<ol>
<li><p>Look up the laboratory wavelengths of the Calcium H and K lines</p></li>
<li><p>Calculate the redshift implied by the observed wavelengths of the H and K lines.
$$ v/c = (\lambda - \lambda_0)/\lambda_0,$$
where $v$ is the implied recession velocity, $c$ is the speed of light, $\lambda$ is the observed wavelength and $\lambda_0$ is the laboratory wavelength.</p></li>
<li><p>Plot recession velocity versus distance and see what you get.</p></li>
<li><p>Read about the <a href="http://astro.wku.edu/astr106/Hubble_intro.html" rel="nofollow">Hubble redshift-distance relation</a>.</p></li>
</ol>

CC BY-SA 3.0
2015-03-03T21:17:37.197Z
2015-03-03T21:17:37.197Z
ProfRob
<p>I had a question about the following chart. What mathematical observation or equation could be made about the data given in respect to the doppler effect? I'm confused if this means that planets are moving at an exponential rate away from us? Would these galaxies appear blue shifted? Thank you in advance for any sort of help.</p>

<p><img src="https://i.sstatic.net/dQ2wC.png" alt="Table"></p>

CC BY-SA 4.0
2021-12-06T02:27:09.053Z
What is the source of the table of distance and spectral data above?
I cannot seem to find the text source of the data and have used the information and changed the units from angstroms to nm.
Paul White
<galaxy>
Help w/ Hubble's Law + Doppler Effect.
George Gall
# Help w/ Hubble's Law + Doppler Effect.

(Asked by: username_0 on 2015-03-03)

I had a question about the following chart. What mathematical observation or equation could be made about the data given in respect to the doppler effect? I'm confused if this means that planets are moving at an exponential rate away from us? Would these galaxies appear blue shifted? Thank you in advance for any sort of help.

![Table](https://i.sstatic.net/dQ2wC.png)

**Tags:** galaxy
> **Comments:**
> **username_1**: What is the source of the table of distance and spectral data above? I cannot seem to find the text source of the data and have used the information and changed the units from angstroms to nm.  

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## 1 answers

### Answer by username_2 on 2015-03-03. Score: 1

1. Look up the laboratory wavelengths of the Calcium H and K lines
2. Calculate the redshift implied by the observed wavelengths of the H and K lines.
   $$ v/c = (\lambda - \lambda\_0)/\lambda\_0,$$
   where $v$ is the implied recession velocity, $c$ is the speed of light, $\lambda$ is the observed wavelength and $\lambda\_0$ is the laboratory wavelength.
3. Plot recession velocity versus distance and see what you get.
4. Read about the [Hubble redshift-distance relation](http://astro.wku.edu/astr106/Hubble_intro.html).


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