Waves and Quasi-Periodic-Pulsations in Weak Active Solar Emissions

<p>The presence of Quasi-periodic pulsations (QPPs) is found to be a common feature of flaring energy release processes on the Sun. They are observed all across the EM range from hard X-rays to radio and provide insights into the physical conditions in the coronal plasma and the processes involved in the generation of these waves and oscillations. There have been numerous observations of spatially resolved QPPs at higher energies, though there are fewer examples at radio frequencies. Spatially resolved observations of these phenomena are particularly rare at low radio frequencies and there are none which are associated with the weaker episodes of active emissions which are much more numerous and frequent. The key reason limiting such studies has been the lack of availability of spectroscopic snapshot images of sufficient quality to detect and characterise the low level changes in the morphology of the sources of active emissions. Together, the data from the Murchison Widefield Array (MWA), a SKA precursor, and an imaging pipeline developed to meet the specific needs of solar imaging, now meet this challenge and enable us to explore this rich and interesting science area. Our work has led to the discovery of several previously unknown phenomena - second-scale QPPs in the size and orientation of a type III source, with simultaneous QPPs in intensity; 30 s QPPs in the radio light curve of a type I emission source associated with active region loop hosting a transient brightening; and intermittent presence of an anti-correlation in the size and intensity of a type I noise storm source along with QPPs. In this presentation we will briefly summarise these recent results and discuss their implications.</p>

An Analysis of Eruption of the Sun Detected by Solar Radio Burst Type I

Type I solar burst were identified based on data recorded by CALLISTO BLEIN, Switzerland in the period of 17th of January, 2011. Solar Radio Burst Type I is one of the main type of solar burst which is believed to provide a diagnostic of electron acceleration in the corona. This noise storm burst is associated with emerging and growing active regions and last from hours to days. It can be observed that solar radio burst type I is formed within four minutes, although the number of sunspots is just 15. The results of the recent time indicate that Sunspot group 1147 has been mostly quiet since it rounded the eastern limb, but previous week's far side activity shows it is capable of significant eruptions. In 2011, only one day has been detected with spotless day, which means that it is about 7% of overall cases. Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm. From the current conditions in the space weather website on 16th January 2011 that is the first event was shown that the solar wind occurred with a speed of 433.2 km/second while its density about 3.2 protons/cm3. Besides the solar wind, X-ray solar flare with 6 hours maximum: B1 at 1846 UT and 24 hours: B2 at 1544 UT were detected. While type I seem to be an indicator of pre-solar flare and CMEs, on the observational analysis, we could not directly confirmed that this is the only possibility, and we need to consider other processes to explain in detailed the injection, energy loss and the mechanism of the acceleration of the particles. We could conclude one active region will not produce a huge explosion of solar phenomena.