What is the term for the region around a star where liquid water can exist on the surface of a planet?

The term commonly used to describe the region around a star where conditions are just right for liquid water to exist on the surface of a planet is "habitable zone." This zone is sometimes referred to as the Goldilocks zone, but the more formal terminology within scientific contexts is the habitable zone.

In this region, temperatures allow for the presence of liquid water, which is critical for life as we understand it. If a planet is too close to its star, it may be too hot, causing any water to evaporate. Conversely, if it is too far away, temperatures could cause water to freeze. Therefore, the habitable zone is essential for planets to potentially support life.

While some may confuse the terms, the most accurate term regarding potential habitability is "habitable zone." The Goldilocks zone specifically illustrates the concept of optimal conditions for liquid water and is synonymous with the habitable zone but is less formal. Other terms like "red zone" and "safe zone" do not accurately reflect the established astronomical concept related to liquid water's existence on celestial bodies.