North Polar Sequence
North Polar Sequence
See magnitude.North Polar Sequence
a group of 96 stars in the vicinity of the north celestial pole with precisely measured photographic and photovisual stellar magnitudes. In 1922 the International Astronomical Union adopted the north polar sequence as the fundamental standard for astronomical photometry. The north polar sequence became less important as a standard in the late 1950’s as a result of the development of photoelectric photometry and the discovery of a number of shortcomings in the sequence as a standard.