Question: When was the celestial body that all objects focus on according to Kepler's laws discovered to be the center of the solar system?

Context paragraphs:
paragraph_text: The Kuiper belt (/ ˈkaɪpər / or Dutch pronunciation: ('kœy̯pər)), occasionally called the Edgeworth -- Kuiper belt, is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger -- 20 times as wide and 20 to 200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed. While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed ``ices ''), such as methane, ammonia and water. The Kuiper belt is home to three officially recognized dwarf planets: Pluto, Haumea and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region.
title: Kuiper belt
paragraph_text: The galactic year, also known as a cosmic year, is the duration of time required for the Sun to orbit once around the center of the Milky Way Galaxy. Estimates of the length of one orbit range from 225 to 250 million terrestrial years. The Solar System is traveling at an average speed of 828,000 km / h (230 km / s) or 514,000 mph (143 mi / s) within its trajectory around the galactic center, a speed at which an object could circumnavigate the Earth's equator in 2 minutes and 54 seconds; that speed corresponds to approximately one 1300th of the speed of light.
title: Galactic year
paragraph_text: Kepler-10c is an exoplanet orbiting the G-type star Kepler-10, located around 568 light-years away in Draco. Its discovery was announced by Kepler in May 2011, although it had been seen as a planetary candidate since January 2011, when Kepler-10b was discovered. The team confirmed the observation using data from NASA's Spitzer Space Telescope and a technique called Blender that ruled out most false positives. Kepler-10c was the third transiting planet to be confirmed statistically (based on probability rather than actual observation), after Kepler-9d and Kepler-11g. The Kepler team considers the statistical method that led to the discovery of Kepler-10c as what will be necessary to confirm many planets in Kepler's field of view.
title: Kepler-10c
paragraph_text: Newton's First Law of Motion states that objects continue to move in a state of constant velocity unless acted upon by an external net force or resultant force. This law is an extension of Galileo's insight that constant velocity was associated with a lack of net force (see a more detailed description of this below). Newton proposed that every object with mass has an innate inertia that functions as the fundamental equilibrium "natural state" in place of the Aristotelian idea of the "natural state of rest". That is, the first law contradicts the intuitive Aristotelian belief that a net force is required to keep an object moving with constant velocity. By making rest physically indistinguishable from non-zero constant velocity, Newton's First Law directly connects inertia with the concept of relative velocities. Specifically, in systems where objects are moving with different velocities, it is impossible to determine which object is "in motion" and which object is "at rest". In other words, to phrase matters more technically, the laws of physics are the same in every inertial frame of reference, that is, in all frames related by a Galilean transformation.
title: Force
paragraph_text: The galactic year, also known as a cosmic year, is the duration of time required for the Sun to orbit once around the center of the Milky Way Galaxy. Estimates of the length of one orbit range from 225 to 250 million terrestrial years. The Solar System is traveling at an average speed of 828,000 km / h (230 km / s) or 514,000 mph (143 mi / s) within its trajectory around the galactic center, a speed at which an object could circumnavigate the Earth's equator in 2 minutes and 54 seconds; that speed corresponds to approximately 1 / 1300 of the speed of light.
title: Galactic year
paragraph_text: Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. The concentrated heat is then used as a heat source for a conventional power plant. A wide range of concentrating technologies exists; the most developed are the parabolic trough, the concentrating linear fresnel reflector, the Stirling dish and the solar power tower. Various techniques are used to track the Sun and focus light. In all of these systems a working fluid is heated by the concentrated sunlight, and is then used for power generation or energy storage.
title: Solar energy
paragraph_text: NGC 210 is a barred spiral galaxy located roughly 67 million light-years from the Solar System in the constellation Cetus. It was discovered on October 3, 1785 by William Herschel and later added to the New General Catalogue.
title: NGC 210
paragraph_text: There are 69 known moons of Jupiter. This gives Jupiter the largest number of moons with reasonably stable orbits of any planet in the Solar System. The most massive of the moons are the four Galilean moons, which were independently discovered in 1610 by Galileo Galilei and Simon Marius and were the first objects found to orbit a body that was neither Earth nor the Sun. From the end of the 19th century, dozens of much smaller Jovian moons have been discovered and have received the names of lovers or daughters of the Roman god Jupiter or his Greek equivalent Zeus. The Galilean moons are by far the largest and most massive objects to orbit Jupiter, with the remaining 65 known moons and the rings together comprising just 0.003% of the total orbiting mass.
title: Moons of Jupiter
paragraph_text: Heliocentrism is the astronomical model in which the Earth and planets revolve around the Sun at the center of the Solar System. Historically, Heliocentrism was opposed to geocentrism, which placed the Earth at the center. The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BC by Aristarchus of Samos, but at least in the medieval world, Aristarchus's Heliocentrism attracted little attention -- possibly because of the loss of scientific works of the Hellenistic Era.
title: Heliocentrism
