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: http://www.apo.nmsu.edu/35m_operations/35m_manual/General_Information/Standards/Echelle/Standard_Stars_For_ARCES.html
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Last updated 5 November 2003 by JMD
Last link checked 9 October 2003 by JCB
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.