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Observations of Alfvén Waves Simultaneously in Hα and K

Published online by Cambridge University Press:  04 August 2017

Ronald G. Giovanelli
Affiliation:
CSIRO Division of Applied Physics, Sydney, Australia 2070
Jacques Beckers
Affiliation:
MMTO, University of Arizona, Tucson, AZ 85721

Extract

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Simultaneous spectroheliograms of a quiet region at solar disk centre in Hα + 0.29 Å, Hα − 0.29 Å, K + 0.18 Å and K − 0.18 Å show much similarity in the asymmetries in the two lines. The fibrils are identical geometrically. Both lines show patterns of line-of-sight motions propagating along the fibrils. Close to the network, the velocity of propagation is of the order of 12 km s−1 towards or away from the network; further away the patterns propagate away from the network at velocities of the order of 75 km s−1. The latter are interpreted as Alfvén waves, the former as due most likely to variations in longitudinal velocities along the fibrils.

Type
IV. The Role of Magnetic Fields in the Structure and Energy Balance of Stellar Atmospheres
Copyright
Copyright © Reidel 1983 

References

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