, useful and absolutely certain. It wouldn’t be useful to know what year BC it ...
Martin Kochanski's user avatar
25 votes
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Is it possible that the Sun and all the nearby stars formed from the same nebula?

There are three main reasons why we can tell that local stars did not, for the most part, form from the same molecular cloud that the Sun formed from. The first is that unless stars are born in a very ...
Peter Erwin's user avatar
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23 votes

When stars explode after running out of fuel, why are new stars born from the remnants?

New stars aren't directly born in the exploded remnants of massive stars. Star formation does not occur in newly produced supernova remnants. Instead what happens is that, over the course of millions ...
ProfRob's user avatar
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23 votes
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Could it be possible to detect planets from stars that went supernova through the resulting nebula shape?

The escape speed of a big planet like Jupiter is about 60 km/s. The speed of the ejecta from a supernova explosion is something like $10^4$ km/s. i.e. Jupiter would have little discernable ...
ProfRob's user avatar
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20 votes
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Why can space telescopes see through a planetary nebula?

Short Answer Thin gas in a nebula only absorbs some portion of star light corresponding to a small subset of the overall visible spectrum, according to the corresponding molecular composition of the ...
Connor Garcia's user avatar
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20 votes

Distance of the Crab nebula and the speed of light

Just to reiterate my comment. The approach is correct but the accuracy is spurious - the number of significant figures is not warranted by the quality of the distance information (the date of ...
ProfRob's user avatar
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19 votes

Is it possible that the Sun and all the nearby stars formed from the same nebula?

Is it possible that the Sun and all the nearby stars formed from the same nebula? No, it is not. Our Sun has marked differences in metals compared to the nearby stars. (In astronomy, every element ...
David Hammen's user avatar
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13 votes
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What are the large round dark "holes" in this NASA Hubble image of the Crab Nebula?

I think my deleted answer to your previous question covers this well, so I'll add it here. These two spots are known as the east and west bays of the Crab Nebula. They appear to be the result of a ...
HDE 226868's user avatar
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13 votes
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Whose name is Minkowski 92 bearing?

Rudolf Minkowski. Its not likely to be the mathematician, Hermann. Nor the physiologist Oskar. There's only one Minkowski who was an observational astronomer. The paper describing M1-92 was https://...
James K's user avatar
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13 votes

How else can a star form, other than gravitational collapse?

About 15ish years ago, this was still a heated and pressing open question: what is the dominant mechanism by which most stars (i.e., low-mass stars) form? This came to the fore in a showdown between ...
Daddy Kropotkin's user avatar
13 votes
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What is the bright orange star?

The best match in SIMBAD appears to be the red supergiant W61 7-8. Though it stands out in this near infrared image, in visible light you would need a 30cm or larger telescope to see it (V=13.6). The ...
Mike G's user avatar
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13 votes
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Are these images of the same nebula?

Yes, sort of. But the Chandra image is of just a small portion at the centre of the Spitzer image. Astronomical objects often have different appearances at different wavelengths. In the case of the ...
ProfRob's user avatar
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11 votes
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Are Brown and Sub-Brown Dwarfs secretly more common than stars?

The answer to your first question is (now) fairly simple: No, brown dwarfs are not more common than red dwarfs. A crude approximation is that stars (which are indeed mostly red dwarfs) outnumber brown ...
Peter Erwin's user avatar
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10 votes
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What kind of nebula was the Sun formed from?

Stars and the planetary systems around them form from dark and dense molecular clouds. Physically we distinguish Hot ionized gas (supernova remnants and emission nebulae) Hot neutral gas (also some ...
planetmaker's user avatar
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9 votes
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How big is nebula dust?

The size of cosmic dust grains is in general given not by some size, but by a size distribution. The only direct measurements of such a distribution are made on dust collected on plates of satellites, ...
pela's user avatar
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9 votes

Is Barnard 68 the only cloud so close to us that there are no stars between us and it?

Barnard 68 has a surface area of around 10 square arcminutes on the sky and is at an estimated distance of around 160 pc. The volume of space encompassed by a sightline to Barnard 68 is therefore ...
ProfRob's user avatar
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9 votes
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Why do stars rotate slower than they're expected to?

There are two phases to this problem. In order to accrete into stars, a huge amount of angular momentum must be lost to allow so much mass to gather into a small volume. A second problem is how stars ...
ProfRob's user avatar
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9 votes
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The physical processes of emission lines in cosmic nebula

Just a short answer, and likely others will fill in more details. If there is ionization of some atoms, then generally there is recombination as well - you will have both processes going on, roughly ...
Eric Jensen's user avatar
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9 votes

What kind of nebula was the Sun formed from?

Stars are formed in molecular clouds: these are gas clouds with conditions for $H_2$ to form. Molecular clouds are typically dark nebulae, but if there is a bright star near them, then they can ...
James K's user avatar
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9 votes

Distance of the Crab nebula and the speed of light

The distance to the crab nebula is uncertain. It is probably between 4900 and 8100 light years away, (with a best guess of 6500 light years). It is sometimes surprising that astronomers can measure ...
James K's user avatar
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9 votes
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Why does Helix Nebula look like an eye?

Look at Helix Nebula NGC 7293 (Aquarius) on the left and Ring Nebula M57 (Lyra) on the right. Both are of the planetary nebula type, and very similar. This NASA video, based on Hubble Space Telescope ...
Albert's user avatar
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8 votes
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Whose name is Fleming 1 nebula bearing?

Annes Astronomy News says: Fleming 1 is a planetary nebula that lies about 10,000 light-years away in the constellation of Centaurus, while moving away from us at approximately 28.6 kilometers per ...
uhoh's user avatar
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8 votes

Why can space telescopes see through a planetary nebula?

The answer is quite simple: you can also see the other side of the room (or maybe through the fume or haze above your oven) when you create a tasty meal) - even when the space between you and the wall ...
planetmaker's user avatar
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8 votes

How else can a star form, other than gravitational collapse?

"Almost all" is likely just a writing mistake. However, I know of at least one other way to get stars that is not due to gravitational collapse and has been discussed in serious papers. In (...
Anders Sandberg's user avatar
7 votes
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Is Barnard 68 the only cloud so close to us that there are no stars between us and it?

First query: YES there are many bok clusters without foreground stars. For density, That's an unclear field of study, confused with dark matter enigma, and the estimates of frequency of "Boks" ...
bandybabboon's user avatar
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7 votes
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How useful are filters for spotting nebulae?

With an 8" scope, a filter will very likely give you better results than observing without a filter. Although a filter does block light, the crucial aspect is that a filter increases contrast (by ...
user13087's user avatar
7 votes

Will the nebula of Betelgeuse be visible to the naked eye? How bright, how large, how soon, for how long?

There is an article here that describes the visible effects quite well. In essence, within a week or so, it would be comparable in brightness to the moon and therefore visible during the day. ...
sforsingh's user avatar
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