What is the reason behind Jupiter not orbiting the Sun?
Unlike the other planets in our solar system, Jupiter never orbits Sun technically.
Practically, not only Jupiter, but every planet in our solar system does not orbit our sun.
But the size and weight are so small that it is almost negligible, and it is almost the centre of the Sun.
But for Jupiter, it is not the same. Jupiter and Sun both orbit a point that lies outside the sun. And this point is known as “Barycenter”.
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What is a Barycenter?
A barycenter is the centre of gravity of two or more bodies that are orbiting each other. It is the point around which their orbits rotate. For example, the barycenter of the Earth and the Moon is about 3000 kilometres (km) from the centre of the Earth, near its surface.
When astronomers talk about the barycenter of a planetary system, they are usually referring to the barycenter of the star and the planet. For example, the barycenter of the Sun and Jupiter is about 730,000 km from the centre of the Sun.
The barycenter of a binary star system is the point around which the two stars orbit each other. It is usually located between the two stars. For example, the barycenter of Sirius A and Sirius B, the two brightest stars in the night sky, is about 20 AU (astronomical units) from Sirius A.
The barycenter of a multiple star system is the point around which all the stars orbit each other. It is usually located at the centre of the mass of the system.
The barycenter of the Milky Way galaxy is about 27,000 light-years from the centre of the galaxy.
Let’s know the reason behind this behaviour of Jupiter.
Mainly, there are two reasons behind this phenomenon.
The first reason is the size of Jupiter. Undoubtedly, Jupiter is the biggest planet in our solar system. For its gigantic size, it doesn’t orbit the sun. It has a radius of 69,911 km. For your clearance, Earth’s radius is 3,959 km and the radius of the Sun is 6,95,842 km.
That means Jupiter is just 0.1004% smaller than Sun in size whereas earth is 0.0056% smaller than Sun.
Although this is not massive as the sun also it is not a very small planet. Even some researchers say that if Jupiter was a little bit more huge, then maybe we were living in a binary solar system.
Binary star system: If in a solar system, there are two stars in the place of one single star, and they revolve around themselves, then this type of star system is called a binary star system.
Here, in this image, you can see clearly how big is Jupiter. And how small we are.
While talking about mass, it is also quite amazing.
Jupiter’s mass is 1.89* 1027, while Sun’s maas is 1.98*1030. Jupiter carries almost 0.00024% mass of the sun.
Also, Jupiter carries a tremendous amount of mass to our solar system.
So, these are the two reasons, why Jupiter technically doesn’t orbit Sun.
So, with Jupiter’s gigantic size and its mass, Jupiter pulls the centre of mass toward itself and the shifted point is called the ‘Barycenter’. This barycenter is around 48280.32 km far from the Sun’s surface. So it is not negligible.
And for this size and mass, earth and other small planets’ barycenters are negligible.
Hope you like this.
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