Quarks to Cosmos Lecture Sheet 9
Studied by 0 people
Call Kai
Learn
Practice Test
Spaced Repetition
Match
Flashcards
Knowt Play1/12
Earn XP
Description and Tags
Stars & the Sun
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai |
|---|
No analytics yet
Send a link to your students to track their progress
13 Terms
What are the stellar spectral classes and what does the order mean?
O, B, A, F, G, K, M. Ordered by decreasing temperature. Originally alphabetical by spectral line strength.
What is the Sun’s spectral class?
G2V.
Where are red giants, main sequence, and white dwarfs on the HR diagram?
Red giants = upper right; Main sequence = diagonal; White dwarfs = lower left.
What determines if a star is on the main sequence?
Hydrogen fusion in the core.
How does luminosity depend on mass?
L ∝ M^3–4.
How does lifetime depend on mass?
Lifetime ∝ 1 / M^2.5.
What are the regions of the Sun?
Core, Radiative zone, Convective zone, Photosphere, Chromosphere, Corona.
What is hydrostatic equilibrium?
Gravity inward balanced by pressure outward.
What powers the Sun?
Proton-proton chain: H → He + energy. E = mc².
Other products of the pp-chain?
Neutrinos.
How many solar neutrinos reach Earth?~10^38 per second.
Mass lost by Sun per second?~4 × 10^9 kg/s.
Age of the Sun?~4.6 billion years.
Note 
Flashcards (36)