This paper is dedicated to the study of variability in active galactic nuclei, which play a key role in understanding the physical processes occurring in their central regions. This research focuses on the analysis of photometric and spectral variability of two Seyfert galaxies, MRK 6 and MRK 1040, based on archival and modern observations. For the first time, the results of photometric observations of MRK 6 have been processed, with special attention given to the profiles of emission lines and the identification of additional spectral components that may indicate gas outflows. The velocity dispersions of each emission-line component have been determined for the studied galaxies. In some profiles of Hα and Hβ, their velocity dispersions and corresponding line-of-sight velocities have been estimated, which may indicate the outflow of matter from the central regions of the galaxies.

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.

Digitized archival astronomical data serve as a valuable resource for studying variable stars and their evolution. This study analyzes variable stars based on archival photometric data obtained with the Schmidt camera at the Fesenkov Astrophysical Institute from 1960 to 1989.Cross-identification with the General Catalog of Variable Stars catalog revealed 20,961 variable stars in the archival frames. Additionally, matching with Gaia DR3 and TESS expanded the characterization of these stars, including galactic height, variability amplitude, spatial distribution, and identification of objects with archival observations. These parameters had not been previously compiled in a single catalog.To further enrich the data, machine learning methods were applied, allowing the classification of objects with incomplete characteristic data and the prediction of their spectral types and variability classes. The analysis demonstrated that XGBoost achieved the highest accuracy among the tested models (78.9% for variability types and 86.46% for spectral types) and identified the most significant parameters influencing stellar variability.The final catalog has been published on the Kazakhstani National Virtual Observatory platform and is available for further research.

This paper presents the architecture of the Kazakhstani National Virtual Observatory (KazVO)—an International Virtual Observatory Alliance (IVOA) compliant node that unifies the heterogeneous observational datasets of the Fesenkov Astrophysical Institute (FAI). The architectural foundation of the system is built upon a partitioned Data Lake, a German Astrophysical Virtual Observatory (GAVO) Data Center Helper Suite (DaCHS) publishing backend, and a PostgreSQL database in which metadata for published observational products are mapped to IVOA ObsCore, while catalogs and simulation grids use dedicated relational tables. We follow Open Science principles by introducing a metadata-only showcase model based on a four-class data embargo mechanism. Machine-to-Machine services deployed via IVOA protocols are exposed through the KazVO publishing registry registered in the global Registry of Registries (RofR), enabling analysis of Kazakhstani observational assets within external clients such as Tool for OPerations on Catalogues And Tables (TOPCAT), Aladin, and PyVO. The current implementation combines operational VO publication services and targeted photometric processing with scheduled, batch-mode data ingestion, supporting access to published historical and modern observational holdings. Replication has been validated on pilot datasets, while routine deployment at the observing sites and automated reduction of modern spectroscopic streams remain under development. The architecture provides a framework for progressively integrating these components into a complete data lifecycle.

(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.