Properties of the Sun Lab Write-Up

Problem: Use images of the Sun to find the rotation period of the Sun, and to find the velocity of matter leaving the Sun through a coronal mass ejection.

Hypothesis: It was my guess that we could determine the velocity of a coronal mass ejection because we had a way to determine distance and had photos that were representational of time but I figured our method would not give us the most accurate measurement as there is a fair amount of room for error.

Procedure #1: The following are the steps used for our first procedure: 1) we determined the diameter in pixels using the image of the sun. 2) We looked up the actual diameter and divided the actual diameter in km by the measured diameter in pixels and determined a km/pixel image scale. 3) We measured the distance in pixels that the coronal mass ejection moved and multiplied that number by our scale factor to determine the distance the mass ejection moved. 4) We used our calculations to determine the period of the sun in days.

Procedure #2: The following are the steps used for our second procedure: 1) we determined a new image scale by measuring the diameter of the sun in pixels and dividing the actual diameter of the sun in km by the pixel diameter. 2) We pinpointed both of the minimum heights in pixels of the mass ejections, used the distance formula to determine the pixel distance moved and then converted that number to km using our scale factor. 3) We pinpointed both of the maximum heights in pixels of the mass ejections, used the distance formula to determine the pixel distance moved and then converted that number to km using our scale factor. 4) We used our calculated distances to determine the change in height in km. 5) We used the times recorded below each picture to determine the time change. 6) We divided our calculated distance covered by the time it took for the mass ejection to move that distance and found the velocity of the material in km/h. 7) We converted our velocity to mi/hr.

Data & Calculations: Can be seen on the hardcopy of the lab which will be turned in on the day of the test.

Conclusion: We were able to determine the velocity of the coronal mass ejection using simple pictures, pixel measurements and formulas which was interesting.  We determined that the material left the sun at an extremely fast velocity when compared to the velocity of things we are familiar with like cars and airplanes which is kind of mindboggling to think about. As with all labs there was some error in our calculations. This error came from unsteady hands used to determine pixel location as well as small photos that do not allow for very precise measurements.