Student Project 2 - How Many Stars and Galaxies
Download FTS images for this lesson here.
Here are four images taken around various portions of the Autumn sky.

All exposures are 15 seconds taken between 4AM and 5AM.from Pine Mountain Observatory, with the Piggy Camera, one degree FOV , if you want to reference a sky chart to see where the camera was pointing, by the directions given above.

Inquiry Claim example: Objects are distributed evenly across the sky.

Activity
Count up the stars and the galaxies you observe in each of the four areas of the sky. Stars appear as point-like objects, and galaxies generally appear as smudges. You’ll have to decide on your criteria for what is a star and what is a galaxy, as the fainter stars may appear like galaxies, and some of the distant galaxies may appear like stars. Be consistent with your decision process. You may want to divide up each image into sectors and do the counting with a team, just be sure that everyone agrees on the standards for what is a star and what is a galaxy.

Can you calculate approximately how many stars are in our Galaxy?
How many Galaxies in the visible Universe? How many Stars in the visible Universe (Galaxies x Stars/Galaxy)… what does this imply about number of Planets (current guesses are maybe 1 in 10 stars have Solar Systems, and each system may contain 10 planets!... what does this imply for finding life?)
What major uncertainties are involved and what assumptions are you making when you do the above calculations?
What do you notice about the distribution of the objects?
Why might you see more of one type or another in various parts of the sky?
Think about the concept of a Galaxy, a city of stars.
Could you prove, using your data, that we live within a Galaxy?
What might the “large scale structure” of the Universe look like (how are Galaxies distributed, and why?)

Image IMAGA155 pointed locally SW at Declination 0. 9-23-00
Image IMAGB155 pointed locally W at Declination 40. 9-23-00
Image IMAGC155 pointed locally E at Declination 80. 9-23-00
Image IMAGD155 pointed locally SE at Declination 0. 9-23-00