Spectrophotometric Standard Stars For Use With The ARC Echelle Spectrograph (ARCES)

Data from 191 observations of stars with the ARCES were analyzed to calculate exposure times to reach particular signal-to-noise values for bright standard stars. The S/N ratio was normalized in each case by the exposure time, and plotted against the V magnitude of the stars observed; data are shown below:

An exponential fit to the data shows pretty good agreement and allows for forecasting to fainter stars beyond the limit of the data set (V ~ 12). The fit was used to calculate the exposure times in the table below:

All times are given in seconds.