Found this on social media. Looks correct.
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OK, so let’s explore the visibility of the sun and stars:
Setup:
The lowest level intensity that the human eye can see, is about 10^(−10) [W/m2] https://biology.stackexchange.com/questions/111095/what-is-the-minimum-light-intensity-that-a-human-eye-can-detect.
Actually, the lowest threshold seem to be higher, but let’s assume a superhuman eye.
The most intense supernovas are estimated to shine up to 100.000 times stronger (more …