What does observing a blueshift in a star's spectrum definitively indicate about its motion relative to Earth?
Answer
The star is approaching our solar system.
A blueshift is the definitive indicator that a star is approaching the observer on Earth. When a star moves toward us, the light waves it emits are effectively 'squashed' together, causing their wavelength to shorten. This shortening shifts the observed spectral features towards the shorter, higher-energy end of the spectrum, known as the blue end. This measurement allows astronomers to calculate the star's radial velocity component directed toward the observer, confirming that the distance between the star and Earth is decreasing.
#Videos
Light and Motion: the Doppler Effect - YouTube
Related Questions
What physical effect determines if a star is racing toward or receding from Earth?What does observing a blueshift in a star's spectrum definitively indicate about its motion relative to Earth?What physical feature forms the unique spectral fingerprint analyzed by astronomers?What component of a star's motion is measured by the Doppler shift, known as radial velocity?If a star is moving away from Earth, what happens to the light waves it emits?What is the local gravitational significance of detecting a blueshift from the Andromeda Galaxy?How is the fractional change in wavelength ($ rac{\Delta\lambda}{\lambda_0}$) mathematically related to the star's radial velocity ($v$)?What is the primary observational evidence cited regarding the vast majority of distant galaxies?What is required to precisely measure the incredibly small wavelength shifts for nearby stars?How does the 'wobble' of a star due to an orbiting planet cause detectable spectral changes?