<p>This is <a href="http://en.wikipedia.org/wiki/Pi_(letter)#Variant_pi" rel="nofollow noreferrer">a variant of pi</a>, or &quot;pomega&quot;.</p>
<p>In LaTeX, you can get it by using</p>
<pre><code>                                          \varpi
</code></pre>
<p><span class="math-container">$$\varpi$$</span></p>
<p><a href="https://tex.stackexchange.com/questions/216358/using-mathematical-symbols-alpha-beta-implies-in-latex/216362#216362">TeX</a> has a question on the 'var' prefix, and <a href="http://en.wikibooks.org/wiki/LaTeX/Mathematics#List_of_Mathematical_Symbols" rel="nofollow noreferrer">Wikibooks</a> has something relevant.</p>
<blockquote>
<p>The various forms of pi are present in Unicode as:</p>
<ul>
<li>U+03A0 Π greek capital letter pi (HTML Π · Π)</li>
<li>U+03C0 π greek small letter pi (HTML π · π)</li>
<li>U+03D6 ϖ greek pi symbol (HTML ϖ · ϖ)</li>
<li>U+220F ∏ n-ary product (HTML ∏ · ∏)</li>
<li>U+1D28 ᴨ greek letter small capital pi (HTML ᴨ)</li>
<li>U+1D70B  mathematical italic small pi (HTML )</li>
<li>U+1D6D1  mathematical bold small pi (HTML ).</li>
</ul>
</blockquote>
<p>It is used to denote the <a href="http://en.wikipedia.org/wiki/Longitude_of_the_periapsis" rel="nofollow noreferrer">longitude of the periapsis</a>, as in your case.</p>

CC BY-SA 3.0
2015-06-20T19:04:30.693Z
2015-06-20T19:09:55.733Z
2020-06-17T09:47:40.653Z
HDE 226868
<p>I've been working on a programming project involving Peter Duffett-Smith's <em>Practical Astronomy With Your Calculator (3rd Ed.)</em>, which has a large number of mathematical/astronomical formulas in it. There's a part at the end of the book for symbols and abbreviations, which contains this:</p>
<p><img src="https://i.sstatic.net/QWUdk.jpg" alt="enter image description here" /></p>
<p>After doing some Google-fu, I was unable to find the name of the symbol. Would anyone smarter than me (which should be quite a few of you... heck, quite a <em>lot</em>) know what this is? Hopefully there's Unicode for it...</p>

CC BY-SA 3.0
2015-06-23T19:51:04.503Z
Detexify (http://detexify.kirelabs.org/classify.html) was able to identify it for me pretty quickly.  Might come in handy in the future.
BowlOfRed
<the-sun><fundamental-astronomy><notation>
Name and language of symbol in astronomy book
nerdenator
# Name and language of symbol in astronomy book

(Asked by: username_0 on 2015-06-20)

I've been working on a programming project involving Peter Duffett-Smith's *Practical Astronomy With Your Calculator (3rd Ed.)*, which has a large number of mathematical/astronomical formulas in it. There's a part at the end of the book for symbols and abbreviations, which contains this:

![enter image description here](https://i.sstatic.net/QWUdk.jpg)

After doing some Google-fu, I was unable to find the name of the symbol. Would anyone smarter than me (which should be quite a few of you... heck, quite a *lot*) know what this is? Hopefully there's Unicode for it...

**Tags:** the-sun, fundamental-astronomy, notation
> **Comments:**
> **username_1**: Detexify (http://detexify.kirelabs.org/classify.html) was able to identify it for me pretty quickly.  Might come in handy in the future.  

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## 1 answers

### Answer by username_2 on 2015-06-20. Score: 2 | Accepted answer

This is a variant of pi, or "pomega".
In LaTeX, you can get it by using
                                          \varpi

$$\varpi$$
TeX has a question on the 'var' prefix, and Wikibooks has something relevant.

The various forms of pi are present in Unicode as:

U+03A0 Π greek capital letter pi (HTML Π · Π)
U+03C0 π greek small letter pi (HTML π · π)
U+03D6 ϖ greek pi symbol (HTML ϖ · ϖ)
U+220F ∏ n-ary product (HTML ∏ · ∏)
U+1D28 ᴨ greek letter small capital pi (HTML ᴨ)
U+1D70B  mathematical italic small pi (HTML )
U+1D6D1  mathematical bold small pi (HTML ).


It is used to denote the longitude of the periapsis, as in your case.


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