# Tag Info

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### Why is the Eagle Nebula so "static"?

It appears to be static because it's huge beyond your imagination. The distance to the nebula is 7,000 light years. Its apparent size is 7 arc minutes. Therefore its linear size is about 14 light ...
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### 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 ...
• 34.1k
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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 ...
• 91.2k
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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 ...
• 33.8k
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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 ...
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### Why is the Eagle Nebula so "static"?

To add to Florin Andrei's answer, with an image height of 7,000 pixels for 14 light years, that's 17.5 light hours per pixel. That's 20 billion kilometres per pixel. To make a change in a single pixel ...
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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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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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://...
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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 ...
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### How can I see a nebula?

Yes, indeed! Many nebulae are visible from Earth in a small and cheap telescope, and even to the naked eye (if you are standing in a sufficiently dark place). In fact, yesterday I was watching the ...
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### Why is the Eagle Nebula so "static"?

If you go to this site, http://heritage.stsci.edu/2015/01/supplemental.html , there is a set of comparison photos. The movement that is detectable is very slight but it is there.
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### Why is the Boomerang Nebula colder than the CMB?

The Boomerang Nebula (or Bow Tie Nebula) is a cloud of gas being expelled from a dying low-mass star, at $164~\mathrm{km}~\mathrm{s}^{-1}$ (cf. Raghvendra Sahai and Lars-Åke Nyman: The Boomerang ...
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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 ...
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### 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 ...
• 118k
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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, ...
• 33.8k
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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 ...
• 118k
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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 ...
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### Why does hydrogen ionization happen in HII regions?

Stars are responsible. HII regions$^\dagger$ can refer to several things, but usually I guess one thinks of the volumes around star-forming regions. The more massive a star is, the faster it burns ...
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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 ...
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### 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 ...
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### 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 (...
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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 ...

### 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. ...
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### Is there a Vela Nebula?

The Vela Pulsar (PSR J0835-4510 or PSR B0833-45) is a radio, optical, X-ray- and gamma-emitting pulsar associated with the Vela Supernova Remnant in the constellation of Vela. First line of the ...
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### Are Brown and Sub-Brown Dwarfs secretly more common than stars?

This is an important question to ask about the initial mass function of objects in the Galaxy - and the final answer hasn't been cast as it is a matter of research. Yet, observational data (e.g. see ...
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The peak absolute magnitude of a Type Ia supernova is -19.5. The relation between absolute and apparent magnitude for nearby objects ($z \approx 0)$ is $$m = M + 5\,(\log_{10}(d) - 1)$$ where $d$ is ...