Your quote is incomplete, the next two sentences are an important part of it:
" How far away is it?
Over nine billion light-years away."
To see the light of a star that far away is indeed "incredible" as in "so extraordinary as to seem impossible".
The following paragraphs then explain why it appears to be legit (" Then I read the paper, played with the math a little, and, sure enough, this appears legit.").
" How far away is it?
Over nine billion light-years away."
To see the light of a star that far away is indeed "incredible" as in "so extraordinary as to seem impossible".
The following paragraphs then explain why it appears to be legit (" Then I read the paper, played with the math a little, and, sure enough, this appears legit.").