The present study is devoted to the quasi-periodic pulsations (QPPs) in the chromospheric emission of solar flares that are often observed during these phenomena. We analysed the chromospheric emission of an M4.5-class flare (SOL2015-10-01) obtained with the Horizontal-Sonnen-Forschungs-Anlage spectrograph (HSFA-2) at the Ondřejov Observatory of the Czech Academy of Sciences. We also used X-ray time profiles obtained with the Ramati High Energy Solar Spectroscope Imager (RHESSI) and observations in the microwave range obtained with the radio telescope RT3 at 3.0 GHz (Ondřejov Observatory) to test the reliability of the detected chromospheric QPP periods. The processing and analysis of the spectra in the CaII H, Hβ, Hα, and CaII IR 8542 Å lines and the time profiles of the X-ray and microwave emission revealed the presence of oscillation periods in the range of 1-2 minutes.

We present a preliminary analysis of a flare event that took place on 3 June 2021 at 01:36 UT. It was observed in microwaves by the Siberian Radioheliograph (SRH) within 3-6 GHz and by the Broadband Microwave Spectropolarimeter (BBMS), and in the meter-wavelength range by the e-Callisto spectrometer network. We found several type III bursts and a type-J burst in the meterwavelength range. At the same time, only one burst was detected in the averaged time profiles of microwave emission. This one corresponds to the strongest type III radio burst. Using images from the SRH, we defined two sources and separately analysed their time profiles. This approach allowed us to find microwave bursts associated with radio bursts, which were indistinguishable in the averaged time profiles. The observed delays between the microwave and meter-wavelength emissions were compared with the results of a preliminary analysis of dynamic spectra in the meter-wavelength range.