Which demonstration provides the best opportunity for students to understand why the Sun appears larger than other stars despite many stars being larger?

• A. Positioning two lit bulbs of the same size at different distances from an observer
• B. Using a telescope to view distant stars
• C. Measuring star brightness
• D. Observing star colors

Answer: (A)

Apparent size in the sky depends on both how big something actually is and how far away it is. When two objects have the same real size, the one that is closer will look larger because it subtends a bigger angle in your view. The demonstration with two lit bulbs of equal size at different distances shows this directly: the nearer bulb fills more of your field of view, while the farther one appears smaller. This helps explain why the Sun looks larger than distant stars—the Sun is much closer to Earth, so its disk appears bigger even though some stars are physically larger. The other options don’t isolate this distance effect as clearly: a telescope view can change detail but isn’t a direct size-versus-distance comparison; measuring brightness relates to luminosity; and star colors relate to temperature.