This paper presents the results of the photometric and spectral monitoring of the galaxy NGC 3516, which is an active galactic nucleus (AGN) of type Sy $1.5$ with a changing look. Observations were carried out at the Fesenkov Astrophysical Institute (FAI, Almaty, Kazakhstan) and the Shamakhy Astrophysical Observatory (ShAO, Shamakhy, Azerbaijan). Spectral monitoring of this galaxy in the wavelength range 4000–7000 Å began in 2020, while photometric observations have been conducted since 2014. During the observation period, estimates of the galaxy’s brightness in the B, V and $Rc$ filters were obtained, as well as measurements of the emission line and continuum fluxes. The light curve shows increased brightness of NGC 3516 in 2016 and 2019. The increase of emission line fluxes of H$\beta$ and H$\alpha$ and continuum began in 2019 and continued until spring 2020, when these characteristics reached their maximal values. A powerful X-ray flare took place on 1 April 2020. A new phase of brightening began in 2021 and has continued until 2025. After reaching their maxima in 2020, the emission fluxes of H$\beta$ and H$\alpha$ decreased by a factor of 1.5–2 and remained at a low level until 2022–2023, when they began to increase again. Medium-resolution spectra obtained on 20 April 2020, with the 1-meter “West” telescope (TSHAO) were used to study the broad components of the H$\beta$ and H$\alpha$ emission line profiles. Model calculations showed that the broad profile of the H$\alpha$ line consists of a central unshifted component and two (blue and red) components shifted symmetrically relative to the central component by a velocity of $v=980\pm 20$ km ${\mathrm{s}}^{-1}$. The H$\beta$ emission line was relatively weak, so the radial velocity of its components was determined with a large uncertainty: $900\pm 600$ km ${\mathrm{s}}^{-1}$.

The galaxy NGC 7469 is a bright infrared source with an active galactic nucleus (AGN) and an intense star-forming region with a radius of approximately 500 parsecs, where the star formation rate is estimated to be 20–50 $M_{\odot }{\mathrm{yr}}^{-1}$. This study presents the results of spectral and photometric observations carried out during the period from 2020 to 2024 at the Fesenkov Astrophysical Institute (Almaty, Kazakhstan) and the Nasreddin Tusi Shamakhy Astrophysical Observatory (Shamakhy, Azerbaijan). Photometric data were obtained using B, V, and Rc filters, while spectroscopic observations covered the wavelength range of $\lambda$ 4000–7000 Å. Data reduction was performed using the IRAF and MaxIm DL Pro6 software packages. An analysis of the light curves revealed that after the 2019–2020 outburst, the luminosity level of NGC 7469 remained relatively stable until the end of 2024. In November–December 2024, an increase in brightness (∼0.3–0.5 magnitudes) was recorded. Spectral data show variations in the Ha fluxes and an enhancement of them at the end of 2024. On BPT diagrams, the emission line flux ratios [OIII]/H $\beta$ and [NII]/H $\alpha$ place NGC 7469 on the boundary between regions dominated by different ionization sources: AGN and star-forming regions. The electron density of the gas, estimated from the intensity ratios of the [SII] 6717, 6731 Ålines, is about $900–1000{\mathrm{cm}}^{-3}$. Continued observations will help to determine whether the trend of increasing brightness and emission line fluxes recorded at the end of 2024 will persist.

