Earth Sciences 1086F/G Lecture Notes - Lecture 2: Orion Nebula, Parallax, Local Group
13 Jan 2020
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Light years: the distance that light travels in one year, 9. 4608 x 1012 km. Proxima centauri (closest star that isn"t the sun) 6 months (6 astronomical units, or 300 million km), we can calculate the distance to the star. Should be noted that a star"s brightness dims with distance, so the brightness you see from earth (apparent brightness) is not true: to get the distance, use the following equation: Find a cepheid and measure the time between one brightness peak and the next, which gives us the intrinsic brightness value. Cepheid star inside: this turned out to be a galaxy, and is our closest galaxy, resembling a frisbee. The scale of space: this is a map of the universe as best we can see it. In our immediate environment is a group of about 40- 50 galaxies called the local group: there are 3 really big galaxies in the local.
