Georgia Journal of Science

Article Title

An Eight-Year Photometric Study of the Seyfert 1 Galaxy NGC 5548 **


We present multi-wavelength continuum light curves spanning the period 2012 to 2020 for the Seyfert 1 galaxy NGC 5548. CCD observations in the B, V, R, and I photometric bands (using Johnson/Cousins or Bessel filters) were made with the telescopes operated by the Southeastern Association for Research in Astronomy (SARA) in Arizona, in Chile, and on the island of La Palma. Our observations show that NGC 5548 brightened by one-half to one magnitude (depending upon the filter) during the period 2012 to 2014, followed by a three-year period of dimming. During 2019 the galaxy exhibited a period of rapid brightening. The data show a correlation between brightness (V) and color (V-I), though with significant scatter. These observations will contribute to ongoing reverberation mapping studies of NGC 5548, with the goal of determining the mass of its central back hole (estimated at 5.3±1.7×107 solar masses) and the geometry of the surrounding gaseous regions.

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