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A collection of ionized gases and dust in interstellar space

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1answer
46 views

What factors makes a star big in size(Physically)?Is the size of the nebula a relevant factor?

(Our sun compared to some of the known stars) I know that the star is born in a nebula.Do only a extremely gigantic nebula give rise to large-radius star or is there any other factors related?
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2answers
241 views

Is this an actual nebula or CGI?

I'm thinking of putting a large wall paper with an astronomical motive on a wall. I found quite a number of wall papers by various vendors, but most of them are obviously computer generated images, ...
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1answer
66 views

Determining line ratios in planetary nebula

I know that the line strength ratio tells us how hot the electron plasma in a nebula is, and also give information about the electron densities in the nebula. But how do you compute the line ratios? ...
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0answers
34 views

Doubt about star formation [duplicate]

When a star runs out of hydrogen, it either goes through supernova or forms white dwarf and planetary nebula. So there should not be much hydrogen left to form a new star in the nebula. So how new ...
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1answer
119 views

Is this a real photo or an art work?

I've never seen this Hubble picture, is it an artist impression? It's fascinating because there are voids apparently cause by supernovae. From the video 1 Hour of Epic Space Music: COSMOS - Volume 1 ...
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1answer
147 views

How to visually tell the difference between a planetary nebula and a supernova remnant?

If we see a nebula by looking through a powerful telescope, how can we tell whether we are looking at the remnant of a supernova or at a planetary nebula? Thanks
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1answer
82 views

Do novas create a nebula? Could a planet survive if its star exploded in a nova?

Does a nova, caused by runaway fusion in hydrogen accreted onto a white dwarf from a companion star, create a visible nebula? If a planet were in a circumbinary orbit around a binary pair that ...
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1answer
191 views

How big is nebula dust?

Whenever I see the term dust for the particles of a nebula, I ask myself whether this is actually based on some reliable measure of particle size. Of course we can all agree it looks like dust from ...
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2answers
110 views

Is this gas cloud or lens effect?

I was going through the zoomable image of Milky way and after zooming to this particular location, we can see a reddish area on the left side of a probably large star. Here is a screenshot I took ...
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1answer
73 views

Why isn't our local interstellar space colorised?

Looking at answers to this question, people seem pretty convinced that human naked eye should be able to see the colour of ionised gas/dust cloud when they are inside an emission nebula. And we know ...
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1answer
259 views

What state of matter are nebulae in?

After doing research it said that nebulas are made of gas and dust. Are they actually gases and solids, or are they plasma?
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1answer
257 views

Why are O III lines so prominent in the spectra of emission nebulae when the amount of oxygen relative to hydrogen is a million times smaller?

Looking at spectra of emission nebulae like the Lagoon Nebula, the $[\text{O III}]$ lines are prominent in intensity. However, the abundance of oxygen is minuscule compared to hydrogen. How then are ...
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1answer
215 views

Is the galaxy made of a nebula or the solar system?

My book says on the topic 'Formation of stars' that a galaxy starts forming by the accumulation of hydrogen gas in the form of very large clouds called nebulae. Then local lumps of gas are formed. ...
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2answers
286 views

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

Regarding molecular clouds / absorption nebulae / Bok globules / obscuring clouds, (I'm not sure if there's one generic term encompassing all those and any similar obscuring clouds - I just used "...
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1answer
1k views

What are the large round dark “holes” in this NASA Hubble image of the Crab Nebula?

I came across this image of the Crab Nebula taken from NASA Hubble telescope. What are the large round "holes" and how are they formed?
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1answer
205 views

What are the dark spots in this Hubble image of the Crab Nebula?

I recently ran into this NASA Hubble image of the Crab Nebula in this article talking about its core. What I am interested to know though is: what are these round dark spots appearing in the image (...
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1answer
130 views

Did we discover how nebulae hold their shapes?

As you know, nebulae such as the Eagle Nebula, the Cat's Eye Nebula, and the Pillars of Creation, have extraordinary shapes. But have we discovered why that is so? I've tried researching it myself ...
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1answer
134 views

Star formation: When a nebula collapses, is it only the gasses that form the star?

A nebula is made of dust (elements heavier than He and H) and gas (H and He). Stars are made when nebulae's collapse and hydrogen begins to fuse. 99% of nebula material goes into making the star. The ...
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0answers
28 views

How long do hot X-ray sources last?

Some X-ray sources in nebulae are caused by hot materials in the millions of degrees that formed in supernovae. What's the cooling rate of this stuff? How long does it stay this hot? I would expect ...
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2answers
185 views

How do I see more than just points in the sky?

