Contributed Talk - Splinter HiRes

Wednesday, 20 September 2017, 15:00   (Auditorium MPS)

Small scale chromospheric fibrils observed by SUNRISE 2

R. Gafeira1, A. Laggr1, S. K. Solanki1, M. van Noort1, S. Jafarzadeh2
1Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
2Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, N-0315 Oslo, Norway

The special observing conditions of the \textscSunrise observatory allow us observations with unprecedented temporal stability and spatial resolution in the UV. During the second scientific flight, a time series of narrow-band intensity images were recorded using the Sunrise Filter Imager (SuFI) in the Ca \textscii H line for approximately one hour at a cadence of 7 seconds. Using this unique data set we used an automatic fibril tracking algorithm to identify and characterise the morphological properties of 598 slender Ca \textscii H fibrils. In addition, the fibril tracking algorithm delivered an average backbone of every fibril allowing us the study of width and intensity oscillations at several positions along the fibril. A wavelet analysis was then applied to these oscillations to compute their periods, phase relations and the phase speeds. We find that a majority of the fibrils exhibit a clear anti-correlation between the width and intensity oscillations which can be interpreted as a sausage mode.