The time - amplitude characteristics of the optical variability of NGC 4151 in 1906-1984.
Abstract
The analysis of the photoelectric (1967 - 1984, ≡420 UBV measurements) and photographic (1906 - 1982, ≡560 measurements) observations of the nucleus of the Seyfert galaxy NGC 4151 is carried out. All observations are reduced to a uniform photometric system. The multi-component structure of the light curve is emphasized: there are variabilities with timescales from tens of days to tens of years. All components except the slowest (≡80 years) ones are quasi-periodic, or cyclic. The period search analysis does not show any periodicities from 35 days to 20 years, both for photoelectric (≡18 years) and photographic (≡80 years) observations. Only the first half of the photoelectric set shows the 130-day periodicity (25 cycles). The amplitude of the fast component (the flux) is proportional to that of the slow component.
- Publication:
-
Astronomicheskii Zhurnal
- Pub Date:
- June 1987
- Bibcode:
- 1987AZh....64..465L
- Keywords:
-
- Astronomical Spectroscopy;
- Galactic Nuclei;
- Periodic Variations;
- Radiant Flux Density;
- Seyfert Galaxies;
- Ubv Spectra;
- Amplitudes;
- Astronomical Photography;
- Electrophotometry;
- Light Curve;
- Spectrum Analysis;
- Astrophysics