I just bought a new telescope with these specifications: Aperture: 203 mm Focal Length: 1200 mm F/ratio: f/5.9 I usually use a 28 mm eyepiece, giving me about 42.5x magnification, but I also have a ...
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2answers
50 views

What's the proper terminology for nebula clouds?

I'm writing a research paper over outer space (yeah, yeah, broad topic) and I'm wondering what the proper terminology for nebula clouds is. This is an excerpt from my paper showing how I'm going to ...
2
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2answers
163 views

How useful are filters for spotting nebulae?

Recently I've been trying to spot a couple of nebulae, IC59 and IC1318. The skies at the site are modestly dark (4.5 on the Bortle scale), I'm using an 8" scope, and I've slowly scanned around the ...
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5answers
661 views

Fusion of elements inside heavy stars

I am confused with nucleosynthesis inside supernovae. I have read that the heavier elements are made through fusion of lighter element's namely hydrogen and helium. Does the star "store" all the ...
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1answer
134 views

Why does hydrogen ionization happen in HII regions?

Why does hydrogen ionization happen in HII regions? Why is the hydrogen there ionized?
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0answers
36 views

What are the implications if the Sun was formed in a warm nebula?

Molecular oxygen O2 has been found on comet 67P/C-G in a ratio of 3.8% to water, which is much higher than expected. An explanation proposed is that the Solar System formed from a molecular cloud ...
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1answer
30 views

What is meant by “short lived” in the duration of a planetary nebula?

In this wikipedia article, it describes planetary nebula as "short-lived," but I'm not sure in relation to what? This could mean billions of years in some contexts. How long is short-lived? Bonus ...
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1answer
57 views

How do proto-planetary nebulae gain momentum?

currently I am curious about proto-planetary nebulae. At first I was curious about how planets spin but I read in a couple of articles that they got their spin from when they were in a proto-planetary ...
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2answers
231 views

How to tell a nebula from a galaxy?

Not all galaxies are spiral in shape[1][2], some nebulae are huge[3] and nebula are the nursery of stars[4]. How to tell them apart? Note I have already compare the contents for galaxy and a nebula, ...
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1answer
55 views

How can I find out which known stars lie within or close to M8

I'm looking for a way to find stars within a certain region of space, the Lagoona Nebula in this case, based on what we currently know. Are there some databases that allow you to make such queries? ...
5
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1answer
147 views

Why is the Boomerang Nebula colder than the CMB?

An earlier answer on temperature mentioned that the temp of the CMB is 2.4K and the temp of the Boomerang nebula as 1K. How did the nebula cool faster than the CMB?
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1answer
443 views

Relationship between temperature of nebula and size of star

I was wondering, in the process of star formation, does the temperature of the nebula that produces a star play a role in the size of that star? I mean, it's only logical that the size would depend on ...
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2answers
2k views

Which eyepieces I can use it for best viewing experience using my exisiting telescope?

Telescope: Orion 09843 SpaceProbe 3,3 inch aperture(76mm), 700mm focal length, eyepieces - 25mm and 10mm focal lengths Hi, I am very happy and excited to see moon craters, jupiter and saturn. And ...
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2answers
2k views

How can I see a nebula?

I've recently been seeing a bunch of pictures of nebulae and I'm just fascinated by their beauty and complexity. Is there any kind of telescope that would make it possible to view it from here on ...
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3answers
2k views

Why is the Eagle Nebula so “static”?

This, of course, is a newbie question, as I am nothing more than a hobbyist. But I was quite surprised to see the recently-released "before and after" pictures of the so-called "Pillars of Creation" ...
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4answers
406 views

Do heavier elements breakdown during supernova?

Heavier elements like gold, uranium etc. are formed at the end of a star's life. As the star explodes into a supernova, it gives rise to nebula which is the birthplace of new stars. But as the star ...
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2answers
482 views

Will new stars stop forming at some point of time?

New stars keep forming in the universe thanks to all the nebulae. Now, we need Hydrogen to form stars and there would a time when all the hydrogen will get exhausted, and no more star formation will ...
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3answers
221 views

Are nebulae only visible from a distance?

There's plenty of data about the density of nebulae, and obviously they're pretty thin. This is space, after all, and these things are really, really big. But I'm wondering about the practical ...
16
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1answer
8k views

How many stars and galaxies can be seen by the naked eye?

How many of the luminous dots that we see naked are galaxies and not stars from our galaxy? I imagine that the majority of the luminous points that we see naked eye during the night, are actually ...
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1answer
93 views

Why is there billowing dust in nebulae?

Why do some nebulae look like the billowing clouds? Wouldn't that require something like a viscosity in empty space?