Anders Johan Lexell
Who was Anders Johan Lexell?
Russian mathematician (1740-1784)
Biographical data adapted from Wikipedia’s article on Anders Johan Lexell (CC BY-SA 4.0).
Biography
Anders Johan Lexell was born on 24 December 1740 in Turku, Finland, which was part of the Swedish Empire at the time. As a Finnish-Swedish astronomer, mathematician, and physicist, he spent most of his career in Imperial Russia, where he was known as Andrei Ivanovich Leksel. He became one of the most productive scientists of the eighteenth century, and his work in mathematics and astronomy earned him respect from top intellectuals of his time.
Lexell studied at the Royal Academy of Turku, where he built the mathematical skills that shaped his future contributions. He later joined the Russian Academy of Sciences in Saint Petersburg, an institution thriving under Leonhard Euler. Lexell published 66 papers over 16 years at the Academy, making him one of its most active contributors. His work covered polygonometry, spherical trigonometry, celestial mechanics, and the calculation of planetary and cometary paths.
His research in celestial mechanics gained international attention. Lexell closely examined comet paths, especially focusing on the object later named Lexell's Comet, which he found had come closer to Earth than any other known comet. He also played a key role in studying the 1769 transit of Venus, using it to improve calculations of the solar parallax, crucial for measuring the solar system's scale. His published work on this transit is one of his most referenced.
Lexell had a strong personal and professional bond with Leonhard Euler, a leading mathematician of the century. He was at Euler's home when Euler died in 1783 and was chosen to succeed him as chair of the mathematics department at the Russian Academy of Sciences. Unfortunately, Lexell died less than a year later, on 11 December 1784, in Saint Petersburg, ending what was already an accomplished career. Daniel Bernoulli praised his work, and Euler reportedly noted that only D'Alembert or himself could have written some of Lexell's papers.
Lexell never married. He stayed close to the Euler family during his time in Saint Petersburg. Although he spent much of his life in Russia, his contemporary Henrik Gabriel Porthan noted that Lexell retained his Finnish identity. He is remembered as the first Finnish-born researcher to gain significant international recognition in mathematics and astronomy. The asteroid 2004 Lexell and the lunar crater Lexell are named in his honor.
Before Fame
Anders Johan Lexell was born and grew up in Turku, which was the main intellectual and administrative hub of Finnish territory when it was under Swedish rule. He studied at the Royal Academy of Turku, the oldest university in Finland, where he got strong training in mathematics and the natural sciences. The academy linked its students to the wider trends in European scientific thought, especially at a time when minds like Euler, Lagrange, and D'Alembert were transforming mathematics and mechanics.
After his studies, Lexell's skills gained attention beyond Scandinavia. He moved to Saint Petersburg, placing him in one of Europe's top scientific centers, the Russian Academy of Sciences. Supported by the Russian imperial court, it attracted skilled researchers from all over Europe. When he arrived there in the late eighteenth century, Lexell had access to both the resources and the collaborative setting he needed to advance his research in astronomy, spherical trigonometry, and the mathematics of orbital motion.
Key Achievements
- Discovered and analyzed the trajectory of Lexell's Comet, determining it had made the closest recorded cometary approach to Earth
- Contributed refined calculations of solar parallax through analysis of the 1769 transit of Venus
- Developed new solutions in spherical trigonometry, which became the basis for his comet and planet motion research
- Named successor to Leonhard Euler as chair of the mathematics department at the Russian Academy of Sciences
- Recognized as the first Finnish-born researcher to make a major international contribution to mathematics and astronomy
Did You Know?
- 01.Lexell was present at Leonhard Euler's home on the day Euler died in 1783 and was appointed to succeed him as chair of mathematics at the Russian Academy of Sciences.
- 02.Lexell's Comet, which he analyzed in detail, passed closer to Earth than any other comet in recorded observational history.
- 03.La Grande Encyclopédie specifically identified Lexell as the most prominent mathematician of his time in the field of spherical trigonometry.
- 04.Lexell published 66 scientific papers during his 16 years at the Russian Academy of Sciences, an unusually high output for the period.
- 05.Although he spent his entire career in Russia, the Finnish scholar Henrik Gabriel Porthan noted that Lexell remained 'Finnish at heart' throughout his life.