Table B.2
Summary statistics for the 361 million sources in Gaia DR2 with a fall-back solution (position only).
| Median value at magnitude G | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Quantity | ≤ 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | Unit |
| Fraction of sources with fall-back solution | 0.9 | 1.0 | 1.0 | 1.0 | 1.1 | 1.4 | 2.4 | 5.5 | 17.1 | 84.1 | % |
| Standard uncertainty in α (σα*) at J2015.5 | 0.905 | 0.968 | 0.972 | 0.970 | 0.989 | 1.018 | 1.036 | 1.518 | 2.204 | 3.623 | mas |
| Standard uncertainty in δ (σδ) at J2015.5 | 0.876 | 0.924 | 0.931 | 0.921 | 0.936 | 0.956 | 0.971 | 1.399 | 1.897 | 3.387 | mas |
| Number of visibility periods used | 10 | 11 | 11 | 10 | 9 | 8 | 7 | 6 | 6 | 6 | |
| Number of field-of-view transits used | 16 | 19 | 19 | 18 | 15 | 13 | 11 | 9 | 9 | 8 | |
| Number of good CCD observations AL | 133 | 161 | 158 | 149 | 130 | 107 | 96 | 79 | 78 | 62 | |
| Fraction of bad CCD observations AL | 2.7 | 0.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | % |