  Guy Boistel questions the Sun / variable stars analogy at the heart of the
work of Dutch astronomer Albert Brester. The problem of interdisciplinarity
appears in the objectification of the Sun at the end of the 19th century: it is
by mixing astronomy, physics and chemistry that Brester tried to apply
knowledge of the solar atmosphere to the understanding of variable stars, a
fairly confidential field of study still at that time.
