VARIABLE STARS IN THE EDUCATIONAL CONTEXT: A PROPOSAL INVOLVING THE OBSERVATION OF CLASSICAL CEPHEIDSIN THEHIGH SCHOOL

Abstract

A pedagogical proposal is presented for teaching astronomy through the observation of variable stars, whose brightness change with the passage of time. In particular, this work addresses the monitoring of classical Cepheids, which exhibit regular changes in the intensity of the emitted light due to periodic pulsations, with their radius increasing and decreasing in a cyclic way. The relationship between the period of oscillation and the luminosity of a classical Cepheid is discussed, showing how this property allows for determining how distant the star is. The historical and current importance of the observation of classical Cepheids to estimate distances in the Universe is emphasized, with implications for the formulation of cosmological models. An educational sequence related to the theme is described, structured in three pedagogical moments, encompassing an initial problematization, the organization of knowledge and the systematization of knowledge. This proposal is exemplified considering the case of ℓ Carinae, a classical Cepheid bright enough to be investigated with the naked eye. This paper also seeks to reveal the possible contribution of observational activities to provide contact with concepts and techniques of astronomy and a better understanding of how science develops.