EGU24-15727, updated on 09 Mar 2024
https://doi.org/10.5194/egusphere-egu24-15727
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Coronal Bright Points observed in the corona and photosphere with SDO and Hinode

Isabella Kraus1 and Philippe Bourdin2
Isabella Kraus and Philippe Bourdin
  • 1Graz, Physics, Solar Physics, Austria (isabella.kraus@uni-graz.at)
  • 2Graz, Physics, Solar Physics, Austria (philippe.bourdin@uni-graz.at)

The exact coronal heating mechanism remains a riddle, but magnetically active regions are known to host coronal loops with extreme-UV emission. But also at much smaller sizes, up to 10 Mm, there are bipolar regions that can be associated with UV emission in coronal bright points (CBPs). We study the statistical properties of CBPs with continuous data from the SDO spacecraft to track the lifetime of CBPs. We use their tracking data to verify that the lower corona co-rotates with the photosphere. In a next step, we aim to reproduce an isolated CBP in a 3D magneto-hydrodynamic (MHD) simulation. To this end, we need observational data to drive the simulation from both, SDO/HMI and Hinode/NFI. As these instruments feature different resolutions and field-of-views, they also detect different levels of small-scale and large-scale magnetic structures in the photosphere. As we know, these magnetic patches are advected from photospheric horizontal motions and create the necessary Poynting flux at the base of the corona. Combining these data from two very different instruments is a task that needs careful overlaying, so that not artificial effects would appear in the MHD simulation. We use a multi-scale overlaying method to enlarge the field-of-view of Hinode with SDO data, to drive the simulation with consistent photospheric magnetic fields. The bottom and top boundaries are fully closed for any mass and heat flows. The output of the simulation will allow us to compute synthetic UV emission maps that we may compare directly to SDO and Hinode observations. With our model we test if the field-line braiding mechanism is sufficient to heat a CPB to the required temperature. We find that loop-like CBPs usually originate from bipolar regions. Weaker magnetic polarities produce fainter and hence cooler CBPs. And the same time, we find that lifetimes of typical CPBs are easily more than 6 hours. This supports the theory that the heating of CBP is mainly based on magnetic energy dissipation through a relatively steady and slow magnetic reconnection process.

How to cite: Kraus, I. and Bourdin, P.: Coronal Bright Points observed in the corona and photosphere with SDO and Hinode, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15727, https://doi.org/10.5194/egusphere-egu24-15727, 2024.