Questions tagged [nebula]

A collection of ionized gases and dust in interstellar space

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20
votes
2answers
1k 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 ...
29
votes
2answers
25k 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 ...
4
votes
1answer
206 views

Whose name is Fleming 1 nebula bearing?

Fleming 1 is an unusual planetary nebula situated in the Centaurus constellation. Yet it is not clear after who it was named
8
votes
1answer
293 views

Why is the Boomerang Nebula colder than the CMB?

An earlier answer on temperature mentioned that the temp of the Cosmic Microwave Background (CMB) is $2.4\,{\rm K}$ and the temp of the Boomerang nebula as ${\rm 1\,K}$. How did the nebula cool faster ...
3
votes
1answer
165 views

Nebula and its colors

A Nebula has bright awesome colors that include red, blue, green, orange, white, etc? They're result of excitation of electrons. Is there a clear explanation as to which color is attributed to an ...
3
votes
2answers
233 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 ...
3
votes
4answers
2k 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 ...
14
votes
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?
4
votes
1answer
137 views

Why was StDr56 discovered only now?

StDr56 is a newly discovered planetary nebula (maybe). link1 link2 It was found by amateur astronomers Marcel Drechsler and Xavier Strottner. According to the above articles, it's pretty big: With an ...
16
votes
2answers
2k views

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

I was looking at a map of our local stellar neighborhood, and it occured to me, the stars are really close, if one compares them to the size of some nebulae. So can it be, that the Sun, Alpha Centauri ...
9
votes
1answer
352 views

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

When Betelgeuse goes core collapse supernova it will leave a supernova remnant. Will it become visible to the naked eye? If so, in what time frame will it be visible. Will it be star like from the ...
8
votes
3answers
764 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 ...
6
votes
1answer
2k 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 ...
4
votes
1answer
103 views

How can an accretion disk form around the central star of a planetary nebula?

I was reading the 2012 paper A tidally destructed massive planet as the progenitor of the two light planets around the sdB star KIC 05807616 about the possible origin of two exoplanets that orbit a ...
3
votes
1answer
253 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 (...