moustakas
commented
1 year ago I spot-checked a few of these and they all appear to be in Gaia/DR3, as expected.
Closed djschlegel closed 1 year ago
moustakas
commented
1 year ago I spot-checked a few of these and they all appear to be in Gaia/DR3, as expected.
Gaia DR2 is missing a small fraction bright stars, estimated below at 0.1% at high galactic latitude.
Here are the 14 stars brighter than r<15 in the dr9k/south footprint (211<RA<224, -2.2<Dec<+3.2) that do not appear in Gaia DR2 or Tycho: RA DEC RMAG 218.71291 -1.9855050 11.5572 223.10731 -1.6254363 11.6590 218.20799 0.59496147 11.7218 222.59273 2.4263086 11.9684 212.24298 -1.9552306 12.8134 223.21928 -1.6003057 12.9087 222.47002 -1.8524959 12.9898 219.45889 2.1466384 13.5762 212.17080 -2.1165295 13.6551 223.90142 -0.65077887 14.0175 213.04258 -0.58345320 14.1541 220.95946 -0.21198312 14.3760 217.23681 1.0620780 14.5188 214.42220 0.32726449 14.8478
Here are the 13 stars brighter than r<15 in the dr9k/north footprint (214<RA<231, 40.5<Dec<46.5) that do not appear in Gaia DR2 or Tycho: RA DEC RMAG 220.96619 45.014081 11.8365 227.86704 44.403692 12.7738 220.53316 44.357108 13.0580 221.87186 44.552362 13.3808 225.81938 44.289786 13.6889 221.81416 44.324216 13.8839 226.27729 41.301193 14.2587 229.97264 42.589867 14.2768 226.97405 42.824330 14.3270 221.51410 44.111218 14.4453 229.93129 43.410316 14.6093 222.68704 45.600076 14.6938 215.58308 41.947994 14.7545
The prevalence of these missing Gaia sources at r<15 is therefore 14 of 17470 in the south (1092 bricks), 13 of 11129 in the north (935 bricks), or about 0.1% and one per 4 sq deg at high galactic latitudes.
Presumably, Gaia DR3 will recover this small fraction of missing bright stars. Tractor does find them, so this isn't necessarily a problem for us, but it's interesting to see what bright things are on the sky that do not appear in these catalogs.