<p>&quot;Satellite type&quot; and &quot;Planet type&quot;.</p>
<p>The terms seem to have been coined by Rudolf Dvorak in 1982 paper &quot;<a href="https://ui.adsabs.harvard.edu/abs/1982OAWMN.191..423D/abstract" rel="noreferrer">Planetenbahnen in Doppelsternsystemen</a>&quot;</p>
<blockquote>
<p>Due to the fact that quasiperiodic orbits exist around stable orbits 3 different types of possible planetary orbits are found: S-types (satellite type orbit around one primary), P-types (orbits around both primaries), and L-types (librating orbits in the vicinity of L4 or L5).</p>
</blockquote>
<p>It's not immediatly clear from this whether &quot;P-type&quot; means &quot;planetary type&quot; or &quot;primary type&quot; (and the full paper would be in German and doesn't seem have been digitised).  However in an English paper from 1986 <a href="http://articles.adsabs.harvard.edu/pdf/1986A%26A...167..379D" rel="noreferrer">Critical orbits in the elliptic restricted three-body problem.</a>  Dvorak is explict:</p>
<blockquote>
<p>There are three types of stable motion for a third massless body that are interesting as regards this problem: the P-type (planet type) surrounding both primary bodies, the S type (satellite type) orbiting one of the primaries and L-type (Librator type) librating around the Langrangian equilibrium points ...</p>
</blockquote>

CC BY-SA 4.0
2020-09-06T06:09:34.250Z
2020-09-06T06:34:21.583Z
2020-09-06T06:34:21.583Z
James K
<p>As explained in various sources (such as <a href="https://astronomy.stackexchange.com/a/14997/25184">that answer</a>), a planet in an s-type orbit orbits one of the stars of a binary star system, whereas a planet in a p-type orbit orbits both stars. A synonym for a p-type orbit (at least in binary star systems, not sure about N-ary systems in general) is &quot;circumbinary&quot;, which is a self-explanatory term.</p>
<p><strong>However, what do &quot;s-type&quot; and &quot;p-type&quot; mean, respectively?</strong></p>
<p>Are &quot;S&quot; and &quot;P&quot; acronyms of anything?</p>

CC BY-SA 4.0
2020-09-05T22:14:02.400Z
p= planetary type s= satellite type https://commons.wikimedia.org/wiki/File:Planets_in_binary_star_systems_-_P-_and_S-type.svg
ACR
CC BY-SA 4.0
2020-09-05T22:19:41.347Z
That seems to answer the question.  Please copy it to the answer box.
James K
CC BY-SA 4.0
2020-09-05T23:06:16.757Z
@JamesK: While it does, and I would eventually accept it if no more comprehensive answer turns up, some background information and references on this terminology are appreciated ... as I find it slightly confusing. So planets can be on planetary or non-planetary orbits, and satellites (which, I think, planets that orbit something are a type of) can be on satellite and non-satellite orbits? Curious.
O. R. Mapper
CC BY-SA 4.0
2021-09-23T02:03:00.717Z
Answers were previously stated in posts above, but if you’re looking for an easy way to remember the difference, the s-types orbit a Single star in the binary while a p-type orbits the Pair.
Lauren
<exoplanet><binary-star><terminology>
What do the words "p-type" and "s-type" mean?
O. R. Mapper
# What do the words "p-type" and "s-type" mean?

(Asked by: username_0 on 2020-09-05)

As explained in various sources (such as [that answer](https://astronomy.stackexchange.com/a/14997/25184)), a planet in an s-type orbit orbits one of the stars of a binary star system, whereas a planet in a p-type orbit orbits both stars. A synonym for a p-type orbit (at least in binary star systems, not sure about N-ary systems in general) is "circumbinary", which is a self-explanatory term.

**However, what do "s-type" and "p-type" mean, respectively?**

Are "S" and "P" acronyms of anything?

**Tags:** exoplanet, binary-star, terminology
> **Comments:**
> **username_1**: p= planetary type s= satellite type https://commons.wikimedia.org/wiki/File:Planets_in_binary_star_systems_-_P-_and_S-type.svg  
> **username_2**: That seems to answer the question.  Please copy it to the answer box.  
> **username_0**: @JamesK: While it does, and I would eventually accept it if no more comprehensive answer turns up, some background information and references on this terminology are appreciated ... as I find it slightly confusing. So planets can be on planetary or non-planetary orbits, and satellites (which, I think, planets that orbit something are a type of) can be on satellite and non-satellite orbits? Curious.  
> **username_3**: Answers were previously stated in posts above, but if you’re looking for an easy way to remember the difference, the s-types orbit a Single star in the binary while a p-type orbits the Pair.  

---

## 1 answers

### Answer by username_2 on 2020-09-06. Score: 12 | Accepted answer

"Satellite type" and "Planet type".

The terms seem to have been coined by Rudolf Dvorak in 1982 paper "[Planetenbahnen in Doppelsternsystemen](https://ui.adsabs.harvard.edu/abs/1982OAWMN.191..423D/abstract)"

> Due to the fact that quasiperiodic orbits exist around stable orbits 3 different types of possible planetary orbits are found: S-types (satellite type orbit around one primary), P-types (orbits around both primaries), and L-types (librating orbits in the vicinity of L4 or L5).

It's not immediatly clear from this whether "P-type" means "planetary type" or "primary type" (and the full paper would be in German and doesn't seem have been digitised). However in an English paper from 1986 [Critical orbits in the elliptic restricted three-body problem.](http://articles.adsabs.harvard.edu/pdf/1986A%26A...167..379D) Dvorak is explict:

> There are three types of stable motion for a third massless body that are interesting as regards this problem: the P-type (planet type) surrounding both primary bodies, the S type (satellite type) orbiting one of the primaries and L-type (Librator type) librating around the Langrangian equilibrium points ...


---

