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  2. Sidereal time - Wikipedia

    en.wikipedia.org/wiki/Sidereal_time

    Although ERA is intended to replace sidereal time, there is a need to maintain definitions for sidereal time during the transition, and when working with older data and documents. Similarly to mean solar time, every location on Earth has its own local sidereal time (LST), depending on the longitude of the point.

  3. Sidereal year - Wikipedia

    en.wikipedia.org/wiki/Sidereal_year

    The sidereal year differs from the solar year, "the period of time required for the ecliptic longitude of the Sun to increase 360 degrees", [2] due to the precession of the equinoxes. The sidereal year is 20 min 24.5 s longer than the mean tropical year at J2000.0 (365.242 190 402 ephemeris days). [1]

  4. History of timekeeping devices - Wikipedia

    en.wikipedia.org/wiki/History_of_timekeeping_devices

    The weight-driven mechanical clock controlled by the action of a verge and foliot was a synthesis of earlier ideas from European and Islamic science. Mechanical clocks were a major breakthrough, one notably designed and built by Henry de Vick in c. 1360 , which established basic clock design for the next 300 years.

  5. Synodic day - Wikipedia

    en.wikipedia.org/wiki/Synodic_day

    The synodic day is distinguished from the sidereal day, which is one complete rotation in relation to distant stars [1] and is the basis of sidereal time. In the case of a tidally locked planet, the same side always faces its parent star, and its synodic day is infinite. Its sidereal day, however, is equal to its orbital period.

  6. Hour angle - Wikipedia

    en.wikipedia.org/wiki/Hour_angle

    The local hour angle (LHA) of an object in the observer's sky is = or = + where LHA object is the local hour angle of the object, LST is the local sidereal time, is the object's right ascension, GST is Greenwich sidereal time and is the observer's longitude (positive east from the prime meridian). [3]

  7. Science fair - Wikipedia

    en.wikipedia.org/wiki/Science_fair

    A science fair or engineering fair is an event hosted by a school that offers students the opportunity to experience the practices of science and engineering for themselves. In the United States, the Next Generation Science Standards makes experiencing the practices of science and engineering one of the three pillars of science education.

  8. Sidereal - Wikipedia

    en.wikipedia.org/wiki/Sidereal

    Sidereal, meaning "of the stars", may refer to: Sidereal time; Sidereal day; Sidereal month; Sidereal year; Sidereal period of an object orbiting another astronomical object; Sidereal and tropical astrology

  9. Astronomical clock - Wikipedia

    en.wikipedia.org/wiki/Astronomical_clock

    A domestic clock housed in a wooden case, it gives indications including the solar, mean and sidereal time around the world, the positions of the constellations and planets, and the appearance of Halley's Comet. [17] Sint-Truiden. The astronomical clock constructed by Kamiel Festraets between 1937 and 1942 is now housed in the Festraets Museum.