next previous
Up: Optical astrometry of

4. Notes on individual objects

1236-684: The optical counterpart proposed by Jauncey -for which we give optical coordinates in Table 1 (click here)- is incorrect. This conclusion is sustained by the high (radio-optical) residuals obtained when comparing our optical position for this object with the VLBI radio position given by Johnston (see Table 2 (click here)). As illustrated by Fig. 1 (click here), which shows more or less precisely the position of the radio source, the object proposed by Jauncey lies well offset to the NE of the radio source. At the limit of our plates (tex2html_wrap_inline1033), no faint alternative counterpart is seen. The finding chart and the radio source position identification were obtained using standard IRAF procedures from a digitized image extracted from the Digitized Sky Survey (DSS), produced by the Space Telescope Science Institute. The scan used is based on a 4 min. exposure visual plate taken with the UK Schmidt telescope. The unfortunate fact that this scan is based on a shallow ``supplemental" plate of the UK Schmidt southern sky survey plate collection, prevented us from examining the possible existence of a very faint alternative optical counterpart, at a magnitude level of tex2html_wrap_inline1035 (which is the approximate limiting magnitude of the ``standard" deep blue UK Schmidt survey plates).

  figure237
Figure 2: Finding chart for 2314-409. Chart is 9 arcmin on a side. See Sect. 4 for details

2052-474: The finding chart for this object published by Jauncey is incorrect. A correct identification for the optical counterpart of this source can be found in Murdoch et al. (1984).

2314-409: Identification of the optical counterpart of this source is claimed by Jauncey, but no finding chart has been published. In Fig. 2 (click here) we present a tentative optical counterpart for this source, whose coordinates are given in Table 1 (click here). The finding chart and the optical identification were obtained, as explained for Fig. 1 (click here), from a DSS scan based on a 60 min. exposure UK Schmidt blue plate.


next previous
Up: Optical astrometry of

Copyright by the European Southern Observatory (ESO)
web@ed-phys.fr