In NUMBER@1 astronomers PERSON@1 , PERSON@2 , and Soon reported measurements of a sample of stars ' Calcium II H and K spectral lines and thereby measured a rotational period of NUMBER@2 days for NUMBER@3 Pegasi .

In NUMBER@1 astronomers PERSON@1 , PERSON@2 , and Soon calculated that it takes NUMBER@3 PERSON@3 b NUMBER@2 days to orbit NUMBER@3 Pegasi .
