Kevin P. Reardon

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Recently, De Pontieu et al. (2007b) discovered a class of spicules that evolves more rapidly than previously known spicules, with rapid apparent motions of 50–150 km s −1 , thickness of a few 100 km, and lifetimes of order 10–60 seconds. These so-called type II spicules have been difficult to study because of limited spatio-temporal and thermal resolution.(More)
Context. The exact nature of the quiet solar chromosphere, and especially its temporal variations, are still subject of intense debate. One of the contentious issues is the possible role of magnetic field in structuring the quieter solar regions. Aims. We characterize the dynamics of the quiet inter-network chromosphere by studying the occurrence of(More)
Following its commissioning in 2019, the Daniel K. Inouye Solar Telescope (DKIST) will be the flagship facility for astrophysical investigations of the full solar atmosphere. The telescope is planned to acquire large volumes (5 PB per year, initially) of heterogeneous data over several decades using several different instruments. We discuss the challenges(More)
Context. Filtergrams obtained in Ca II H, Ca II K and Hα are often employed as diagnostics of the solar chromosphere. The vastly disparate appearance between the typical filtergrams in these different lines calls into question the nature of what is actually being observed. Aims. We investigate the lack of obvious structures of magnetic origin such as(More)
There are significant advantages in combining Hinode observations with ground-based instruments that can observe additional spectral diagnostics at higher data rates and with greater flexibility. However, ground-based observations , because of the random effects of weather and seeing as well as the complexities data analysis due to changing instrumental(More)
Individual X ? ray photons in the keV energy range produce hundreds of photoelectrons in a single pixel of a CCD array detector. The number of photoelectrons produced is a linear function of the photon energy, allowing the measurement of spectral information with an imaging detector system. The Yohkoh Soft X ? ray Telescope uses a CCD in an integrating mode(More)
We provide evidence for the existence of a new type of soft X-ray (SXR) brightening event that we call coronal flashes. The phenomenon was observed on deep time series taken with the SXT of Yohkoh in the north polar coronal hole, near the sunspot minimum. Events last as short as 1.5 mn and the corresponding SXR flux span the range of energies, from single(More)
We investigate the effects of atmospheric dispersion on observations of the Sun at the ever-higher spatial resolutions afforded by increased apertures and improved techniques. The problems induced by atmospheric refraction are particularly significant for solar physics because the Sun is often best observed at low elevations, and the effect of the image(More)
Laser ablation interfaced with inductively coupled plasma-mass spectrometry is described as a new method to determine the presence of phosphorylated proteins on electrophoresis gel blots. The method was applied to the phosphoprotein beta-casein with good detection levels being observed at 16 pmole. Attempts at using the technique to detect beta-casein on(More)
PURPOSE Vaginal packing for gynecological brachytherapy is used to immobilize the applicator and reduce doses to the bladder and rectum by increasing the separation from the applicator. With the introduction of theRadiadyne Alatus™ balloon packing system, we evaluate further reductions in dose to these structures by increasing the concentration of contrast(More)