Description: The celestial equator is defined as the great circle of the celestial sphere, whose plane is perpendicular to the axis of rotation of the Earth. In essence, it is the projection of the Earth's equator onto the celestial sphere.

Related Terms:

• Celestial Coordinates
• Celestial Sphere

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".