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By now you’ve no doubt read about the #jameswebbspacetelescope observing #galaxies that are the most distant and earliest ever seen, but how can astronomers be sure these aren’t more recent and closer? #Space #astronomy #scicomm https://www.space.com/how-do-we-tell-age-of-galaxies
@RobertLea
The distance to a galaxy can be found if that galaxy has a Type 1A supernova. These stars are formed when a white dwarf has a large companion star that it draws material from. After awhile the white dwarf becomes overloaded and explodes as a Type 1a supernova.
It turns out that all these supernova have the same brightness. So, if one of them seems half as bright as one in another galaxy, that dim one is twice as far away as the other.
Type 1A supernova were used in the supposition that there's Dark Energy out there. To see more on all of this, look at this YouTube https://www.youtube.com/watch?v=0b6t0jO7IgQ
#Space #astronomy #astrophysics #Science