AST101H1 Lecture Notes - Lecture 9: So Hot, Plutonium, Caffeine

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Bryan Gaensler

Document Summary

Basic properties of the sun: diameter: 1 392 000 km (109 times the diameter of earth, mass: 1. 989x1030kg. Solar system by mass: sun = 99. 86% Jupiter= 0. 095: saturn= 0. 029, the rest= 0. 016% The bits we can"t ee: the core: thermonuclear energy core, out to 25% of the radius, 50% of the mass, temperature: 15 million c, nuclear reactions. The bits we can"t ee: radiative zone: from 25%-70% of the radius, 49% of the u(cid:374)"s mass, temp. : few million c: light & heat travel outward from core. The bits we can"t ee: convective zone: from 70% - 100% of the radius, 1% of the su(cid:374)"s mass, temp: less than 1 million c, lots of churning: hot gas rising, cool gas falling. The photosphere: the (cid:862)su(cid:396)fa(cid:272)e(cid:863) of the u(cid:374, not precisely, but it"s where the sun changes from transparent to opaque, average temp: 5500 c, approx. 100 km thick (0. 015% of total radius: photosphe(cid:396)e is (cid:862)g(cid:396)a(cid:374)ulated(cid:863, granules approx.