Vector magnetic fields, obtained separately from the HMI and from the Stokes parameters of Hinode, are compared for a sunspot umbra, penumbra, and plages in a selected active region.
Magnetic field changes associated with solar flares, observed by the SDO/HMI, are surveyed, and permanent changes of magnetic field are found in the majority of flare events. Properties of the magnetic field changes are further investigated.
The dipole, quadrupole, and octupole components of the Sun’s magnetic field are calculated and visualized, covering the last 22 years of the Sun’s activities.
Helioseismic far-side images are compared with the STEREO-AIA EUV observations, and a reliability of the helioseismic images is assessed.
An X9.3 flare excited strong yet unusual sunquakes.
Through analyzing a suite of space- and ground-based observations, the authors report that above sunspots, helioseismic waves of different frequencies are able to channel up through the chromosphere and transition region into corona. General pictures of how the waves make into corona are also shown.
We observed magnetoacoustic waves propagating along the magnetic field lines of a sunspot. Based on the wave periods and atmospheric characteristics, we reconstructed the magnetic field topology of the sunspot.
Multiple-wavelength high-resolution observations reveal running penumbral waves in the middle photosphere, with an apparent horizontal speed of up to 51 km/s.
A newly discovered, fast-moving wave propagates outward along sunspots’ radial direction and may provide new diagnostics of the sunspot subsurface structure.
Numerical simulation of sunspots indicate that different subsurface structures are possible. They may be deep coherent flux tubes or twisted spaghetti or shallow structures. It may well be that all the models proposed for sunspot structures are correct for some spot somewhere.