An astronomer's view of the pole.
Abstract
The paper first discusses in somewhat general terms the coordinate system used for measuring the positions and motions of celestial objects. It then reviews in more detail the theory of positional observations and the motion of the earth about its centroid, followed by an examination of the exact definition of the celestial pole. Once it is accepted that local short-term changes in observatory coordinates have to be applied in any case, it seems that the best solution would be to adopt as the definition of the ephemeris pole the pole of figure of rigid model earth with zero Eulerian motion, and that the model should be dynamically symmetrical about the axis of figure. A quite self-consistent framework for fundamental astrometry is obtained by adopting the axis of figure as the definition of the celestial pole and measuring ephemeris sidereal time around the corresponding equator instead of the equator corresponding to the rotation axis as is at present.
- Publication:
-
Contemporary Physics
- Pub Date:
- April 1979
- DOI:
- 10.1080/00107517908219100
- Bibcode:
- 1979ConPh..20..211M
- Keywords:
-
- Astrometry;
- Astronomy;
- Celestial Geodesy;
- Earth (Planet);
- Polar Regions;
- Astronomical Coordinates;
- Earth Rotation;
- Ephemerides;
- Geodetic Coordinates;
- Nutation;
- Polar Wandering (Geology);
- Precession;
- Astronomy;
- Positional Astronomy;
- Astrometry