Book contents
- Fundamentals of Astrophysics
- Reviews
- Fundamentals of Astrophysics
- Copyright page
- Dedication
- Contents
- Preface to the Second Edition
- Preface to the First Edition
- Part I Stellar Properties
- 1 Introduction
- 2 Astronomical Distances
- 3 Stellar Luminosity
- 4 Surface Temperature from a Star’s Color
- 5 Stellar Radius from Luminosity and Temperature
- 6 Light Intensity and Absorption
- 7 Surface Gravity and Escape/Orbital Speed
- 8 Stellar Ages and Lifetimes
- 9 Stellar Space Velocities
- 10 Using Binary Systems to Determine Masses and Radii
- 11 Stellar Rotation
- 12 Light Intensity and Absorption
- 13 Observational Methods
- 14 Our Sun
- Part II Stellar Structure and Evolution
- Part III Interstellar Medium and Formation of Stars and Planets
- Part IV Our Milky Way and Other Galaxies
- Part V Cosmology
- Book part
- Index
6 - Light Intensity and Absorption
from Part I - Stellar Properties
Published online by Cambridge University Press: 10 November 2025
Book contents
- Fundamentals of Astrophysics
- Reviews
- Fundamentals of Astrophysics
- Copyright page
- Dedication
- Contents
- Preface to the Second Edition
- Preface to the First Edition
- Part I Stellar Properties
- 1 Introduction
- 2 Astronomical Distances
- 3 Stellar Luminosity
- 4 Surface Temperature from a Star’s Color
- 5 Stellar Radius from Luminosity and Temperature
- 6 Light Intensity and Absorption
- 7 Surface Gravity and Escape/Orbital Speed
- 8 Stellar Ages and Lifetimes
- 9 Stellar Space Velocities
- 10 Using Binary Systems to Determine Masses and Radii
- 11 Stellar Rotation
- 12 Light Intensity and Absorption
- 13 Observational Methods
- 14 Our Sun
- Part II Stellar Structure and Evolution
- Part III Interstellar Medium and Formation of Stars and Planets
- Part IV Our Milky Way and Other Galaxies
- Part V Cosmology
- Book part
- Index
Summary
In reality stars are not perfect blackbodies, and so their emitted spectra don’t depend solely on temperature, but instead contain detailed signatures of key physical properties like elemental composition. For atoms in a gas, the ability to absorb, scatter and emit light can likewise depend on the wavelength, sometimes quite sharply. We find that the discrete energies levels associated with atoms of different elements are quite distinct. We introduce the stellar spectral classes (OBAFGKM).
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- Fundamentals of Astrophysics , pp. 35 - 42Publisher: Cambridge University PressPrint publication year: 2025
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