WARNING: This page has not been updated since the Wide Field Upgrade and is no longer maintained.
Please see the updated Observing Statistics page here: https://hydra.as.utexas.edu/?a=help&h=22
The following table are not HET skybrightness values and
represent very clear
sky dark site magnitudes. The HET is currently performing worse than these
numbers but we keep them listed here for reference.
DO NOT USE THE THEORETICAL SKY BRIGHTNESS NUMBERS
The table above can be used to judge how lunar phase and different band passes
will interrelate. The R and I band passes are dominated by the bright OH
emission lines so the sky brightness is less affected by the scattered moon
light.
Theoretical Sky Brightness Data
Moon Phase
days from newB V R I
0 (dark) 22.7 21.8 20.9 19.9
3 22.4 21.7 20.8 19.9
7 (grey) 21.6 21.4 20.6 19.7
10 20.7 20.7 20.3 19.5
14(full) 19.5 20.0 19.9 19.2