Question

why life is not possible on stars​

Answer 1

Alas, life is pretty much guaranteed a quick trip to vaporization if it tried to live in the atmosphere of a star like our own. Stars like our sun have a surface temperature of about 10,000 degrees Fahrenheit (or about 5800 Kelvin), which is hot enough to keep iron suspended in a plasma, and to melt even the hardiest known compounds and alloys.

This is way, way too hot for any kind of biological structure; any kind of complex molecule would immediately burn.

That's not to say that there’s no hope for atmospheric living, so long as we're willing to look at a slightly cooler place.