What is formed when a comet is heated and gas particles are pushed away by sunlight?

When a comet approaches the Sun, the heat causes its icy nucleus to vaporize and release gas and dust particles. This process creates two distinct tails that can be observed. The luminous tail, also known as the ion tail, is directly affected by solar radiation. When the gas particles are heated and ionized, they are pushed away from the comet by the pressure of sunlight and solar winds. This results in a tail that consists largely of ionized gases that glow, which is why it is referred to as the luminous tail.

While the dust tail is also created by the comet and is made up of larger particles that are not as affected by solar wind, it does not exhibit the same ionization and glow that the luminous tail does. The ionospheric cloud and solar wind options do not pertain to the phenomena occurring specifically with the comet’s tails arising from solar heating and gas expansion. Therefore, the luminous tail is the correct answer as it directly correlates to the process of gas ionization and expansion due to the Sun's heat and radiation.