With all the number of exoplanets found, have enough exoplanets been found to work out what the average number of planets are in a stars solar system?

Tau.Neutrino said:

With all the number of exoplanets found, have enough exoplanets been found to work out what the average number of planets are in a stars solar system?

I think I calculated that. From the Kepler data. I’ll look back through my notes, if I haven’t already consigned them to the dustbin …

Here’s a quick answer from https://www.planetary.org/explore/the-planetary-report/a-kepler-orrery.html

For stars with two or more known planets (including planet candidates), the average number of planets is 1815/726 = 2.5. The total number of planets + candidates from Kepler includes 2,000 additional single planets systems.

So the average number of planets from Kepler observations is (2000+1815)/(2000+726) = 1.4 exoplanets per star. Kepler observed sunlike stars, not red dwarfs, which makes the data more useful.

This is a tentative and definitely minimum number because Kepler can’t see planets of the star in orbits further away from the star than Mercury’s orbit around the Sun. So we’re talking here about an average of 1.4 exoplanets per solar system inside the orbit of Mercury.

mollwollfumble said:

Tau.Neutrino said:

With all the number of exoplanets found, have enough exoplanets been found to work out what the average number of planets are in a stars solar system?

I think I calculated that. From the Kepler data. I’ll look back through my notes, if I haven’t already consigned them to the dustbin …

Here’s a quick answer from https://www.planetary.org/explore/the-planetary-report/a-kepler-orrery.html

For stars with two or more known planets (including planet candidates), the average number of planets is 1815/726 = 2.5. The total number of planets + candidates from Kepler includes 2,000 additional single planets systems.

So the average number of planets from Kepler observations is (2000+1815)/(2000+726) = 1.4 exoplanets per star. Kepler observed sunlike stars, not red dwarfs, which makes the data more useful.

This is a tentative and definitely minimum number because Kepler can’t see planets of the star in orbits further away from the star than Mercury’s orbit around the Sun. So we’re talking here about an average of 1.4 exoplanets per solar system inside the orbit of Mercury.

Thank you.

Tau.Neutrino said:

mollwollfumble said:

Tau.Neutrino said:

With all the number of exoplanets found, have enough exoplanets been found to work out what the average number of planets are in a stars solar system?

I think I calculated that. From the Kepler data. I’ll look back through my notes, if I haven’t already consigned them to the dustbin …

Here’s a quick answer from https://www.planetary.org/explore/the-planetary-report/a-kepler-orrery.html

For stars with two or more known planets (including planet candidates), the average number of planets is 1815/726 = 2.5. The total number of planets + candidates from Kepler includes 2,000 additional single planets systems.

So the average number of planets from Kepler observations is (2000+1815)/(2000+726) = 1.4 exoplanets per star. Kepler observed sunlike stars, not red dwarfs, which makes the data more useful.

This is a tentative and definitely minimum number because Kepler can’t see planets of the star in orbits further away from the star than Mercury’s orbit around the Sun. So we’re talking here about an average of 1.4 exoplanets per solar system inside the orbit of Mercury.

Thank you.

To clarify a little, Kepler can see planets beyond the orbit of Mercury, sometimes, but the probability of being able to observe a planet drops off faster than linearly with orbital distance, so many more planets would be missed in orbits beyond that of Mercury.