Hevelianum takes its name from Johannes Hevelius – an astronomer from Gdańsk, and one of the greatest men of science of the 17th century. On 28 January 2021 we celebrate his 410th birthday.
Can you run a brewery and watch the sky from its roof? Grow lemons and build telescopes? Be a member of the city council and write great astronomical works? Johannes Hevelius proved that all this could be done. The range of his interests was impressive, although he is best remembered as an astronomer. The equally interdisciplinary Hevelianum, combining popularisation of the natural and mathematical sciences with the history of Gdańsk and military architecture, chose to take its name from him.
His wealthy father provided Hevelius with a comprehensive education. He was introduced to astronomy by Piotr Krüger, one of the most eminent Gdańsk mathematicians and a well-known astronomer and professor of the Academic Gymnasium. Hevelius studied law and economics in Leiden. Between 1631 and 1634 he travelled around England and France. During his travels he met many scientists with whom he later corresponded.
After returning to Gdańsk, Hevelius took over the family breweries (he brewed that famous Gdańsk speciality – Jopen beer, which is a kind of thick and nutritious syrupy beer valued for its health properties). His first wife, Katarzyna, helped him run the business. He was a member of the brewers’ guild and the city council. At the age of forty, he became a lifetime councillor in Gdańsk. He was still occupied with astronomy at the same time
After 1650 he built an observatory on the roofs of his three tenement houses on Korzenna Street, creating a terrace measuring approximately 14 by 7 metres (46′ by 23′). He had so many instruments that it soon became known as one of the best equipped observatories in Europe. It was visited by scholars and kings – John II Casimir and John III Sobieski. To the latter, to celebrate his election, Hevelius sent… some lemons he had grown.
As a great constructor, he usually built and decorated his astronomical instruments himself, just like he polished the lenses for the telescopes. The numerous quadrants, sextants and octants for angular measurements were very precisely made, which caused admiration and sometimes even disbelief among astronomers.
In May 1679 the famous Edmond Halley, a member of the Royal Astronomical Society, to which Hevelius belonged, came to Gdańsk to verify the accuracy of Hevelius’ instruments. Astronomers checked the observations using different instruments, and their measurements showed the same level of precision. Hevelius considered Halley’s visit to be one of the happiest moments of his life.
Johannes Hevelius was an extremely hard-working and precise observer, making tens of thousands of observations of various celestial bodies. He published his results in several books, such as: ‘Selenographie’, which meticulously described the surface of the moon, or ‘Machina coelestis’, one of the most important textbooks about the universe in human history.
In 1683, to commemorate the victory of Sobieski’s Polish army at Vienna, Hevelius gave a newly described constellation the name Sobieski’s Shield. The other constellations named by Hevelius are: Lacerta, Vulpecula, Leo Minor, Canes Venatici, Lynx and Sextans. The International Astronomical Union approved all of them in the 20th century, and they are all commonly accepted to this day.
Hevelius’ second wife – Elisabeth – not only helped him manage the brewery. She also conducted astronomical observations and research alongside him, and corresponded with many European scientists. She collaborated with her husband on the work ‘Prodromus astronomiae’ (a catalogue of 1564 stars and their positions), completing the book after his death as well as introducing numerous corrections to it. Johannes Hevelius died on 28 January 1687, on his 76th birthday. He was buried in St Catherine’s Church in Gdańsk. After the death of Hevelius, Elisabeth published three more works based on the collected materials. Elisabeth dedicated one of them – ‘Firmamentum Sobiescianum’ – to King John III Sobieski and signed it ‘Elisabeth, widow of Hevelius’.