<blockquote>
  <p>I am beginning to assume that our solar system is not unique and that every star has several planets.</p>
</blockquote>

<p>Not quite, but indeed a <a href="http://www.nature.com/nature/journal/v481/n7380/full/nature10684.html">study published in Nature in 2012</a> found that, based on our observations so far, roughly 17% of stars host Jupiter-mass planets, 52% host "Cool Neptunes" and 62% host Super-Earths. (Note that these percentages do not add up to 100%, because they are not mutually exclusive possibilities). This was particularly surprising, because half of all visible stars are believe to be in <a href="https://en.wikipedia.org/wiki/Binary_star">binary systems</a>, which would make planetary systems very unstable, but some binary systems have been <a href="http://physicsworld.com/cws/article/news/2014/oct/31/planet-forming-stream-found-in-binary-star-system">found to have planets</a> too.</p>

<p>So indeed it seems <em>the majority</em> of stars have planets, but it's very unlikely that all of them do.</p>

<p>However, the exact answer to your question "do we <strong>know</strong> of any stars with no planets" has got to be "no", because there remains a possibility that they have planets that we simply haven't been able to detect, because of <a href="http://blog.thingswedontknow.com/2013/03/detection-and-discovery-of-exoplanets.html">limitations in our techniques</a> to detect them.</p>

CC BY-SA 3.0
2015-07-24T20:08:22.477Z
I think there are some important points here.   In my opinion, it should be surprising if a star doesn't have planets, and you'd generally need to give a mechanism for ***why there aren't***.   For example, instability of orbits due to companion stars, or a past pass by a massive object.     Think about this for comparison:   Based evidence from our solar system, it certainly appears that gas giants have many satellites.   A Jupiter with no moon would be very surprising unless you had a reason why it was moonless.   What is different about stellar formation?
ThePopMachine
CC BY-SA 3.0
2015-07-24T20:40:04.463Z
I just want to add this on Binary systems.   The belief based on observation that most stars were in a binary system was wrong:  http://www.space.com/1995-astronomers-wrong-stars-single.html    Your link mentions that as well, and goes on to talk about planets in binary systems:  https://en.wikipedia.org/wiki/Binary_star#Research_findings
userLTK
CC BY-SA 3.0
2015-09-13T21:24:04.260Z
The percentages quoted are lower limits, because they refer to the percentage of stars that have planets *within a certain (fairly small) orbital separation*. We really don't know of any stars that definitely *don't* have planets.
ProfRob
CC BY-SA 3.0
2015-07-24T11:53:52.857Z
2015-07-24T13:54:05.403Z
Eddy
<p>We have been looking for planets around other stars for a while (see related <a href="https://space.stackexchange.com/questions/1484">https://space.stackexchange.com/questions/1484</a> ) and we are finding lots of planets, some of them are <a href="https://en.wikipedia.org/wiki/Kepler-452b" rel="noreferrer">Earth like</a> According to an the answer at <a href="https://space.stackexchange.com/questions/4062">https://space.stackexchange.com/questions/4062</a> there are over 14,000 stars within 100 light years of Earth, the answer goes on to say there are "1,500 potentially habitable planets within 100 light-years" of Earth</p>

<p>Based on current trends it looks like there are lots of stars with lots of planets.  I am beginning to assume that our solar system is not unique and that  every star has several planets.</p>

<p>Are there any Stars that we know are without any planets?</p>

CC BY-SA 3.0
2015-07-24T11:47:54.337Z
[Wikipedia](https://en.wikipedia.org/wiki/Proxima_Centauri): **Searches for companions orbiting Proxima Centauri have been unsuccessful, ruling out the presence of brown dwarfs and supermassive planets. Precision radial velocity surveys have also ruled out the presence of super-Earths within the star's habitable zone. The detection of smaller objects will require the use of new instruments, such as the James Webb Space Telescope, which is scheduled for deployment in 2018.** If we don't know for certain for the closest star, we ain't know zilch.
Deer Hunter
CC BY-SA 3.0
2015-07-24T12:29:09.593Z
@TildalWave Eddy has a pretty good answer below (+1), He (and Deer Hunter) suggest that multiple star systems are not capable of holding a planet in a stable orbit.  So if you can define the criteria that = no planet with a couple of examples and reasons. that would be good.
James Jenkins
CC BY-SA 3.0
2015-07-24T12:51:48.120Z
@TildalWave - a good point on binaries (with a possible exception of Tattooine - "I saw it on big screen it must be true" :).
Deer Hunter
CC BY-SA 3.0
2015-07-24T14:59:15.567Z
*"I narrowed the question.."*  I deleted an obsolete comment.  :)
Andrew Thompson
<exoplanet>
Are there any Stars we know don't have planets?
James Jenkins
# Are there any Stars we know don't have planets?

