What if Sirius A and B were 1 light year away from our solar system?

[Vivaldi]

Do our planets have any gravitational force at all from Sirius Star System?

If not, how much closer should they get in order to start causing a gravitional force?

[slatyb]

None at all. Neptune is 4 light-hours from the sun. This is less than 1/2000th of a light-year.

[Vivaldi]

What does Neptun have anything to do with how far it is from Sun?

[Vivaldi]

Far far far more away from Pluto, there are dwarf planets which rotate around Sun.

What does Neptun have anything to do?

[slatyb]

Neptune is the farthest planet and a star one light -year from the sun would have no measurable effect on Neptune.

[Vivaldi]

There are dwarf planets so much more more more further away from Neptun

[Vivaldi]

Neptun isn't the last thing on Solar System.

Go learn it first

[Vivaldi]

Possible Dwarf Planet Sedna is at 130 billion kilometers from Sun.

There are dwarf planets in solar system , which are extremely further away from Pluto.

[slatyb]

Still a small fraction of a light-year away.

[Vivaldi]

Estimated to be 140 billion km when the dwarf planet is furthest away from Sun. That is still crazy.

[Vivaldi]

Outer edge of Solar System is Oort Cloud, which goes as far as 0.8 light years away from Sun.

[slatyb]

You said "planets". The Oort cloud is not known to exist, and is not theorized to contain planets.

[Vivaldi]

Isn't it about any gravitational force of Sun?

Astroids, Dwarf Planes, Planets, all are rotating around our Sun. You don't even count Dwarf Planets, talking as if Neptun was the last object rotating around Sun.

[Vivaldi]

Furthest away dwarf planete estimated to have a distance of 140 billion km from Sun when it is furthest. It is 31 times further away from Neptun.

As for oort cloud, it is where the gravitiy of sun ends, doesn't it?

[Vivaldi]

This is what Nasa says:

If you measure by edge of the Sun's magnetic fields, the end is the heliosphere. If you judge by the stopping point of Sun's gravitational influence, the solar system would end at the Oort Cloud.