Galileo, in 1612, demonstrated that the Sun rotates on its axis with a rotation period of approximately one month. Our star turns in a west-to-east direction, like the orbital motions of the planets. The Sun, however, is a gas and does not have to rotate rigidly, the way a solid body like Earth does. Modern observations show that the Sun’s rotation speed varies according to latitude; that is, it’s different as you go north or south of the Sun’s equator. Between 1826 and 1850, Heinrich Schwabe, a German pharmacist and amateur astronomer kept daily records of the number of sunspots. What he was looking for was a planet inside the orbit of Mercury, which he hoped to find by observing its dark silhouette as it passed between the Sun and Earth. Unfortunately, he failed to find the hoped-for planet, but his diligence paid off with an even more important discovery: the sunspot cycle. He found that the number of sunspots varied systematically, in cycles about a decade long. In this laboratory, you will engage in tracking the Sun like Galileo and Schwabe during a six-day cycle and then do a simple calculation of the rotational period of our sun.---------------------------------------Distant Nature: Astronomy Exercises 2016 by Stephen Tuttle under license "Creative Commons Attribution Non-Commercial Share Alike".
- Subject:
- Astronomy
- Material Type:
- Activity/Lab
- Author:
- Hollyanna White
- Date Added:
- 01/28/2022