(1) Background: NGC 3516 is an active Seyfert galaxy, which has become a focal point of astronomical studies due to its variable luminosity and emission lines, linked to the activity of its central supermassive black hole (SMBH). This paper presents an analysis of long-term observations from 2014 to 2024, including photometric and spectroscopic data collected at the Fesenkov Astrophysical Institute (FAI, Kazakhstan) and the Shamakhy Astrophysical Observatory (SHAO, Azerbaijan). The primary aim of this study was to investigate the changes in luminosity and spectral characteristics of NGC 3516, providing insights into the dynamics of the galaxy’s activity and its evolving chemical composition. (2) Methods: The research utilized photometric data in the B, V, R filters, along with spectroscopic observations in the wavelength range of λ4000 Å–λ7000 ÅThe spectroscopic data were normalized to analyze the profiles of emission lines and their variations over time. Broad emission line profiles (Hα and Hβ) were also analyzed to estimate radial velocities. A three-component model was applied, demonstrating a better statistical fit to the observed data, indicating a complex structure and dynamics within the galaxy’s Broad Line Region (BLR).; (3) Results: The main results of the study show that from 2018 to 2024, the brightness of NGC 3516 varied with amplitudes of ΔB=0.35 mag, ΔV=0.18 mag, ΔR=0.20 mag. An increase in brightness was observed in April 2020, likely associated with an X-ray flare detected simultaneously. Spectroscopic observations revealed a gradual weakening of the Hγλ4340 Å emission line starting from mid-2023. Narrow emission lines of [FeII] λ4814.53 Å and [FeVII] λ6087 Å were detected, indicating an active phase of the galaxy in May 2020. Photometric observations also revealed an increase in the object’s brightness in 2020. These observations suggest intriguing changes in the object’s activity, potentially indicating luminosity and chemical composition dynamics over the observed period. For the broad Hα line profile in the spectrum of NGC 3516, obtained with the AZT-8 on April 20, 2020, the radial velocity v=981−20+19 km/s. The radial velocity for the Hβ profile was 937−576+584 km/s; (4) Conclusions: Long-term observations of NGC 3516 have revealed significant changes in its luminosity and spectral characteristics, suggesting dynamic processes within the active nucleus of the galaxy. The observed variability in the broad emission line profiles could be linked to processes within the Broad Line Region (BLR) interacting with the SMBH and surrounding matter. These results may help in a more accurate estimation of the SMBH mass and provide deeper insights into the dynamics and evolution of active Seyfert galaxies.

We present the results of long-term photometric and spectroscopic monitoring of the Seyfert galaxy NGC 4151 based on new observational data complemented by archival material spanning several decades. NGC 4151 is one of the most extensively studied active galactic nuclei, exhibiting pronounced variability in both optical continuum and emission-line fluxes, which makes it a key object for investigating physical processes in the central engine and the broad-line region. Our study covers the optical and near-infrared wavelength ranges, including the Ic band and the standard BVRc photometric filters. Using multi-band optical photometry and optical spectroscopy, we construct light curves of the continuum and emission lines and perform a comparative analysis of their temporal behavior during different activity states of the galaxy. The analysis focuses on variability amplitudes, long-term trends, and correlations between photometric and spectral characteristics, allowing us to examine the relationship between continuum variations and the line-emitting regions.

In this work, the light curve of the Seyfert galaxy Mrk 6 constructed from photometric observations in the B, V, and Rc filters over the period from 5 April 2016 to 1 February 2026 is presented and analyzed. Over the entire monitoring interval (2016–2026), the variability amplitude of the light curve reaches ΔB=1.9 mag, ΔV=1.5 mag, and ΔRc=1.4 mag. During 2024–2026, the galaxy exhibits synchronous photometric variability in the B, V, and Rc filters with an amplitude of ∼0.3 mag. The study also uses spectroscopic observations obtained on 15 and 22 November 2025 and 16 February 2026 at the Shamakhy Astrophysical Observatory (Azerbaijan), as well as on 9 January 2026 at the Fesenkov Astrophysical Institute (Kazakhstan). The fluxes of the Hβ emission line were calibrated using the [O III] λ5007 Å line, ensuring consistent relative calibration of the spectral data. The radius of the broad-line region RBLR was taken to be equal to the average time delays (lags), amounting to ≈20 light-days for the Hβ line and ≈28 light-days for the Hα line.

The galaxy NGC 7469 is a bright infrared source with an active galactic nucleus (AGN) and an intense star-forming region with a radius of approximately 500 parsecs, where the star formation rate is estimated to be 20–50 M⊙yr−1. This study presents the results of spectral and photometric observations carried out during the period from 2020 to 2024 at the Fesenkov Astrophysical Institute (Almaty, Kazakhstan) and the Nasreddin Tusi Shamakhy Astrophysical Observatory (Shamakhy, Azerbaijan). Photometric data were obtained using B, V, and Rc filters, while spectroscopic observations covered the wavelength range of λ 4000–7000 Å. Data reduction was performed using the IRAF and MaxIm DL Pro6 software packages. An analysis of the light curves revealed that after the 2019–2020 outburst, the luminosity level of NGC 7469 remained relatively stable until the end of 2024. In November–December 2024, an increase in brightness (∼0.3--0.5 magnitudes) was recorded. Spectral data shows variations of the Ha fluxes and an enhancement of them in the end of 2024. On BPT diagrams, the emission line flux ratios [OIII]/H β and [NII]/H α place NGC 7469 on the boundary between regions dominated by different ionization sources: AGN and star-forming regions. The electron density of the gas, estimated from the intensity ratios of the [SII] 6717, 6731 Å lines, is about 800--900cm−3. Continued observations will help to determine whether the trend of increasing brightness and emission line fluxes recorded at the end of 2024 will persist.