Observational Astronomy
Observational astronomy concerns the study of celestial objects and phenomena through direct observation, utilizing various ground- and space-based telescopes and instruments to analyze light, radiation, and other signals across different wavelengths. In the context of cosmology, observational astronomy provides empirical evidence for theories about the structure, evolution, and origins of the universe by examining its most distant reaches, such as galaxy clusters and quasars, and probing phenomena like dark matter and dark energy. Observational techniques encompass spectroscopy, imaging, photometry, polarimetry, and interferometry, among others. This subfield shares close ties with astrophysics, but focuses primarily on data acquisition rather than theory development or computation.