Posted by **Sethi** on Friday, April 27, 2007 at 12:44pm.

A line in star's spectrum lies at 400.0 nanometers. In the laboratory, that same line lies at 400.2 nanometers. How fast is the star moving along the line of sight; that is, what is its radial velocity? Is it moving toward or away from us?

Since the wavelength shift is to shorter wavelengths (from 400.2 in the lab to 400.0, the star is moving toward observer (Earth).

The speed of approach along the line of sight, V, is given by

(400.2 - 400.0)/400.0 = 0.2/400 = V/c

Solve for V.

## Answer this Question

## Related Questions

- Physics-Astronomy - A high-velocity star HVS 1 is moving at 600 km/s, 0.2% speed...
- physics - The yellow line emitted by a helium discharge tube in the laboratory ...
- Science - In general, the narrower the spectral line of a star A.the hotter the ...
- chemistry - Atomic hydrogen produces well-known series of spectral lines in ...
- Physics - Two telescopes A and B spot a star. Telescope A reports the position ...
- Astronomy - Another star cluster ("star cluster 2") lies 7.4 Mega-parsecs from ...
- Science - In general, the narrower the spectral line of a star A.the hotter the ...
- Math - Rewrite the following definition as a biconditional: Points that lie on ...
- geometry - Suppose line PQ has endpoints P(2,3) and Q(8,-9). Find the ...
- Astrophysics - Star Power and Temperature Star A and Star B Consider two stars ...

More Related Questions