Eta

Its story

η Leonis traces part of the Sickle, the backwards question mark that outlines the Lion's mane. Modest in appearance from 1,270 light-years away, it is in fact a white supergiant nearly 20,000 times more luminous than the Sun and a future supernova candidate. Since 1943 it has served as the spectral standard for class A0 Ib —a quiet anchor in the cartography of stars.