~, however, suggests that 79 Ceti b may a very dim redĭwarf star, like Gliese 623 A (M2.5 V) and B (M5.8Ve) at lower right. ~: The precise measurement of objects' positions in the sky.Īstronomical Unit: Abbreviated 'A.U.' It is the average distance between the sun and Earth, approximately 149.6 million km (93 million miles).īranch of astronomy that focuses on measurements, especially those relating to positions and movements. See Units of Distance for a nice diagram. ★ Astronomical Unit (au or ua) The average distance between Earth and the Sun - roughly 149.6 million km. ★ ~ The study of the precise measurement of positions and motions of celestial bodies. When we determine the equatorial coordinates of a few known stars, we can calibrate the image so that when our cursor is located anywhere on the image, we will know the equatorial coordinates of the cursor location. ~ determines where an object is in an image. ~ is the precise measurement of the position and motion of astronomical objects, often with respect to standard star catalogues. Measuring an object's position in the sky. A unit of distance, equal to 149 600 000 kilometres (92 900 000 miles). The mean distance between Earth and the Sun. The branch of astronomy that deals with precisely measuring the positions of objects on the celestial sphere.Īstronomical Unit (AU). ~ is the branch of astronomy dealing with the measurement of the positions and motions of heavenly bodies.Īstronomical unit (AU) a unit of length which is equal to the mean distance of the earth from the Sun. Advances in technology may soon permit a 1,000-fold improvement in the measurement of positions, and thus in our ability to determine distances to stars and galaxies.

The branch of astronomy concerned with measuring the positions of celestial objects. ~ - The precise measurement of the position and motion of astronomical objects.Īten asteroid - Asteroids that are closer to the Sun than the Earth is. For comet orbit computations, ~ good to 1' or 2' (1 or 2 arc seconds), or better, is the standard nowadays. The careful, precise measurement of astronomical objects, usually made with respect to standard catalogues of star positions.

Astrometry online