Apsidal

Apsidal refers to anything related to or resembling an apse, which is a semicircular or polygonal termination or recess in a building, typically found at the eastern end of a church. The term is often used in architecture and astronomy.

Architecture

In architecture, an apsidal structure is one that includes an apse. The apse is a prominent feature in many Christian churches, where it often houses the altar. The design of the apse can vary, but it is usually semicircular in shape and may be covered with a dome or a vaulted ceiling. The apse is often richly decorated with mosaics, frescoes, or other forms of art.

Examples of Apsidal Structures

• Basilica of San Vitale
• Hagia Sophia
• St. Peter's Basilica

Astronomy

In astronomy, the term apsidal refers to the points of the orbit of a celestial body where it is closest to or farthest from the body it is orbiting. These points are known as the apsides. The closest point is called the periapsis, and the farthest point is called the apoapsis. The line connecting these two points is known as the line of apsides.

Types of Apsides

• Perihelion and Aphelion (for objects orbiting the Sun)
• Perigee and Apogee (for objects orbiting the Earth)
• Periastron and Apastron (for objects in a binary star system)

Related Pages

• Apse
• Church architecture
• Orbit
• Periapsis
• Apoapsis
• Line of apsides