Parallax Physics

HW #4

Chp 0 # 12, 13, 14

12) The motion of a relatively close object with a more distant background as the location of the observer changes. An example of a parallax would be the needle style speedometer gauge in the dashboard of a motor vehicle. When looking straight ahead, it will show you the exact speed. But when viewed from the passenger seat, due to the angle the needle may appear to be at a different speed.

13) It is necessary because it is very difficult to measure at that angle.

14) The two pieces of information are, distant and angular diameter.

Chp 10 # 1, 2, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15

1) Using the parallax is used to measure the closest stars. The stars are so far away that no adequate way to measure on the Earth. So comparing observations made of a star at different times of the year, they

5) Astronomers will define star brightness in a way of apparent magnitude (looking at it from Earth how bright does it appear) and the absolute magnitude (from a standard distance of 32.6 light years or 10 parsecs on how bright the star appears)

6) The temperature of a star is measured through two or more optical filters, then fitting a black body curve to the results. To help find an accurate temperature and composition would be spectroscopic observation. They are classified by their absorption lines in the spectra. Spectral classes by decreasing temperature are O B A F G H K M

7) The letter represents the amount of hydrogen absorption lines O, B, A, F, G, K, and M. “Oh, Be, A, Fine, Guy, Kiss, Me.”

8) Information to plot a star on the H-R diagram is luminosity versus temperature for a few well known stars. Luminosity (solar units and surface temperature (K) O B A F K M (spectral classification) So for instance the sun has a luminosity of one solar unit. The temperature off the scale is 5800K – a type of