Scientific results

The significant brightening of the flat spectrum radio quasar OP 313 (BZU J1310+3220, 4FGL J1310.5+3221) was recently been reported in gamma-ray (ATel #17167), near-infrared (ATel #17179) and optical bands (ATel #17173, #17184, #17185) over the past two weeks. read more →

In 2024 the enhanced gamma-ray activity from 3C 138, also known as 4FGL J0521.2+1637, was observed with the Fermi/LAT (Large Area Telescope) (ATel #16845). read more →

The KM3NeT experiment reported the detection of an ultra-high-energy neutrino with an energy estimate of ~ 220 PeV, the most energetic yet observed.  read more →

During current long-term monitoring of microquasars we have detected the bright flare from the microquasar GRS1915+105 with the RATAN-600 radio telescope. read more →

read more →

Analysis of more than 300 M-class solar flares observed with the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory in the 131 Å channel, revealed 16 events of sloshing oscillations in hot solar coronal loops. read more →

The existence of continuous cooling and heating processes is an important condition governing the behavior of the solar corona, which is characterized by temperatures of several million Kelvin. These processes can be significantly influenced by small-scale coronal formations, which largely determine the thermal balance of the corona and solar-wind disturbances.  read more →

Blazars are beamed active galactic nuclei (AGNs) known for their strong multi-wavelength variability on timescales ranging from years down to minutes. Many different models have been proposed to explain this variability. read more →

We present a study of the multiwavelength (MW) variability of the blazar AO 0235+164 based on the radio-to-γ-ray data covering a long time period from 1997 to 2023. The radio data are represented by the 1-22 GHz measurements from the SAO RAS RATAN-600 radio telescope, the 5 and 8 GHz data from the IAA RAS RT-32 telescopes, and the 37 GHz data from the RT-22 telescope of CrAO RAS. read more →

The flat-spectrum radio quasar PKS 2126-15, located at z=3.26, has been identified as one of the first high frequency peaker (HFP) objects with a maximum in its radio spectrum around 8 GHz. It is represented in the BLcat catalogue of blazars monitored with the RATAN-600 radio telescope at 1.2-22.3 GHz since the 2000s. read more →

When observing the Sun with RATAN-600 radio telescope using a spectropolarimetric complex in the range 1–3 GHz, as well as when observing coronal rain, absorption in the radio emission was discovered in the spectral region 1.5–1.65 GHz in active solar regions located under a cold filament or on the limb under a prominence. read more →

We present the first X-ray spectropolarimetric results for Cygnus X-1 in its soft state from a campaign of five IXPE observations conducted during 2023 May–June. read more →

We continue the long-term multi-frequency monitoring of the Galactic microquasars with the RATAN-600 radio telescope almost daily in 2024 at 1.24-30 GHz. read more →

We present Very Long Baseline Array observations of radio continuum and OH line emission toward the OH megamaser (OHM) galaxy IRAS 01298−0744. read more →

In February 2023 we reported the historical high flux density level of the flat-spectrum radio quasar Ton 599 (4C +29.45) at 1.2-36.8 GHz (ATel #15894).  read more →

The accretion of matter by compact objects can be inhibited by radiation pressure if the luminosity exceeds a critical value known as the Eddington limit. read more →

The flux density spectra of cyclotron sources above the sunspots were obtained by observations with RATAN-600 in the range of 1.7–10 cm with high spectral resolution and their spectral indices were estimated.  read more →

The article discusses the prospects for developing the observational base at the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) for astrophysical research in the millimeter-wave range.  read more →

The results of the analysis of 205 brightest sources, which were found in the sky survey at the declination of the pulsar in the Crab Nebula, are presented. read more →

We present a study of the radio variability of bright, S1.4≥100 mJy, high-redshift quasars at z≥3 on timescales of up to 30–40 yrs. The study involved simultaneous RATAN-600 measurements at the frequencies of 2.3, 4.7, 8.2, 11.2, and 22.3 GHz in 2017–2020.  read more →

We carry out the long-term multi-frequency monitoring of the Galactic microquasars with the RATAN-600 radio telescope almost daily in 2024 at 1.24-30 GHz. We have detected the activity from the microquasar Cygnus X-3 on 27 March after the long period of the very low hard X-ray state at 15-50 keV, named by a hyper-soft state, as according to the Swift/BAT public domain data. read more →