3 Results

From Feb. 1992 to Mar. 1997, there are 69 radio stars to be observed with the photoelectric astrolabe. Using the data, the radio star catalogue observed in San Juan (RSSJ95) has been compiled from double transits of given radio stars at both eastern and western passages. The mean number of observations of each star is about 132 (63 in the eastern passage, 69 in western passage). The mean precisions are $\pm$2.2 ms and $\pm0.035''$ in right ascension and declination, respectively.

The Radio star catalogue observed in San Juan is given in Table 1. The description of each column is:

1:

INCA: star number in the proposals of radio stars submitted to the Input Catalogue Consortium of Hipparcos;

2:

HD: HD number;

3:

SAO: SAO number;

4:

Mag: visual magnitude;

5:

Sp: spectral type;

6:

$\alpha_{2000}$: right ascension referred to equinox J2000.0 at observation epoch;

7:

$\sigma_{\alpha}$: mean errors of position in right ascension in unit of 0.001$^{\rm s}$;

8:

$\delta_{2000}$: declination referred to equinox J2000.0 at observation epoch;

9:

$\sigma_{\delta}$: mean errors of position in declination in unit of 0.01'';

10:

$N_{\rm e}$: number of observations in the eastern transit;

11:

$N_{\rm w}$: number of observations in the western transit;

12:

Epoch: mean epoch of observations.

There are 68 radio stars commented RSSJ95 and the Hipparcos catalogue provided by CDS at nearly identical observational epochs. So we try to do a comparison between respective positions after reducing to the epoch of the Hipparcos catalogue, 1991.25, using the proper motions of the Hipparcos catalogue. The differences in the sense (Hipparcos - RSSJ95) are shown in Table 2.

In Table 2, the columns are as follows:

1:

INCA: star number in the proposals of radio stars submitted to the Input Catalogue Consortium of Hipparcos;

2:

HIP: number in Hipparcos catalogue;

3:

$\alpha_{\rm hip}$: right ascension of Hipparcos catalogue referred to equinox J2000.0 at epoch 1991.25;

4:

$\delta_{\rm hip}$: declination of Hipparcos catalogue referred to equinox J2000.0 at epoch 1991.25;

5:

$\alpha_{\rm rssj}$: right ascension of RSSJ95 referred to equinox J2000.0 at epoch 1991.25;

6:

$\delta_{\rm rssj}$: declination of RSSJ95 referred to equinox J2000.0 at epoch 1991.25;

7:

$\Delta\alpha$: the difference in right ascension (HIP-RSSJ95) in unit of 0.001$^{\rm s}$;

8:

$\Delta\delta$: the difference in declination (HIP-RSSJ95) in unit of 0.01''.

  

Table 1: Radio star catalogue observed in San Juan

 

Table 1: continued

  

Table 2: The difference of positions (HIP-RSSJ95)

 

Table 2: continued