<p><a href="https://galex.stsci.edu/GR6/?page=faq#ANSWER2" rel="nofollow noreferrer">GALEX magnitudes</a> use the <a href="https://en.wikipedia.org/wiki/AB_magnitude" rel="nofollow noreferrer">AB system</a>, which means that <span class="math-container">$F_{0} \approx 3631$</span> janskys for both NUV and FUV, <em>by definition</em>.</p>

CC BY-SA 4.0
2019-07-15T09:02:54.880Z
2019-07-15T09:02:54.880Z
Peter Erwin
<p>I'm trying to compile a table showing the wavelengths and flux at m=0 for WISE, Spitzer and GALEX, but I can't find the right data for GALEX. Here's what I have so far:</p>

<pre><code>        Band    Wavelength      F_0
                micrometers    Jansky
        ------------------------------
        FUV     0.152   
        NUV     0.227   
        U       0.365           1810
        B       0.445           4260
        V       0.551           3640
        R       0.658           3080
        I       0.806           2550
        J       1.220           1600
        H       1.630           1080
        K       2.190           670
        W1      3.4             309.54
        W2      4.6             171.787
        SPIT8   8               64.13
        W3      12              37.674
        W4      22              8.363
</code></pre>

<p>I got most of the info from <a href="https://www.cfa.harvard.edu/~dfabricant/huchra/ay145/mags.html" rel="nofollow noreferrer">here</a>. The information I found for GALEX on page 687 of <a href="https://pdfs.semanticscholar.org/5321/ac845601d0882b5e7d32f6dfdd4d60acb1f0.pdf" rel="nofollow noreferrer">this paper</a> gives m_0 for NUV and FUV, but no F_0. How can I change m_0 to F_0?</p>

<telescope><space-telescope><magnitude><wavelength>
Comparing info for WISE and GALEX
Jim421616
# Comparing info for WISE and GALEX

(Asked by: username_0 on 2019-07-11)

I'm trying to compile a table showing the wavelengths and flux at m=0 for WISE, Spitzer and GALEX, but I can't find the right data for GALEX. Here's what I have so far:
        Band    Wavelength      F_0
                micrometers    Jansky
        ------------------------------
        FUV     0.152   
        NUV     0.227   
        U       0.365           1810
        B       0.445           4260
        V       0.551           3640
        R       0.658           3080
        I       0.806           2550
        J       1.220           1600
        H       1.630           1080
        K       2.190           670
        W1      3.4             309.54
        W2      4.6             171.787
        SPIT8   8               64.13
        W3      12              37.674
        W4      22              8.363

I got most of the info from here. The information I found for GALEX on page 687 of this paper gives m_0 for NUV and FUV, but no F_0. How can I change m_0 to F_0?

**Tags:** telescope, space-telescope, magnitude, wavelength


---

## 1 answers

### Answer by username_1 on 2019-07-15. Score: 0 | Accepted answer

[GALEX magnitudes](https://galex.stsci.edu/GR6/?page=faq#ANSWER2) use the [AB system](https://en.wikipedia.org/wiki/AB_magnitude), which means that $F\_{0} \approx 3631$ janskys for both NUV and FUV, *by definition*.


---

