Not exactly. While the sun's heat does play a role, the tail of a comet is primarily created by the pressure of sunlight and the solar wind.

Here's a breakdown:

* Sunlight: As a comet approaches the sun, its icy core begins to vaporize. This process creates a cloud of gas and dust, known as the coma. Sunlight then pushes this material away from the comet, forming a tail.

* Solar Wind: The solar wind, a stream of charged particles flowing from the sun, also interacts with the comet's coma, further pushing the dust and gas away.

So, the sun's heat doesn't directly create the tail, but it's the driving force behind the process that leads to its formation.