Final answer:
Sunspots are tracked as the Sun rotates, with a rotation period of about 25 days at the equator, increasing with latitude due to differential rotation. Galileo's observations in 1612 provided initial insights into this process, which has been continually studied to understand solar dynamics and magnetic activity cycles.
Step-by-step explanation:
As the sun rotates, an individual sunspot can indeed be tracked across its face from east to west. The process of tracking these sunspots provides us with valuable information about the Sun's rotational patterns. Galileo, in 1612, utilized the tracking of sunspots to show that the Sun rotates on its axis, taking about 25 days at the equator and varying to about 36 days at latitude 80°. This phenomenon is referred to as differential rotation because the sun does not rotate as a solid body but as a gaseous one, with rotation rates differing at various latitudes.
Sunspots themselves are cooler, dark regions on the Sun's surface, with temperatures about 2000 K lower than their surroundings. They can range greatly in size, with some becoming much larger than Earth, and they generally have two parts — an umbra and a penumbra. The complexity and movement of sunspots are comparative to that of storms on Earth, drifting slowly in relation to the Sun's rotation. Additionally, the sunspot cycle, averaging 11 years, reflects the number of visible sunspots, correlating with the Sun's magnetic activity.
The rotation of the Sun and the movement of sunspots are important areas of study in solar physics and substantially contribute to our understanding of solar dynamics and the impact of solar activity on space weather. Observations such as those made by SOHO/NASA/ESA on March 30, 2001, tracking large sunspot groups, help astronomers determine various properties of the Sun's surface and magnetic field behaviors.