Starlight conclusion Apply Wiens law and Kirchoffs Laws
- Slides: 15
Starlight (conclusion) Apply Wien’s law and Kirchoff’s Laws to deduce Properties of stars
Kirchoff’s First Law + Wien’s Law • Hot, opaque objects produce continuous spectrum • The hotter the object, the bluer it is • Wien’s Law lmax = 2. 9 E-03/T • The hotter an object, the brighter it is Demo
Kirchoff’s First Law + Wien’s Law
Kirchoff’s 2 nd Law: Emission Line Spectra Wavelengths of emission lines unique “fingerprint” of element
Kirchoff’s Third Law: Absorption Spectra See Figure 16. 6
Starlight…application of spectroscopy to stars • Continuous spectrum gives surface temperature (Wien’s Law) • Spectral lines give chemical composition, temperature (also), speed of rotation (How? ) and other properties • Examples of stellar spectra (Figure 16. 11)…what can we say?
Spectral classes of stars: O, B, A, F, G, K, M What can you say about the temperatures of these stars?
Examples of stellar spectra Question: apply Wien’s Law to the O 5 star. What Can you say about its Temperature (relative to the Sun? )
With information provided by spectroscopy, we can search for correlations between stellar properties
What the data show: the Hertzsprung. Russell Diagram Highest quality data from the Hipparchos spacecraft
The Hertzsprung-Russell Diagram and the Types of Stars • • • See Figure 16. 19 Types of stars, important terms Main Sequence Giants Supergiants White dwarfs What does it all mean?
The Hertzsprung-Russell Diagram
Understanding the Main Sequence (stars like the Sun) • A statistical argument (no physics) • Physical argument 1: what holds stars up? • Physical argument 2: what powers the stars (where do they get their energy supply? )
The nature of the Main Sequence #1: the MS as a Cambus Stop Many more people seen on the sidewalk near a Cambus stop than a random point
The Main Sequence is a long-lived phase of stellar evolution. Stars spend a much longer time here than in other parts of the HR diagram
- Kirchoffs current law
- Kirchoffs current law
- Kirchoffs current law
- Kirchoffs loop law
- Derive ohms law
- Stefan boltzmann law
- Seven ages of starlight
- Starlight assistant
- Rf starlight
- Analyzing starlight
- Starlight italia
- Cross apply vs outer apply
- Parallel circuit rules
- Kirchoffs rules
- Kirchhoffs junction rule
- Chapter 2 administrative and traffic laws