At the end of September 2017 the private researchers Andreas Kerpe and Stefan Kiefer have been visiting Hessdalen. Their trip has taken place simultaneously with the Norwegian Science Camp. The mountain slope south of Slettælet parking place has been the preferred observing location.
During the night from September 23rd to 24th the two researchers could observe a light in northern direction. Within five minutes three different light phenomena appeared against the backdrop of mount Rogne. During the period of observation two smartphones showed a divergence of the compass needle. No photography of the phenomenon has been taken. The full report is linked here.
Sketch of the phenomenon observed