Astar in the sky is best modeled by a

A star in the sky is best modeled by a pentagram.

Explanation:

When the stars in the sky are to be projected on a considerably smaller scale, the shape used to represent the stars is that of a 'pentagram'. A pentagram is defined as a five-pointed star with all five lines of the same length and all internal vertices of the same angle. A pentagram is also called as a 'star polygon' or a 'pentalpha'.

Answertropical depression;

Answer volcanic eruptionsseismic waves from earthquakes;