On 2 January 1860, French astronomer Urbain Le Verrier announced the discovery of Vulcan, a hypothetical planet inside the Mercury orbit, to a meeting of the Académie des Sciences in Paris.
On November 20, 1889, American astronomer Edwin Hubble was born. He is best known for his role in establishing the field of extragalactic astronomy and is generally regarded as one of the most important observational cosmologists of the 20th century.
On October 5, 1644 (or according to the old julian calendar September 25), Danish astronomer Ole Christensen Rømer was born. He is best known for making the first quantitative measurements of the speed of light.
On October 2, 1608, German-Dutch lensmaker Hans Lippershey applied to the States-General of the Netherlands on October 2, 1608, for a patent for his instrument "for seeing things far away as if they were nearby".
On July 13, 1527, Welsh mathematician, astronomer, astrologer, occultist, navigator, imperialist and consultant to Queen Elizabeth I, John Dee was born. He is considered one of the most learned men of his age. Besides being an ardent promoter of mathematics and a respected astronomer, in his later years he immersed himself in the worlds of magic, astrology and Hermetic philosophy. One of his aims was attempting to commune with angels in order to learn the universal language of creation.
On June 26, 1730, French astronomer Charles Messier was born. He is best known for his publication of an astronomical catalogue consisting of nebulae and star clusters that came to be known as the 110 "Messier objects". The purpose of the catalogue was to help astronomical observers, in particular comet hunters such as himself, distinguish between permanent and transient visually diffuse objects in the sky.
On June 6, 1436, German mathematician, astronomer, astrologer, translator, instrument maker and Catholic bishop Johannes Müller aus Königsberg was born, better known under the Latinized version of his name as Regiomontanus. His diligent and accurate observations, measurements and recordings paved the way for modern astronomers such as Tycho Brahe and Nikolaus Copernicus.
On March 31, 1596, French philosopher, mathematician, and writer René Descartes was born. The Cartesian coordinate system is named after him, allowing reference to a point in space as a set of numbers, and allowing algebraic equations to be expressed as geometric shapes in a two-dimensional coordinate system. He is credited as the father of analytical geometry, the bridge between algebra and geometry, crucial to the discovery of infinitesimal calculus and analysis.
On March 28, 1749, French mathematician and astronomer Pierre Simon marquis de Laplace was born, whose work was pivotal to the development of mathematical astronomy and statistics. One of his major achievements was the conclusion of the five-volume Mécanique Céleste (Celestial Mechanics) which translated the geometric study of classical mechanics to one based on calculus, opening up a broader range of problems.
On February 19, 1473, Renaissance mathematician and astronomer Nikolaus Copernicus, who established the heliocentric model, which placed the Sun, rather than the Earth, at the center of the universe, was born.