How is it possible to see stars that are billions of light years away?
As light travels a certain distance, it typically loses intensity. This is due to light scattering, which occurs when the light sometimes comes into contact with dust, gas clouds, or other fine particles. (Space)
While there is a vacuum in space, it's important to note that it's not a perfect vacuum. This is because the vacuum is only nearly perfect, because, as already mentioned, space contains small amounts of dust, gas clouds, and fine particles.
Now, if the light hits dust, gas clouds, and fine particles in space at certain points on its way to Earth and is thus absorbed or diverted, I wonder how the light, which is millions to billions of light years away, can reach Earth and be recorded.
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Uh, photons lose energy only when they emit these to atoms by resonance absorption or when they are reflected. This follows, in a large vacuum with little mass in between and a large photon source some photons can travel a large distance.
Individual stars in billions of light years distance can also not be recognized with the largest telescopes, because the resolution is lacking and also because the light of a star at the distance would be far too weak. In billions of light years distance, however, large accumulations of stars can still be seen, i.e. galaxies, even if these are often only point-shaped light sources. Light not only weakens, but also the wavelength increases with increasing distance of the light source, because the light source is always removed from us, the farther away, the faster the source is removed by expansive force of the universe, with all objects outside the local group. galaxies of the very young universe can therefore often only be detected in the infrared range, with special infrared telescopes.
Icarus
Red shift z=1.49 = 9 billion light years
https://www.nationalgeographic.de/wissenschaft/2018/04/gravitationlens effect-removedester-stern-wird-sichtbar
This is incredible, so in this individual case it has been possible to observe a star from billions of light years distance.
Many thanks for finding this important and enriching information.
Just looked at whether something has been happening since the discovery of Icarus, with regard to finding, and stars through gravity lenses.
It’s like:
Yes, I was not aware of the fact that this is possible at all, even though the principle of an engraving lens was known to me. But billions of light years in a single star? I would never have believed without serious sources.
Individual stars do not look at this distance. You can see whole galaxies or their active cores. And between the super piles there is enough real vacuum with great free path lengths for radiation. The universe is not a ravaged pub.
.. but at the end of the universe there shall be one …
MACS J1149 Lensed Star 1
MACS J1149 Lensed Star 1, from his discoveries around Patrick Kelly Icarus is a blue overflow. The star has a red shift of z=1.49, which is about a distance from 9 billion light years in accordance with the provisions of this Regulation. The overflow is only visible thanks to an extreme gravity lens effect of the galaxy cluster MACS J1149 in combination with another compact object with about three solar masses. These objects, which are located in front of the star, amplify their light approximately 2000 times.
With enough energy everything goes
There are also more galaxies consisting of hundreds of billions of stars than single stars. And they are so light awake that you have to be exposed for 10 days.
Check out the pictures of the Pluto mission “New Horizons” in July 2015.
There you can see the Earth on a photo as a single pixel – from a distance of 4,772 billion kilometers. The sun itself is only 150 million. km further away and still a huge bright star.
And since our sun is not exactly the largest, other suns with their huge size create a lot of other paths with their light.
What you should not forget: Most of the suns we see are in our own galaxy. Many other distant “stars” are themselves galaxies from infinitely many suns.
Now, with “normal” stars, this is not possible at the moment, as the resolution of current telescopes is far from sufficient. However, it is possible that the JWT has just discovered exotic dark-matter stars:
https://www.scinexx.de/news/kosmos/have-astronomen-dunkle-sterne-discovered/
Well, with the naked eye you don’t see if a star is billions of light years away.
As these stars shine more brightly than the sun million times.