ASTR 207 Lecture Notes - Lecture 1: Black-Body Radiation, Net Force, Light Curve

• School: University of Calgary
• Department: Astronomy
• Course: ASTR 207
• Professor: Rachid Ouyed

Document Summary

What is astronomy? (cid:862)ast(cid:396)o(cid:374)(cid:863) = star (cid:862)(cid:374)o(cid:373)os(cid:863) = law. We deal with objects that we do not how big they are and we do not know how far they are. All we can measure is their angular scale(spread) in the sky. This means that one deals with angles in the sky. In astronomy ones measures the sky using angles. You can use your hand to figure these angles out. (thumb, fist, outstretched hand) Angular measurements: full circle= 360 degrees, 1 degree (cid:1010)(cid:1004)" (cid:894)a(cid:396)(cid:272)(cid:373)i(cid:374)utes(cid:895, (cid:1005)"- (cid:1010)(cid:1004)(cid:863)(cid:894)a(cid:396)(cid:272)se(cid:272)o(cid:374)ds(cid:895) ***by measuring angle of the size, you do not know how far away it is, you have to use trigonometry to figure that out. *** the (cid:373)oo(cid:374) has a(cid:374) (cid:862)a(cid:374)gula(cid:396) size o(cid:396) a(cid:374)gula(cid:396) dia(cid:373)ete(cid:396)(cid:895) of o(cid:374)e half a degree. ***1 degree has one arcminute, and one arcminute has one arcsecond so one degree has 3600 arceseconds. The hypotenuse is always the longest side of a right triangle and is always opposite the right angle. leg.