Transit circle
| (Astron.) | a transit instrument with a graduated circle attached, used for observing the time of transit and the declination at one observation. See Circle, n., 3. |
See also: Transit
| 单词 | transit circle | ||
| 释义 | Transit circle
See also: Transit transit circletransit circle(meridian circle) An optical telescope mounted in such a way that it can swing only in a vertical north-south plane. It is used to measure the positions of celestial bodies with great accuracy as they cross the meridian of the telescope site (see culmination). The altitude of a body as it crosses the meridian is now usually measured very precisely by electronic devices; earlier instruments used an accurately graded circular scale set in the vertical plane. The declination of the body can then be determined using the latitude of the observatory. Measurement of the precise local sidereal time at the meridian passage determines the right ascension of the body.transit circle[′trans·ət ‚sər·kəl] |
||
| 随便看 |
|
英语词典包含2567994条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。