SPECTROPHOTOMETRIC MONITORING OF THE NUCLEUS OF THE GALAXY NGC 4151 AT ITS LIGHT MINIMUM IN 1988

Spectrophotometric monitoring of the nucleus of the galaxy NGC 4151 was carried out for 13 nights from 23 January to 10 June 1988 in the wavelength range 4000-7000 A. A 0.5-m meniscus telescope, a slitless spectrograph, and the highly sensitive, digital television complex of the Crimean Astrophysical Observatory were used. The exposure time was 150-300 see, while the time resolution, allowing for recording spectra of the comparison star, was about 30 min. The results show that the galaxyʹs nucleus was in a deep minimum. On a time scale of days to months, the synthetic magnitudes V(syn) and the fluxes F(con) in the continuum had a similar time dependence; the amplitude of variability reached 15% in January-April, while a brightness increase of 30% was recorded on 13 and 14 May. The time variations of the fluxes in the first (H(3 + [0 III] 4959 A + 5007 A) and second (Halpha + [N II] 6548 A + 6584 A) blends were different.