sidereal hour angle
71List of electronics topics — Alphabetization has been neglected in some parts of this article (the b section in particular). You can help by editing it. This is a list of communications, computers, electronic circuits, fiberoptics, microelectronics, medical electronics,… …
72Earth's rotation — is the rotation of the solid Earth around its own axis. The Earth rotates towards the east, which can be observed by orientation with a magnetic compass at sunrise. As viewed from the star Polaris, the Earth turns counter clockwise. Rotation… …
73Global Positioning System — GPS redirects here. For other uses, see GPS (disambiguation). Geodesy Fundamentals …
74Mercury (planet) — Mercury  ☿ …
75Universal Time — (UT) is a timescale based on the rotation of the Earth. It is a modern continuation of Greenwich Mean Time (GMT), i.e., the mean solar time on the meridian of Greenwich, and GMT is sometimes used loosely as a synonym for UTC. In fact the… …
76second — 1. (s or sec or ) a fundamental unit of time in all measuring systems and the SI base unit of time. The name simply means that this unit is the second division of the hour, the minute being the first (see minute [0]). The second was defined …
77List of astronomy acronyms — This is a compilation of acronyms commonly used in astronomy. Most of the acronyms are drawn from professional astronomy and are used quite frequently in scientific publications. However, a few of these acronyms are frequently used by the general …
78Binary star — For the hip hop group, see Binary Star (band). Hubble image of the …
79Analemma — was also a book by Ptolemy .In astronomy, an analemma (IPA: IPA|/ˌænəˈlɛmə/, Latin for the pedestal of a sundial) is a curve representing the angular offset of a celestial body (usually the Sun) from its mean position on the celestial sphere as… …
80Classical planet — For the failed IAU planet category of Classical planets, see 2006 definition of planet. ‹ The template below (Astrology) is being considered for merging. See templates for discussion to help reach a consensus. › Astrology …
