6.8 UVIS Sensitivity

6.8.1 Limiting Magnitudes

Table 6.10 presents the predicted limiting-magnitude performance of WFC3. The calculations are based on optimal extraction of a point source. The limiting ABMAG at a S/N of 10 was calculated for a 1-hour and a 10-hour exposure.

Table 6.10: Limiting-magnitude performance of WFC3 based on on-orbit sensitivity from SMOV4.
The table provides limiting ABMAGs at a S/N of 10 for the indicated WFC3 filters.

Band

Filter

Limiting magnitude in 1 hr

Limiting magnitude in 10 hrs

WFC3

WFC3

WFC3

NUV

F225W

26.7

28.1

U

F336W

27.3

28.7

B

F438W

27.3

28.7

V

F606W

27.9

29.2

I

F814W

27.1

28.4


Chapter 9 gives further details on estimation of exposure times. Current estimates require use of the WFC3 Exposure Time Calculator (ETC), available online.