Spectrophotometry is presented for 237 stars in 7 nearby open clusters : Hyades , Pleiades , Alpha Persei , Praesepe , Coma Berenices , IC 4665 , and M39 .
The observations were taken by Lee McDonald and David Burstein using the Wampler single-channel scanner on the Crossley 0.9m telescope at Lick Observatory from July 1973 through December 1974 .
Sixteen bandpasses spanning the spectral range 3500 \AA to 7780 \AA were observed for each star , with bandwidths 32 \AA , 48 \AA or 64 \AA .
Data are standardized to the Hayes–Latham system to mutual accuracy of 0.016 mag per passband .

The accuracy of the spectrophotometry is assessed in three ways on a star-by-star basis .
First , comparisons are made with previously published spectrophotometry for 19 stars observed in common .
Second , ( B–V ) colors and uvby colors are compared for 236 stars and 221 stars , respectively .
Finally , comparsions are made for 200 main sequence stars to the spectral synthesis models of Kurucz , fixing log g = 4.0 and [ Fe/H ] = 0.0 , and only varying effective temperature .
The accuracy of tests using uvby colors and the Kurucz models are shown to track each other closely , yielding an accuracy estimate ( 1 \sigma ) of 0.01 mag for the 13 colors formed from bandpasses longward of the Balmer jump , and 0.02 mag for the 3 colors formed from the three bandpasses below the Balmer jump .
In contrast , larger scatter is found relative to the previously published spectrophotometry of Bohm-Vitense & Johnson ( 16 stars in common ) and Gunn & Stryker ( 3 stars ) .

We also show that the scatter in the fits of the spectrophotometric colors and the uvby filter colors is a reasonable way to identify the observations of which specific stars are accurate to 1 \sigma , 2 \sigma , \ldots .
As such , the residuals from both the filter color fits and the Kurucz model fits are tabulated for each star where it was possible to make a comparison , so users of these data can choose stars according to the accuracy of the data that is appropriate to their needs .

The very good agreement between the models and these data verifies the accuracy of these data , and also verifies the usefulness of the Kurucz models to define spectrophotometry for stars in this temperature range ( > 5000 K ) .
These data define accurate spectrophotometry of bright , open cluster stars that can be used as a secondary flux calibration for CCD-based spectrophotometric surveys .