(Asked by: username_0 on 2015-07-24)

We have been looking for planets around other stars for a while (see related <https://space.stackexchange.com/questions/1484> ) and we are finding lots of planets, some of them are [Earth like](https://en.wikipedia.org/wiki/Kepler-452b) According to an the answer at <https://space.stackexchange.com/questions/4062> there are over 14,000 stars within 100 light years of Earth, the answer goes on to say there are "1,500 potentially habitable planets within 100 light-years" of Earth

Based on current trends it looks like there are lots of stars with lots of planets. I am beginning to assume that our solar system is not unique and that every star has several planets.

Are there any Stars that we know are without any planets?

**Tags:** exoplanet
> **Comments:**
> **username_1**: [Wikipedia](https://en.wikipedia.org/wiki/Proxima_Centauri): **Searches for companions orbiting Proxima Centauri have been unsuccessful, ruling out the presence of brown dwarfs and supermassive planets. Precision radial velocity surveys have also ruled out the presence of super-Earths within the star's habitable zone. The detection of smaller objects will require the use of new instruments, such as the James Webb Space Telescope, which is scheduled for deployment in 2018.** If we don't know for certain for the closest star, we ain't know zilch.  
> **username_0**: @TildalWave Eddy has a pretty good answer below (+1), He (and Deer Hunter) suggest that multiple star systems are not capable of holding a planet in a stable orbit.  So if you can define the criteria that = no planet with a couple of examples and reasons. that would be good.  
> **username_1**: @TildalWave - a good point on binaries (with a possible exception of Tattooine - "I saw it on big screen it must be true" :).  
> **username_2**: *"I narrowed the question.."*  I deleted an obsolete comment.  :)  

---

## 1 answers

### Answer by username_3 on 2015-07-24. Score: 17 | Accepted answer

> I am beginning to assume that our solar system is not unique and that every star has several planets.

Not quite, but indeed a [study published in Nature in 2012](http://www.nature.com/nature/journal/v481/n7380/full/nature10684.html) found that, based on our observations so far, roughly 17% of stars host Jupiter-mass planets, 52% host "Cool Neptunes" and 62% host Super-Earths. (Note that these percentages do not add up to 100%, because they are not mutually exclusive possibilities). This was particularly surprising, because half of all visible stars are believe to be in [binary systems](https://en.wikipedia.org/wiki/Binary_star), which would make planetary systems very unstable, but some binary systems have been [found to have planets](http://physicsworld.com/cws/article/news/2014/oct/31/planet-forming-stream-found-in-binary-star-system) too.

So indeed it seems *the majority* of stars have planets, but it's very unlikely that all of them do.

However, the exact answer to your question "do we **know** of any stars with no planets" has got to be "no", because there remains a possibility that they have planets that we simply haven't been able to detect, because of [limitations in our techniques](http://blog.thingswedontknow.com/2013/03/detection-and-discovery-of-exoplanets.html) to detect them.

> **Comments:**
> **username_4**: I think there are some important points here.   In my opinion, it should be surprising if a star doesn't have planets, and you'd generally need to give a mechanism for ***why there aren't***.   For example, instability of orbits due to companion stars, or a past pass by a massive object.     Think about this for comparison:   Based evidence from our solar system, it certainly appears that gas giants have many satellites.   A Jupiter with no moon would be very surprising unless you had a reason why it was moonless.   What is different about stellar formation?  
> **username_5**: I just want to add this on Binary systems.   The belief based on observation that most stars were in a binary system was wrong:  http://www.space.com/1995-astronomers-wrong-stars-single.html    Your link mentions that as well, and goes on to talk about planets in binary systems:  https://en.wikipedia.org/wiki/Binary_star#Research_findings  
> **username_6**: The percentages quoted are lower limits, because they refer to the percentage of stars that have planets *within a certain (fairly small) orbital separation*. We really don't know of any stars that definitely *don't* have planets.  

---

