Optical variability of Seyfert galaxies

During the period 1979-1993 J.Lub (Leiden University) and I regularly observed a sample of Seyfert galaxies with a number of telescopes at ESO's La Silla Observatory in Chile. The photometry was done using the 90 cm Dutch telescope and the beautiful but unfortunately no longer existing Walraven photometer, while spectroscopy was carried out first with the 3.6 m telescope and in later years with the 1.5 m ESO telescope. Part of the data were published in Astronomy and Astrophysics, in de Ruiter & Lub (1984) and Lub & de Ruiter (1992).
However, the full data set was never published and we decided to make it available through this Web site. You can find a discussion of the data plus an analysis of the photometric and spectroscopic variability of the Seyfert galaxies in this unpublished article. We also give you the opportunity to have a direct look at the data of the individual Seyfert galaxies by clicking one of the names in the right-side list. All individual spectra are shown (usually taken in intervals of about one year), and also an animation showing how the spectrum varies, in the region containing the Hβ and [OIII] lines at rest wavelengths around 5000 Å. All spectra were flux-calibrated; the unit is 10^-14erg s^-1cm^-2Å^-1. The spectra are available on request in either FITS format or as an ASCII file (with two columns, wavelength and flux density), by sending an E-mail to h.deruiter @ ira.inaf.it