Which of these stars has the coolest surface temperature? a. a starb. f starc. g stard. k star

D. K star

Explanation:

Stars are classified into different groups according to their peak wavelength and their surface temperature.

In particular, we have the following group of stars, which correspond to the following surface temperatures:

Group O - Temperature > 25,000 K

Group B - Temperature 11,000 - 25,000 K

Group A - Temperature 7,500 - 11,000 K

Group F - Temperature 6,000 - 7,500 K

Group G - Temperature 5,000 - 6,000 K

Group K - Temperature 3,500 - 5,000 K

Group M - Temperature < 3,500 K

So among the options given, the star with the coolest surface temperature is star in group K.

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

answer: its c lololo