 WASP @-@ 13 was observed between February 11 and 15 in 2008 by the SOPHIE <unk> spectrograph at the <unk> @-@ Provence Observatory in France , determining the radial velocity of the transiting body . Use of the FIES <unk> spectrograph at the Nordic Optical Telescope in the Canary Islands gained other spectral measurements that yielded the characteristics of the star . Analysis of the SOPHIE and FIES data were used to <unk> some of the orbiting body 's characteristics . The discovery of the orbiting body 's mass using radial velocity measurements led to its confirmation as the planet WASP @-@ 13b . 
