Preliminary list from Tycho observations (TIC data)
Short Name:
I/207
Date:
21 Oct 2021
Publisher:
CDS
Description:
The selection of the stars of the Tycho program is mainly based on the Tycho input catalogue (TIC), prepared by Egret et al. (1992) from existing ground-based catalogues. The TIC is far to be the definitive list of the stars that will appear in the final Tycho catalogue however. The number of stars included within (3 million) is several times larger than the number eventually expected. The selection of the TIC stars that will remain in the final catalogue is planned in two steps : The former is the "Recognition" that is based on the first year of the scientific mission. The latter step of selection is the final reduction of the Tycho data, which will require a few more years. The recognition was completed in 1992, and, among the 3,154,204 stars of the TIC, about two third were not found in the observations. This catalogue presents the 1,049,971 stars that are still in the programme. The selection is nor definitive, nor complete; but it should contain only a small percentage of stars that will still be discarded. On another side, some stars missing in the TIC have been added to the Tycho program, but the expected number of additional stars to appear in the final catalogue should be about 5 % or less. The list was announced in Halbwachs et al (1994). It is completed with data (coordinates and magnitudes) from the main file of the Tycho Input Catalogue. The cross-identifications with the Hipparcos Input Catalogue or with the INCA database included in catalogue I/197/ are not repeated here.
