PASJ publishes research papers on all aspects of astronomy, astrophysics, and fields closely related to them. From its foundation in 1949 till 1985, PASJ was published quarterly. From 1986, PASJ has been published bimonthly. In addition to normal papers, we accept 'Letters to the Editor', which aim at quick communication of observational as well as theoretical results having strong impact on astronomy. The Letters should be within four printed pages.