Final answer:
The dark ovals Gabriel drew on his model of the Sun most likely represent sunspots, which are cooler, darker regions caused by increased magnetic activity.
Step-by-step explanation:
The ovals Gabriel drew on his basketball to represent the Sun's surface features most likely depict sunspots. Sunspots are significant and easily identifiable features on the Sun's surface, characterized by their darker appearance in contrast to the surrounding areas.
These spots are darker because they are cooler than the other regions of the Sun, typically at a temperature of about 3800 K, while the surroundings are at about 5800 K. Sunspots are caused by increased magnetic activity and can be large enough to be seen with the eye under certain conditions, such as through haze or mist that diminishes the Sun's brightness.
However, caution is always advised when observing the Sun to avoid eye damage.
Due to their distinct visibility, sunspots have been observed for over a thousand years, and tracking their movement across the Sun's surface can demonstrate the star's rotation on its axis.
Before the invention of the telescope, the presence and movements of sunspots provided some of the first clues that the Sun was not an unchanging, perfect sphere, but rather an active and dynamic star.