There are 4.8 million stars in the sky, each of which can identify Zhuge Liang's intention to revive the Han Dynasty. "Star" refers to the stars in the sky, and "4.8 million" is an imaginary number. This is a line created by Youka, the number is not exact, and it mainly represents a lot. "Zhao Jian" means identification and clarity, which means that these stars can understand Zhuge Liang's determination to revive the Han Dynasty.
Baidu's answers are Du Fu's Frontier fortress, Zhao Kuangyin's Stars and Bing Xin's, so I can't comment on these answers, because I haven't found anything about this sentence in these three sources. Please correct me if my answer is wrong.