1. Astronomy 101 Planetarium Lab Instructor: Brian Pohl ConOps: Craig Zdanowicz Gabrielle Scronte Please do not sit in the front row or the southwest section

2. 2 Syllabus Schedule – Every other week –We WILL meet the weeks of Fall break and Thanksgiving break! Attendance –5 P Labs / 5 Night Labs / 1 Makeup Lab Honor Code Grades –Must hand in 10 labs to receive full credit –You Night Lab TA collects PLabs and grades them Lab Reports –Note: the PLab format is DIFFERENT than Night Lab Due Dates –Due Wednesday the week after lab

3. 3 Office Hours Monday and Tuesdays of non planetarium lab weeks. 3 pm – 5 pm in Morehead room 403 –East entrance facing the arboretum. –Take the elevator on the right to the fourth floor.

4. 4 Why do we study Astronomy?

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7. 7 Place Origin in of Universe

8. 8 General Purpose of Planetarium Lab We want you to “delight” in Astronomy We want you to “Look Up” The Planetarium is a space-time machine –Simulate measurements we could not make in a short space of time, or from Chapel Hill To learn to write precisely about something technical and detailed From a few simple measurements, obtain complex understanding –Foster critical thinking

9. Planetarium Show The delight in looking up part!

10. 10 How do Astronomers make measurements?

11. What affects our ability to observe the stars ?

12. 12 Light Pollution

13. 13 USA 1995

14. 14 Be a MEMBER: International Dark-Sky Association www.darksky.org

15. What can astronomers do to respond to light pollution?

16. 16 Location HAWAII (14,300 ft) CHILE (8,800 ft)

17. 17 Space! The current frontier HUBBLE Space Telescope

18. 18 Other wavelengths of light CRAB NEBULA in Radio and X-RAY

19. 19 Star Counts Lab We will observe the sky with and without light pollution, and measure the difference in the amount of stars we can count Cannot count the whole sky, so we count a part of it, and average the rest! Place eye at large end of cup, point at a region of sky, and count the stars We’ll do this five times … each time select a different portion of the sky

20. Do Star Counts Lab

21. 21 Calculations and Lab Report Calculate the TOTAL number of stars in sky –Dimensions of Cup: L=9cm, D=2cm (write this down) –Total area of sky: A1=2πL 2 –Area observed (once) in cup: A2= (1/4)πD 2 –TOTAL # Stars = (count) x A1/(5xA2) Calculate the ratio of stars with and without light pollution Show all work and equations on a separate page Study the syllabus for correct report format Calculate percent error against the total amount of stars in the sky without light pollution (~3000) Final result: how the sky varies with and without light pollution (the ratio)

22. 22 A Few Brief Words About: Error Analysis Error is not a mistake –It is not “human error” –It merely exists Error is a factor that affect the quality and character of the measured data –Is this a good number? –Is this the ‘right’ number? Some questions to ask yourself: –What am I measuring or observing? [OBJECT] –How am I measuring? [TECHNIQUE] –With what am I observing? [DEVICE] (note: this CAN be you and that is fine) Types of error: –Random error: effects that are not consistent from one measurement to another –Systematic error: effects that are generally the same every time you make an observation How to address error in your lab report: –Where possible be quantitative (but you may not be able to be) –See where error most affects your final result and by how much –How could you correct for this error, now that you know about it? Most importantly: –Do not be vague, be specific about the origin of a source of error –Do not invent an error, support you choice of error with evidence or argument –Do not stress out, you learn with practice how to better examine error over the course of the semester

23. 23 Hand Calibration For next time In order to measure angles in the Planetarium you will: –measure the lengths of your arm, hand and fingers –Refer to pg. 171 for the instructions –Refer to pg. 175 for a diagram

24. All Power Points are on my website: http://www.physics.unc.edu/~bpohl Visit office hours or email me if you have questions! bpohl@physics.unc.edu bpohl@physics.unc.edu Morehead room 403 Mondays, Tuesdays (week-after-lab) 3 - 5pm