Systematic Reductions of 19TH Century Planetary Observations
Abstract
Systematic reductions of nineteenth century observations to the system of the FK4 are discussed. Reductions made on a nightly basis are described and compared with the results obtained through the use of conventional tables. The series of observations made at the Paris Observatory from 1837 to 1881 was used to compare the two methods, and a combined system of 24 000 FK4, FK4 Sup and AGK 3R positions and proper motions provided the reference stars. The results show that for Uranus the mean error of a single observation in right ascension is ±1.″.33 when tables are used for the reductions, and ±1.″12 when nightly reductions are made, while in declination the corresponding mean errors are ±0.″88 and ±0.″80. The observations of Neptune show an even greater difference between the two methods; the mean errors for the tabular and nightly reductions are ±1.″57 and ±1.″09 in right ascension and ±0.″88 and ±0.″75 in declination. Secular rates in the (0C)'s of Uranus of 0.″029/year in right ascension and ±0.″030/year in declination are present when the observations are reduced with tables. These rates are reduced to 0.″007/year and +0.″015/year, respectively, when nightly reductions are made.
 Publication:

Celestial Mechanics
 Pub Date:
 July 1980
 DOI:
 10.1007/BF01228753
 Bibcode:
 1980CeMec..22...25C
 Keywords:

 Astronomical Coordinates;
 Astronomical Observatories;
 Data Reduction;
 Planetology;
 Reference Stars;
 Stellar Motions;
 Astrometry;
 Celestial Reference Systems;
 Error Analysis;
 Magnitude;
 Position (Location);
 Astronomy