Former German ski star Felix Neureuther has paid tribute to his mother, two-time Olympic champion Rosi Mittermaier, in an emotional message on social media. Mittermaier died on Wednesday at age 72 and her son took to Instagram late Saturday, posting a photo showing him as a little boy looking up into the sky together with his mother. The caption read: “You showed me the stars. Now you are one yourself.Thank you for everything dear mum.” His wife, former biathlete Miriam Neureuther, added in the comments: “The brightest star.” Mittermaier won downhill and slalom gold as well as giant slalom sil…