AS101 Lecture Notes - Lecture 7: Celestial Sphere, Parsec, Orbiting Body
Document Summary
In astronomy the field of view is usually expressed as an angular area viewed by the instrument, in the units of square degrees, or for higher magnification instruments, in square arc-minutes. Earths rotate from w to e, it carries us eastward crossing from the sunset line into the darkness. The average distance to the moon is about 380000km. Distance from sun to dearth d= 150000000km defined as the astronomical unit. au. At a distance of 11000 au it is difficult to grasp the isolation of the stars out of the solar system. 1ly = 6324 au for example if something is a distance d= 4. 366 ly which =276105. 45au which is more than 11000 au so it grasps the isolation of the stars. Astronomical units is not constant in time. It increases at a rate of 15 +- 4cm/cy. The centauri is the brightest star in the southern constellations of centaurs.
