Notes. The columns indicate the star names and types as listed in the SIMBAD database (Wenger et al. 2000), their Gaia DR2 match and the respective calibrators that were observed. In order to be able to distinguish the calibrators better in future work, they were also assigned variables – P 1, P 2, S 1, and S 2. For each star, the experiment(s) (see Table E.2), the frequency band, and the reference providing the a priori position used for scheduling are given as well. In the case that two references are given, the first one describes the original data and the second one points to improved data as given in the respective reference. In this case the improved data were used. An ellipsis (…) indicates the omission of an entry. ⁽¹⁾Not in ICRF3. The position in rfc_2018b (given in the format of (α,δ)) is (49.120883046°±0.36 mas, 27.552263 194°±0.45 mas) for J0316+2733, (65.263 952933°±0.37 mas, 26.110 132 133°±0.48 mas) for J0421+2606, (85.340 401 167°±0.15 mas, -2.185 662947°±0.29 mas) for J0541-0211, (227.727 671 113°±0.21 mas, -8.722588583°±0.46 mas) for J1510-0843, (241.192478767°±1.96 mas, 67.371 391 931°±0.66 mas) for J1604+6722, (316.431 623 725°±0.67 mas, 29.347 996 394°±0.77 mas) for J2105+2920, (331.789 686 825°±0.23 mas, 43.274 276 806°±0.28 mas) for J2207+4316.⁽²⁾ Also known as HR 1099.

References. (1) Boboltz et al. (2007); (2) Lestrade et al. (1999); (3) Lindegren (2020a); (4) Torres et al. (2012); (5) Galli et al. (2018); (6) Torres et al. (2007); (7) Loinard et al. (2007); (8) Torres et al. (2009); (9) Kounkel et al. (2017); (10) Ortiz-Leon et al. (2017b); (11) Miller-Jones et al. (2013).