Learn observational astronomy through the methods that power modern discovery Studying distant celestial objects requires mastery of specific observational techniques, yet few introductory textbooks center these methods. Written by John B. Lester, a distinguished professor of astronomy and astrophysics at the University of Toronto, Introduction to Astronomical Optical Observations places observational methods at the core of undergraduate astronomy education, teaching students to measure, analyze, and interpret light from the cosmos. Coverage spans the measurement of angles, distances, and motions in the sky, the operation of telescopes and detectors, and the principles of photometry, imaging, and spectroscopy. The text integrates error analysis and scientific method throughout, while tracing the evolution of astronomical techniques from ancient instruments to modern space observatories. STEM measurement skills taught here transfer directly to related scientific disciplines. Readers will also find: Historical context connecting ancient observational tools to contemporary space observatory technologies, grounding each technique in its scientific developmentRigorous treatment of error analysis and scientific method applicable across all STEM fields beyond astronomy aloneDetailed coverage of photometry, imaging, and spectroscopy principles used to determine stellar composition, temperature, and distancePractical instruction on telescope operation and detector technologies central to modern astronomical data collection and analysisA structure designed for university and college courses while remaining accessible to advanced high school students and citizen astronomers Designed for undergraduate astronomy and astrophysics courses, this textbook also serves advanced high school students and citizen astronomers seeking structured instruction in observational methods. By centering scientific measurement techniques and their historical development, it builds transferable STEM skills that extend well beyond the observatory.