Spectroscopy of Stars: Analyzing Absorption Spectra and Their Implications

The video explains the spectrum of stars, focusing on absorption spectra. It covers how electromagnetic radiation from stars interacts with gases in their outer layers, producing absorption lines. The video discusses Wien's law for calculating surface temperature, the chemical composition of stars, and how Doppler's effect reveals translational and rotational velocities. It also explains how density affects absorption lines. Key takeaways include understanding the relationship between spectra and various stellar properties.

What type of spectrum is produced when electromagnetic radiation passes through the outer layers of a star?

• Absorption spectrum

• Gamma-ray spectrum

• Emission spectrum

• Continuous spectrum

What is the relationship between peak wavelength and surface temperature according to Wien's displacement law?

• Directly proportional

• Inversely proportional

• Unrelated

• Exponentially proportional

If a star's peak wavelength is 550 nanometers, what is its approximate surface temperature in kelvins?

• 3000 K

• 5269 K

• 6000 K

• 4500 K

How can the chemical composition of a star be determined from its absorption spectrum?

• By analyzing the star's size

• By comparing with emission spectra of known elements

• By observing the star's color

• By measuring the star's brightness

What phenomenon causes the absorption lines to shift towards the red part of the spectrum when a star is moving away from us?

• Doppler broadening

• Spectral inversion

• Redshift

• Blueshift

What is the effect called when a star's absorption lines shift towards the blue part of the spectrum?

• Spectral broadening

• Doppler effect

• Redshift

• Blueshift

How does a star's rotational velocity affect its absorption lines?

• Broadens them

• Shifts them to the ultraviolet

• Causes them to disappear

• Makes them narrower

What happens to the absorption lines of a star with higher density?

• They shift to the infrared

• They become broader

• They become narrower

• They remain unchanged

What is the relationship between a star's density and the pressure in its outer layers?

• Density and pressure are unrelated

• Higher density leads to higher pressure

• Density affects only the star's temperature

• Higher density leads to lower pressure

What causes the broadening of absorption lines in stars with higher density?

• Reduced electromagnetic radiation

• Increased collision rate between gas molecules

• Lower pressure in the star

• Decreased energy levels of electrons