Residency is a stage of graduate medical training. A resident or house officer is a physician (holding either a M.D. , D.O. , MBBS, MBChB, BMed or D.P.M. degree) who practices medicine usually in a hospital or clinic.The definition of residency varies worldwide by country and structure of the medical industry.esidency is a stage of graduate medical training. A resident or house officer is a physician (holding either a M.D. , D.O. , MBBS, MBChB, BMed or D.P.M. degree) who practices medicine usually in a hospital or clinic.
In astronomy, the term period usually refers to how long an object takes to complete one cycle of revolution. In particular the orbital period of a star or planet is the time it takes to return to the same place in the orbit. Quasi-periodic oscillation. Jump to: navigation, search.
Astronomical Twilight. The last phase of twilight is known as astronomical twilight, or âastroâ for short. This period of twilight occurs when the center of the sun is between 12 and 18 degrees below the horizon and slowly degrades over a period of 30 minutes before night time officially begins.