<p>A consensus number is that there roughly $10^{11}$ stars in our Galaxy (though this number is certainly uncertain by a factor of at least two, because it is based on extrapolating what we know about stellar populations in our vicinity). Most of these stars are of lower mass and are much less luminous than the Sun.</p>

<p>The number of planets is even more uncertain. It now seems probable that most stars like the Sun have at least one planet, but we really don't know that much about the diversity of planetary systems, how typical something like the solar system is, or how planetary systems might change as a function of position in the Galaxy. We also don't know that much about planetary systems around the dominant (by number) very low-mass stars. They certainly can have planetary systems, but the fraction that do is still a work in progress.</p>

CC BY-SA 3.0
2016-01-21T12:11:35.057Z
2016-01-21T12:11:35.057Z
ProfRob
<p>The number of stars and planets in the milky way can only be given in approximate values.There are about 100-400 billion stars and as of 2016 there are about 2097 planets discovered from 1337 planetary systems. </p>

CC BY-SA 3.0
2016-03-22T09:45:09.850Z
I think you may have made up the number when you say 1337. Too much of a coinsidence.
SE - stop firing the good guys
CC BY-SA 3.0
2016-03-23T05:09:01.853Z
I got that number from wikipedia! <http://en.wikipedia.org/wiki/Planetary_system>
Astrofun
CC BY-SA 3.0
2016-03-23T06:07:42.947Z
http://exoplanets.org/ claims 5428. http://exoplanet.eu/ has 2097
Wayfaring Stranger
CC BY-SA 3.0
2016-03-23T07:12:17.963Z
Obviously, this number keeps increasing. It is irrelevant in answering this question, since it is a vanishingly small fraction of the total number.
ProfRob
CC BY-SA 3.0
2016-03-24T02:09:10.590Z
@RobJeffries One can only build up a statistically useful estimate by sampling. Of course the sampling method used, light curves or stellar wobbling makes a difference in how you have to do the calculation. 100 billion planets http://www.nasa.gov/multimedia/imagegallery/image_feature_2233.html or 8.8 billion earth like planets http://www.nbcnews.com/science/8-8-billion-habitable-earth-size-planets-exist-milky-way-8C11529186 I expect those numbers will be considerably refined over the next couple decades.
Wayfaring Stranger
CC BY-SA 3.0
2016-03-24T07:31:56.073Z
@WayfaringStranger That was my point. Simply stating how many planets have been discovered does not answer the question. The first number you quote in your comment is simply made up since we know almost  *nothing* about the frequency of planets around the most common type of star. The second is hugely uncertain (2 sig figs is absurd). Both are dependent on how many stars are assumed to be present!
ProfRob
CC BY-SA 3.0
2016-03-25T01:17:39.770Z
There are exactly 221,560,742,983 stars in the Milky Way, with one exploding tomorrow, and 576,980,702,675 planets not counting dwarfs. I asked God.
Jack R. Woods
CC BY-SA 3.0
2016-03-22T06:50:02.137Z
2016-03-23T06:16:17.510Z
2016-03-23T06:16:17.510Z
Astrofun
<p>Is there any specific numbers on stars &amp; planets count on Milky Way Galaxy ?</p>

CC BY-SA 3.0
2016-03-22T09:47:01.440Z
There are only very rough approximates available.
SE - stop firing the good guys
CC BY-SA 3.0
2016-03-22T10:25:04.683Z
@Hohmannfan Not particularly wishing to start an argument, but what is the purpose of your comment, given that both answers make exactly that same point very clearly?
ProfRob
<star><planet><milky-way><estimate>
Number of stars & planets in Milky Way Galaxy?
Mani
# Number of stars & planets in Milky Way Galaxy?

(Asked by: username_0 on 2016-01-21)

Is there any specific numbers on stars & planets count on Milky Way Galaxy ?

**Tags:** star, planet, milky-way, estimate

> **Comments:**
> **username_1**: There are only very rough approximates available.  
> **username_2**: @Hohmannfan Not particularly wishing to start an argument, but what is the purpose of your comment, given that both answers make exactly that same point very clearly?  

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## 2 answers

### Answer by username_2 on 2016-01-21. Score: 2

A consensus number is that there roughly $10^{11}$ stars in our Galaxy (though this number is certainly uncertain by a factor of at least two, because it is based on extrapolating what we know about stellar populations in our vicinity). Most of these stars are of lower mass and are much less luminous than the Sun.

The number of planets is even more uncertain. It now seems probable that most stars like the Sun have at least one planet, but we really don't know that much about the diversity of planetary systems, how typical something like the solar system is, or how planetary systems might change as a function of position in the Galaxy. We also don't know that much about planetary systems around the dominant (by number) very low-mass stars. They certainly can have planetary systems, but the fraction that do is still a work in progress.


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### Answer by username_3 on 2016-03-22. Score: -1

The number of stars and planets in the milky way can only be given in approximate values.There are about 100-400 billion stars and as of 2016 there are about 2097 planets discovered from 1337 planetary systems.

> **Comments:**
> **username_1**: I think you may have made up the number when you say 1337. Too much of a coinsidence.  
> **username_3**: I got that number from wikipedia! <http://en.wikipedia.org/wiki/Planetary_system>  
> **username_4**: http://exoplanets.org/ claims 5428. http://exoplanet.eu/ has 2097  
> **username_2**: Obviously, this number keeps increasing. It is irrelevant in answering this question, since it is a vanishingly small fraction of the total number.  
> **username_4**: @RobJeffries One can only build up a statistically useful estimate by sampling. Of course the sampling method used, light curves or stellar wobbling makes a difference in how you have to do the calculation. 100 billion planets http://www.nasa.gov/multimedia/imagegallery/image_feature_2233.html or 8.8 billion earth like planets http://www.nbcnews.com/science/8-8-billion-habitable-earth-size-planets-exist-milky-way-8C11529186 I expect those numbers will be considerably refined over the next couple decades.  
> **username_2**: @WayfaringStranger That was my point. Simply stating how many planets have been discovered does not answer the question. The first number you quote in your comment is simply made up since we know almost  *nothing* about the frequency of planets around the most common type of star. The second is hugely uncertain (2 sig figs is absurd). Both are dependent on how many stars are assumed to be present!  
> **username_5**: There are exactly 221,560,742,983 stars in the Milky Way, with one exploding tomorrow, and 576,980,702,675 planets not counting dwarfs. I asked God.  

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