Model image of Cepheid L Carinae

Two model images of the Cepheid star L Carinae as deduced from the interferometric observations: in the near-infrared from VINCI measurements (left) and in the mid-infrared from MIDI (right). In both cases, an envelope is found to surround the star. The contribution from the envelope is about 5% in the near-infrared and significantly more in the thermal infrared. As L Carinae is 17,000 times brighter than the Sun, this means that its envelope alone is several hundred times brighter than our Sun!