Do all stars belong to galaxies?

In summary: Essentially it shows that there are hundreds of billions of galaxies in the observable universe, each containing hundreds of billions of stars. The distances between these galaxies are unimaginably vast, but it also shows that even in this vastness, there are still clusters and filaments of galaxies held together by gravity, making the universe seem a little less empty.In summary, the conversation discusses the relationship between stars and galaxies, with the conclusion that most visible stars are part of our galaxy. The space between galaxies is incredibly vast, with distances measured in light years. It is also mentioned that there can be rogue stars and planets that have been gravitationally pulled from their galaxies. The vastness of the universe is further emphasized, with the mention of hundreds of billions of
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Hot Star
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This is probably quite a basic question but my mind has been ignited by the recent stargazing programs on the bbc so...

Does every star have to be associated with a galaxy? For example, when looking through a telescope you see either individual stars or spiral galaxies - when looking at these with the naked eye then they're virtually indistinguishable - so does that mean that every lone star visible is part of our galaxy?

So if that's the case then the space between galaxies is just literally astronomically almost unfathomable.

The space between stars in the milky way is vast but I'm struggling to get my head around the distance between galaxies.

If what I question above is true then there are huge lengths of space out there with nothing whatsoever in for millions and millions of miles.
 
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  • #2
Hot Star said:
This is probably quite a basic question but my mind has been ignited by the recent stargazing programs on the bbc so...

Does every star have to be associated with a galaxy? For example, when looking through a telescope you see either individual stars or spiral galaxies - when looking at these with the naked eye then they're virtually indistinguishable - so does that mean that every lone star visible is part of our galaxy?
The individual stars that we see are in our galaxy. That is not to say that there cannot be stars outside of our galaxy (we have in fact seen stars that are traveling too fast to remain in our galaxy), but they would be too faint to see for the most part. We do know that there can't be too many, or they would tend to increase the background radiation of the night sky.
So if that's the case then the space between galaxies is just literally astronomically almost unfathomable.

The space between stars in the milky way is vast but I'm struggling to get my head around the distance between galaxies.

If what I question above is true then there are huge lengths of space out there with nothing whatsoever in for millions and millions of miles.

Millions and millions of miles is would better describe the distances between planets of the Solar system. Galaxies are separated by millions of light years, with a light year being ~6 trillion miles.
 
  • #3
It looks like a mind-bender, but you have to look at the big picture. A really really big picture. If you can accept that 99.8% of the stars we can see with our naked eye are in our own galaxy, and that the stars in other galaxies appear as a couple of bright ones because they are that far away, you can start to make sense of it. Visualize yourself leaving the Earth and flying past the stars and into deep space between the galaxies - The further away from the milky way you go (which is huge to start with) the stars become closer and closer together and the milky way gets smaller until you are flying into Andromeda, the closest galaxy to us, but in this fantasy you're flying at a few hundred times the speed of light, so spread the time out a little. That is how I make sense of things. And by the way, I enjoyed the stargazing live episodes too.
 
  • #4
Hot Star said:
This is probably quite a basic question but my mind has been ignited by the recent stargazing programs on the bbc so...

Does every star have to be associated with a galaxy? For example, when looking through a telescope you see either individual stars or spiral galaxies - when looking at these with the naked eye then they're virtually indistinguishable - so does that mean that every lone star visible is part of our galaxy?

So if that's the case then the space between galaxies is just literally astronomically almost unfathomable.

The space between stars in the milky way is vast but I'm struggling to get my head around the distance between galaxies.

If what I question above is true then there are huge lengths of space out there with nothing whatsoever in for millions and millions of miles.


The spaces between individual stars, between individual galaxies, between individual clusters of galaxies and between superclusters of galaxies is mostly empty space. However, now and then we might come across a rogue planet, brown dwarf, or star which has been gravitationally wrenched from its galactic location by galactic collisions, near misses, or by the slingshot effect caused by orbiting too near a galactic black hole. Stars destined for such a fate can be recognized by their galactic escape velocity which will ultimately destine them to that fate.

.
 
  • #5
Thanks for all the posts which have been very helpful and just so mind boggling that I now wish to dig a hole and hide away from the unfathomable nature of the distances we are talking about...

"6 trillion miles" = a light year and there are millions of light years between galaxies - there's a lot of space out threre :(.
 
  • #6
"An object will stay remain at rest or continue at its constant velocity unless acted on by an external unbalanced net force", Newton's second law.
_________________
kinds of cats|types of cats
 
  • #7
Hot Star said:
Thanks for all the posts which have been very helpful and just so mind boggling that I now wish to dig a hole and hide away from the unfathomable nature of the distances we are talking about...

"6 trillion miles" = a light year and there are millions of light years between galaxies - there's a lot of space out threre :(.

Look up the Hubble Ultra Deep Field on wikipedia and youtube...it will blow your mind.
 

1. What is a star?

A star is a massive, luminous sphere of plasma held together by its own gravity. It generates and emits energy through nuclear fusion reactions in its core, producing heat and light.

2. How are stars classified?

Stars are classified based on their size, temperature, and brightness. The most commonly used classification system is the Morgan-Keenan (MK) system, which categorizes stars into seven main types: O, B, A, F, G, K, and M. These types are further divided into subcategories based on their temperature and luminosity.

3. What is a galaxy?

A galaxy is a massive collection of stars, gas, dust, and dark matter bound together by gravity. They come in various shapes and sizes, and there are estimated to be billions of galaxies in the observable universe.

4. How are galaxies formed?

Galaxies are formed through the process of accretion, which is the gradual buildup of matter through gravitational attraction. The most widely accepted theory is that galaxies formed from small fluctuations in the early universe, which eventually grew and merged to form larger structures.

5. How are stars and galaxies related?

Stars are the building blocks of galaxies, as they make up the majority of the visible matter in a galaxy. They play a crucial role in the formation and evolution of galaxies through their gravitational interactions and the energy they release. Without stars, galaxies would not exist.

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