ASTR 1210 Lecture Notes - Lecture 5: Planetshine, Universal Time, Heel Stone

• School: University of Virginia
• Department: Astronomy
• Course: ASTR 1210
• Professor: Murphy Edward

Document Summary

Is measured in hours, minutes, and seconds. This is because the earth rotates, we see different parts of the sky throughout the night. If an object at 3h 5m 38s is overhead now, in an hour from now an object will be at 4h. 0 hours right ascension is by convention the right ascension of the sun on the vernal equinox (march 21st: object is thus 3h 5m 38s east of the vernal equinox. Declination is measured in degrees, arcminutes, and arseconds: 60 arcmiuntes in an arcdegree, and 60 arc seconds in an arcminute, the symbols for arcsin and arcsec are the same as for feet and inches. Closest to the sun: winter, spring, fall. Closest to the sun: summer, fall, spring. The variation in earth-sun distance over the course of each year has virtually no effect on the seasons.