Wikipedia
Naonobu (crater)
Naonobu is a small lunar impact crater named after Japanese mathematician Ajima Naonobu. It is located on the eastern Mare Fecunditatis, to the northwest of the prominent crater Langrenus, and it forms a triple-crater formation with the adjacent Atwood to the south and Bilharz just to the southwest. Naonobu and Atwood are separated by only a few kilometres.
The interior of this crater has been flooded with basaltic lava, leaving a relatively flat interior and a reduced outer rim. There is no central peak, but a small crater lies just to the southwest of the midpoint. A similar crater lies across the western interior of the rim.
This crater was previously designated Langrenus B before being renamed by the IAU.