Naslov
Differences in brightness and size between coronal bright points within coronal holes and quiet Sun regions observed by ALMA

Autori
Matković, Filip

Izvornik
European ARC Newsletter

Vrsta, podvrsta
Ostale vrste radova, ostali članci/prilozi

Godina
2023

Ključne riječi
corona ; coronal bright point ; UV radiation ; plasma ; radio radiation

Sažetak
Coronal bright points (CBPs), being small-scale loops of plasma in the low solar corona connecting concentrations of opposite polarity photospheric magnetic field, are one of the most frequent phenomena in the solar atmosphere. Thanks to ALMA, we can observe and study the properties of legs and footpoints of these bright loop-like structures visible in the solar chromosphere. Using the ALMA single-dish Band 6 observations, Matković et al. (2023) analysed the brightness and area of CBPs within five different coronal holes (CHs) and outside of them in the quiet Sun (QS) regions to find if those properties differ between the CBPs in different regions on the Sun. The analysis of the CBP properties shows that there is indeed a significant difference between the CBPs inside and outside of CHs regarding both of the measured properties. It is found that CBPs within CHs are on average less bright, but also smaller in size than the CBPs outside of CHs. For comparison, a similar analysis is done for the same CBPs visible in the extreme-UV emission observed by the Solar Dynamics Observatory (SDO), which produced results similar to ALMA. Moreover, the analysis also indicates that smaller CHs or CHs with higher abundance of open magnetic field limit the average brightness and size observed by both ALMA and SDO for CBPs within CHs to lower values than those found in the QS regions. The results obtained by Matković and his collaborators clearly show that CBPs are not the same everywhere on the Sun, but rather their appearance is influenced by physical properties of the surrounding region where this influence can be seen in both the solar chromosphere and corona.

Izvorni jezik
Engleski

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