<Tr> <Th> Apparent magnitude </Th> <Td> 13.65 to 16.3 (mean is 15.1) </Td> </Tr> <Tr> <Th> Absolute magnitude (H) </Th> <Td> − 0.7 </Td> </Tr> <Tr> <Th> Angular diameter </Th> <Td> 0.06" to 0.11" </Td> </Tr> <Tr> <Th_colspan="2"> Atmosphere </Th> </Tr>

Who discovered that pluto was a dwarf planet