Continuing professional development for teachers in the physical sciences is
crucial to maintaining high-quality instruction, especially when addressing
modern physics. Nevertheless, the teaching of these topics often relies on
theoretical models that may seem abstract and removed from practical
applications. In this context, research in astrophysics provides many valuable
insights into the nature of light and its fundamental properties, such as
continuous and discrete spectra, blackbody radiation, and atomic orbitals. This
paper, aimed at both high school and university-level physics teachers,
examines the peculiarities of the emission and absorption spectra of various
types of astronomical objects and demonstrates how spectroscopy is applied in
astrophysics research. From this perspective, the study conceptually
illustrates how astrophysicists, by measuring light spectra, determine the
composition, physical properties, origin, and evolution of celestial bodies
and, by extension, of the universe as a whole. By understanding not only the
theory but also the direct applications of astronomical spectroscopy, teachers
will be better prepared to guide their students, thereby showcasing the true
value of modern physics in the real world.