The TESS Input Catalog Version 8 (TIC-8) presented in Stassun et al. (2019) was assembled based on the Gaia DR2 catalog, and augmented with data from many additional catalogs to create a full list of point sources and extended sources that could be observed by TESS. The input catalog data are used to determine the physical and observational parameters of many of the TIC stars, including stellar radius, stellar mass, and effective temperature. TIC-8 includes 1.7 billion point sources and about 100 million extended sources.
TIC-8 is now available at MAST. This includes access via the MAST portal and via bulk downloads. The MAST TESS page has all the information. Data Release Notes for TIC-8 as well as previous versions of the TIC can be found here.
A visual overview of the input catalogs and methodology used to construct the TIC is shown in the schematic below.
Overview of the photometric catalogs used to construct the TESS Input Catalog (TIC). Yellow arrows depict the order that catalogs are cross-matched and/or merged. The final TIC (TIC-8 as of 2019-06-01) is represented by the green box at the upper right. Image Credit: Stassun et al. 2019.