Tod started the afternoon session with a detailed overview of the fascinating oscillations seen during giant flares on magnetars. In the two objects where these oscillations have been seen, a wide range of frequencies have been detected. It is highly suggestive that these are torsional oscillations due to vibrations in the crust.
With further understanding and detections there is the exciting possibility to constrain neutron star properties from these oscillations. As Tod discussed, there are still a number of theoretical issues, and lots of complexity in the observations. For example, does the crust fracture (analogy to earthquake fractures)? And, while what we observe are modulations in X-ray flux - can these actually be produced by crust motions?
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