Related papers: Short-term evolution of coronal hole boundaries
Exchange interaction strongly influences the long-range behaviour of localised electron orbitals. It violates the oscillation theorem (creates extra nodes) and produces a power-law decay instead of the usual exponential decrease at large…
We investigate the timescales of evolution of stellar coronae in response to surface differential rotation and diffusion. To quantify this we study both the formation time and lifetime of a magnetic flux rope in a decaying bipolar active…
RHESSI observations of a solar flare showing continuous motions of double hard X-ray sources interpreted as footpoints of magnetic loops are presented. The temporal evolution shows many distinct emission peaks of duration of some tens of…
Quasi-periodic propagating intensity disturbances have been observed in large coronal loops in EUV images over a decade, and are widely accepted to be slow magnetosonic waves. However, spectroscopic observations from Hinode/EIS revealed…
Waves are important for the heating of the solar corona and the acceleration of the solar wind. We have examined a long spectral time series of a southern coronal hole observed on the 25th February 1997, with the SUMER spectrometer on-board…
Knowledge about grain boundary migration is a prerequisite for understanding and ultimately modulating the properties of polycrystalline materials. Evidence from experiments and molecular dynamics (MD) simulations suggests that the…
We present a method that isolates time-varying components from coronagraph and EUV images, allowing sub-streamer transients propagating within streamers to be tracked from the low to high corona. The method uses a temporal bandpass filter…
Recent high-resolution observations of sunspot oscillations using simultaneously operated ground- and space-based telescopes reveal the intrinsic connection between different layers of the solar atmosphere. However, it is not clear whether…
We derive the statistical limit of the spectral autocorrelation function and of the survival probability for the indirect photodissociation of molecules in the regime of non-overlapping resonances. The results are derived in the framework…
We study the link between an expanding coronal shock and the energetic particles measured near Earth during the Ground Level Enhancement (GLE) of 17 May 2012. We developed a new technique based on multipoint imaging to triangulate the 3-D…
We report on the merging between the southern polar coronal hole and an adjacent coronal dimming induced by a coronal mass ejection on 2022 March 18, resulting in the merged region persisting for at least 72 hrs. We use remote sensing data…
Methods. We study an equatorial CH observed simultaneously by HINODE and STEREO on July 27, 2007. The HINODE/SP maps are adopted to derive the physical parameters of the photosphere and to research the magnetic field evolution and…
The observed long-term spin-down evolution of isolated radio pulsars cannot be explained by the standard magnetic dipole radiation with a constant braking torque. However how and why the torque varies still remains controversial, which is…
We apply a new method to determine the magnetic field in coronal loops using observations of coronal loop oscillations. We analyze seven Doppler shift oscillation events detected by SUMER in the hot flare line Fe XIX to obtain oscillation…
Recent observational results for magnetic fields in molecular clouds reviewed by Crutcher (2012) seem to be inconsistent with the predictions of the ambipolar diffusion theory of star formation. These include the measured decrease in mass…
Because of its distinctive compositional properties and variability, low-speed ($\lesssim 450$ km s$^{-1}$) solar wind is widely believed to originate from coronal streamers, unlike high-speed wind, which comes from coronal holes. An…
We present a model for separator reconnection due to an isolated reconnection process. Separator reconnection is a process which occurs in the neighbourhood of a distinguished field line (the separator) connecting two null points of a…
Bald patches are magnetic topologies in which the magnetic field is concave up over part of a photospheric polarity inversion line. A bald patch topology is believed to be the essential ingredient for filament channels and is often found in…
To study the dynamics of coronal holes and the role of waves in the acceleration of the solar wind, spectral observations were performed over polar coronal hole regions with the SUMER spectrometer on SoHO and the EIS spectrometer on Hinode.…
We develop a reliable, fully automatic method for the detection of coronal holes, that provides consistent full-disk segmentation maps over the full solar cycle and can perform in real-time. We use a convolutional neural network to identify…