Demonstrations of atmospheric scintillation: Stars vs. planets

When teaching observational techniques in astronomy courses, it is important to expose students to atmospheric effects, including seeing and transparency. Transparency characterizes the clarity of the atmosphere, while seeing relates to the sharpness of astronomical images caused by the stability of Earth’s atmosphere. Both factors can degrade astronomical observations,¹ making techniques like adaptive optics (e.g., Refs. 2–4), mountaintop observatories, and placing telescopes in space a necessity. On a personal level, these atmospheric effects explain a common phenomenon that many have noticed, the twinkling of stars.^5–7 In some cases, the twinkling star demonstrations outlined in the literature either are complicated to set up² or could mislead students about all the processes involved.⁸ Many demonstrations focus solely on either the effects of atmospheric turbulence^9,10 or temperature variations that cause changes in the refractive index of air.¹¹ Here we present easy and straightforward demonstrations...