A photoelectric BVRI sequence in the field of the globular cluster NGC 6121 (M4) A photoelectric BVRI sequence of eleven stars homogeneously covering thefield of the Galactic globular cluster NGC 6121 (M4) is presented usingdata acquired in the Cousins BVRI photometric system. Three of the starsin the sequence are also on the list of Alcaino and Liller (1984), and acomparison is made with their data. This photometric sequence can beused in the calibration of future observations of NGC 6121 with otherdetectors.
UBV photometry of E region standard stars of intermediate brightness Photometry data are given for 335 stars in the nine E regions.Observations were made using a photometer and filters on the 47 cmreflector at Cape Town. The stellar dispersions are summarized. Data arepresented in tabular form.