The bright glowing gases at the central part of a comet are called the coma.

Here's a breakdown:

* Comet's Nucleus: This is the solid, icy heart of the comet. It's composed of frozen gases (like water, carbon dioxide, and methane) mixed with dust and rock.

* Coma: As a comet approaches the sun, the heat causes the ice in the nucleus to sublimate (turn directly from a solid to a gas). These gases, along with dust particles, form a large, luminous cloud surrounding the nucleus, which we call the coma.

* Tail: The solar wind pushes the gas and dust away from the comet, forming the tail. There are two main types of tails: a dust tail (which curves slightly) and a gas tail (which points directly away from the sun).

So, the coma is essentially the atmosphere of a comet, created by the sublimation of the nucleus's ice.