Mesmerism

DefinitionMesmerism is a historical theory and practice developed by Franz Anton Mesmer in the eighteenth century. Mesmer proposed that an invisible force...

Meridional

DefinitionMeridional means southern or relating to the meridian, the north–south great circle that passes through the zenith and the celestial poles. The...

Meridian Distance

DefinitionMeridian Distance is the angular distance between a celestial body’s hour circle and the local celestial meridian. It is measured along the...

Meridian

DefinitionThe meridian is the celestial great circle that passes through the north and south celestial poles, the observer’s zenith, and the nadir...

Algol, in the constellation Persus

DefinitionAlgol is a prominent eclipsing binary star in the constellation Perseus, traditionally identified with the severed head of Medusa. Also known as...