Sidereal Wall Clock (Southern Hemisphere) - So what use is a sidereal clock? It is a clock that is linked to the stars rather than the sun and reports the Right Ascension at your local zenith. It can be used to tell which stars are in the sky at any particular time. Move yourself out from the earth and orient yourself according to the nearby stars. From that vantage point, from noon one day to noon the next the earth rotates a full 360 degrees plus another small amount corresponding to the angle the earth has moved in its orbit around the sun, almost one degree, about 1/365th of a circle. In one year, the earth revolves one complete revolution more than the number of days reckoned from the position of the sun in the sky. The sidereal day, the time it takes for the 'fixed stars' to return to the same position in the sky, is a few minutes shorter than the solar day, about 23 hours and 56 minutes. The ratio of the length of the sidereal day to the solar day is approximately 1/1.00273791. A sidereal clock measures time by a scale that has 24 sidereal hours in a sidereal day, so the sidereal hours, minutes and seconds are all slightly shorter than their conventional equivalents. There are no time zones using sidereal time. Sidereal time is not used to organise peoples affairs so there is no motivation to standardise the time between nearby places and every different longitude has its own local sidereal time. Shipping US$24 or equivalent. Southern Hemisphere Star Map on face. Clock diameter is 12" (300mm)Face is 9" (200mm) Battery powered single AA 1.5V included.
Sidereal Wall Clock (Northern Hemisphere) - So what use is a sidereal clock? It is a clock that is linked to the stars rather than the sun and reports the Right Ascension at your local zenith. It can be used to tell which stars are in the sky at any particular time. Move yourself out from the earth and orient yourself according to the nearby stars. From that vantage point, from noon one day to noon the next the earth rotates a full 360 degrees plus another small amount corresponding to the angle the earth has moved in its orbit around the sun, almost one degree, about 1/365th of a circle. In one year, the earth revolves one complete revolution more than the number of days reckoned from the position of the sun in the sky. The sidereal day, the time it takes for the 'fixed stars' to return to the same position in the sky, is a few minutes shorter than the solar day, about 23 hours and 56 minutes. The ratio of the length of the sidereal day to the solar day is approximately 1/1.00273791. A sidereal clock measures time by a scale that has 24 sidereal hours in a sidereal day, so the sidereal hours, minutes and seconds are all slightly shorter than their conventional equivalents. There are no time zones using sidereal time. Sidereal time is not used to organise peoples affairs so there is no motivation to standardise the time between nearby places and every different longitude has its own local sidereal time. Shipping US$24 or equivalent. Northern Hemisphere Star Map on face. Clock diameter is 12" (300mm)Face is 9" (200mm) Battery powered single AA 1.5V included.
Clock movement mechanism and (87mm hands)so you can make your own Sidereal clock. Battery powered (Battery powered single AA 1.5V included.). You can order different hands from Klockit.com. Select from Group A hands. The ones I will ship with the movement are #68034: Sweep Second Hands: Red; Group A from the Klockit catalogue.
Buy two clocks and save. This package includes a Sidereal (Southern) and matching Solar 24 Hour clock. See individual product descriptions for more details. Shipping US$24 or equivalent for the package.
Sidereal Wall Clock single AA 3V Lithium replacement battery for Sidereal clocks brought before 1 July 2010. After that date they are powered by a single 1.5V AA battery
Buy two clocks and save. This package includes a Sidereal (Northern) and matching Solar 24 Hour clock. See individual product descriptions for more details. Shipping US$24 or equivalent for the package.
A 24 hour wall clock (Solar Time) that matches the Sidereal clock. Hang these together and you can watch the earth rotate around the sun as the two times slowly move apart and return at the end of March each year. Shipping US$24 or equivalent. Clock diameter is 12" (300mm)Face is 9" (200mm)Battery powered single AA 1.5V battery included with purchase