The boundaries of solar system are not exactly defined. See wiki:exxon_valdez said:What is the method of calculating the diameter of a solar system knowing each of its planets distance to the star?
The point at which the Solar System ends and interstellar space begins is not precisely defined because its outer boundaries are shaped by two forces, the solar wind and the Sun's gravity. The limit of the solar wind's influence is roughly four times Pluto's distance from the Sun; this heliopause, the outer boundary of the heliosphere, is considered the beginning of the interstellar medium.[63] The Sun's Hill sphere, the effective range of its gravitational dominance, is thought to extend up to a thousand times farther and encompasses the hypothetical Oort cloud.
Much of the Solar System is still unknown. The Sun's gravitational field is estimated to dominate the gravitational forces of surrounding stars out to about two light years (125,000 AU). Lower estimates for the radius of the Oort cloud, by contrast, do not place it farther than 50,000 AU.
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Currently, the furthest known objects, such as Comet West, have aphelia around 70,000 AU from the Sun, but as the Oort cloud becomes better known, this may change.
Surely not, see previous quotes.exxon_valdez said:Is it a matter of doubling the distance of the furthest planet?
The diameter of our solar system is approximately 287 billion kilometers. This measurement includes the distance from the Sun to the farthest known objects in our solar system, such as the dwarf planet Eris.
The distance between objects in our solar system is calculated using a unit of measurement called astronomical units (AU). 1 AU is equal to the average distance between the Earth and the Sun, which is about 149.6 million kilometers. Scientists also use other units, such as light-years, to measure distances in space.
Yes, the same method of using astronomical units and other units of measurement can be used to calculate distances in multi-star systems. However, the distances may be much greater and more complex to calculate due to the gravitational interactions between multiple stars.
Scientists use a technique called interferometry to measure the diameter of stars in multi-star systems. This involves combining the light from multiple telescopes to create a larger virtual telescope, allowing for more precise measurements of the stars' diameters.
No, the diameter of the solar system is constantly changing due to the orbits of planets and other objects. For example, when Earth is at its closest point to the Sun (perihelion), the diameter of the solar system is slightly smaller than when it is at its farthest point (aphelion).