paragraph_text: For many thousands of years, astronomers maintained a geocentric world view and did not recognize the existence of a Solar System. Most believed Earth was stationary at the center of the Universe and categorically different from the divine or ethereal objects that moved through the sky. Although the Greek philosopher Aristarchus of Samos had speculated on a heliocentric reordering of the cosmos, Nicolaus Copernicus in the 16th century developed a mathematically predictive heliocentric system. His 17th - century successors, Galileo Galilei, Johannes Kepler, and Isaac Newton, developed a modern understanding of physics that led to the gradual acceptance of the idea that Earth moves around the Sun and that the planets are governed by the same physical laws that govern Earth. In more recent times, this led to the investigation of geological phenomena such as mountains and craters and seasonal meteorological phenomena such as clouds, dust storms, and ice caps on the other planets.
title: Discovery and exploration of the Solar System
paragraph_text: Kepler's laws of planetary motion describe the orbits of objects about the Sun. Following Kepler's laws, each object travels along an ellipse with the Sun at one focus. Objects closer to the Sun (with smaller semi-major axes) travel more quickly because they are more affected by the Sun's gravity. On an elliptical orbit, a body's distance from the Sun varies over the course of its year. A body's closest approach to the Sun is called its perihelion, whereas its most distant point from the Sun is called its aphelion. The orbits of the planets are nearly circular, but many comets, asteroids, and Kuiper belt objects follow highly elliptical orbits. The positions of the bodies in the Solar System can be predicted using numerical models.
title: Solar System
paragraph_text: Wilhelm Schickard (22 April 1592 – 24 October 1635) was a German professor of Hebrew and Astronomy who became famous in the second part of the 20th century after Dr. Franz Hammer, a biographer (along with Max Caspar) of Johannes Kepler, claimed that the drawings of a calculating clock, predating the public release of Pascal's calculator by twenty years, had been discovered in two unknown letters written by Schickard to Johannes Kepler in 1623 and 1624.
title: Wilhelm Schickard
paragraph_text: Most planetary orbits are nearly circular, and careful observation and calculation are required in order to establish that they are not perfectly circular. Calculations of the orbit of Mars, whose published values are somewhat suspect, indicated an elliptical orbit. From this, Johannes Kepler inferred that other bodies in the Solar System, including those farther away from the Sun, also have elliptical orbits.
title: Kepler's laws of planetary motion
paragraph_text: On 14 December 2017, NASA and Google announced the discovery of an eighth planet, Kepler - 90i, in the Kepler - 90 system: the discovery was made using a new machine learning method developed by Google.
title: Kepler-90
paragraph_text: Charles Thomas Kowal (November 8, 1940 – November 28, 2011) was an American astronomer known for his observations and discoveries in the Solar System. As a staff astronomer at Caltech's Mount Wilson and Palomar Mountain observatories between 1961 and 1984, he found the first of a new class of Solar System objects, the centaurs, discovered two moons of the planet Jupiter, and discovered or co-discovered a number of asteroids, comets and supernovae. He was awarded the James Craig Watson Medal for his contributions to astronomy in 1979.
title: Charles T. Kowal
paragraph_text: GD 40 is a white dwarf in the constellation Cetus. The star's spectrum has been found to show traces of external of metal contamination due to disruption of an extrasolar dwarf planet or an asteroid. The disrupted object should have had roughly the same mass of the Solar System asteroid 3 Juno.
title: GD 40
paragraph_text: The assumption that black-body radiation is thermal leads to an accurate prediction: the total amount of emitted energy goes up with the temperature according to a definite rule, the Stefan–Boltzmann law (1879–84). But it was also known that the colour of the light given off by a hot object changes with the temperature, so that "white hot" is hotter than "red hot". Nevertheless, Wilhelm Wien discovered the mathematical relationship between the peaks of the curves at different temperatures, by using the principle of adiabatic invariance. At each different temperature, the curve is moved over by Wien's displacement law (1893). Wien also proposed an approximation for the spectrum of the object, which was correct at high frequencies (short wavelength) but not at low frequencies (long wavelength). It still was not clear why the spectrum of a hot object had the form that it has (see diagram).
title: Planck constant
paragraph_text: Valles Marineris (Latin for "Mariner Valleys", named after the "Mariner 9" Mars orbiter of 1971–72 which discovered it) is a system of canyons that runs along the Martian surface east of the Tharsis region. At more than long, wide and up to deep, Valles Marineris is one of the largest canyons of the Solar System, surpassed in length only by the rift valleys of Earth.
title: Valles Marineris
paragraph_text: Kepler-4 is a sunlike star located about 1610 light-years away in the constellation Draco. It is in the field of view of the Kepler Mission, a NASA operation purposed with finding Earth-like planets. Kepler-4b, a Neptune-sized planet that orbits extremely close to its star, was discovered in its orbit and made public by the Kepler team on January 4, 2010. Kepler-4b was the first discovery by the Kepler satellite, and its confirmation helped to demonstrate the spacecraft's effectiveness.
title: Kepler-4
paragraph_text: Kepler-452b (a planet sometimes quoted to be an Earth 2.0 or Earth's Cousin based on its characteristics; known sometimes as Coruscant by NASA, also known by its Kepler Object of Interest designation KOI-7016.01) is an exoplanet orbiting the Sun-like star Kepler-452 about 1,402 light-years (430 pc) from Earth in the constellation Cygnus. It was identified by the Kepler space telescope, and its discovery was announced by NASA on 23 July 2015. However, a study in 2018 by Mullally et al. implied that statistically, Kepler-452b has not been proven to exist and must still be considered a candidate. It is the first potentially rocky super-Earth planet discovered orbiting within the habitable zone of a star very similar to the Sun.The planet is about 1,400 light-years away from the Solar System. At the speed of the New Horizons spacecraft, about 59,000 km/h (37,000 mph), it would take approximately 26 million years to get there.
title: Kepler-452b

Reasoning steps:
What do all objects focus on according to Kepler's laws? >>>> Sun
when was the Sun discovered to be the center of the solar system >>>> as early as the 3rd century BC

Answer: spans: as early as the 3rd century BC