<Tr> <Th> Alma mater </Th> <Td> Radcliffe College, Oberlin College </Td> </Tr> <Tr> <Th> Known for </Th> <Td> Leavitt's Law: the period--luminosity relationship of Cepheid stars </Td> </Tr> <Tr> <Td_colspan="2"> Scientific career </Td> </Tr> <Tr> <Th> Fields </Th> <Td> Astronomy </Td> </Tr>

Who first mapped the cepheid variable stars for use in determining distance