Homework Help: astronomy

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.

No one has answered this question yet.

Answer this Question

Related Questions

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 ...
Astrophysics - Star Power and Temperature Star A and Star B Consider two stars ...
Physics-Astronomy - A high-velocity star HVS 1 is moving at 600 km/s, 0.2% speed...
science - if the spectrum of a star indicates that the star shines with a red ...
Science - In general, the narrower the spectral line of a star A.the hotter the ...
Astronomy - Star 'A' has twice the radius of star 'B'. The ratio...
physics - Express 10 to the negative 7 meters into nanometers. Answer in ...
Science: Astronomy - How many times longer does a 0.50 -M star fuse hydrogen at...

For Further Reading

First Name:
School Subject:
Answer: