Argelander, FWA
NAME: Argelander, Friedrich Wilhelm August
ACHIEVEMENTS: Publication of the Bonner Durchmusterung, an enormous catalog of stars.
NICKNAME/ALIAS:
DATE AND PLACE OF BIRTH: 22 March, 1799, Memel, East Prussia
DATE/PLACE OF DEATH/AGE AT DEATH: 17 February, 1875, Bonn. Aged 75.
DISCIPLINE: Astronomer
FIELD: Astronomy
LANGUAGE: German
PARENTS: Johann Gottlieb Argelander, Dorothea Wilhelmine Gruenlingen
SIBLINGS: ?
SPOUSE: ?
CHILDREN: ?
EDUCATION: University of Koenigsberg, Prussia
MAJOR WORK: Bonner Durchmusterung (1859-1862, republished 1950)
LIFE AND TIMES:
The early life of F.W.A. Argelander is a classic tale of mentoring. Argelander’s father was a wealthy and influential merchant who opened his home to the exiled crown prince of Prussia during the Napoleonic wars. Patriotic young Argelander determined to become a political economist, but at the University of Koenigsberg he attended some lectures given by the great astronomer Bessel* and was strongly attracted to the subject. Before long, Argelander was performing calculations at the University’s observatory under Bessel’s supervision, and Bessel talked him into taking a position as one of his assistants.
When a position became available at the Abo Observatory in Finland, Bessel recommended the ex-political science “major” who had become one of his “most outstanding students” for the post of observer. At the age of 24, Argelander determined to make Abo a world class observatory. Since Bessel had chosen to investigate the position of the stars, Argelander decided to focus on the motion of the stars over time.
When Abo Observatory burned down in 1827, Argelander continued his researches at Helsinki and in 1837 he published a full report of his researches. In his report, he emphasized the implications of stellar movement on the movement of the sun and the solar system, deducing that the sun itself followed a path throughout space just like any other star. Accordingly, Argelander attempted to discover this path.
In the meantime, he was invited to join the faculty of the Prussian University at Bonn. The Crown Prince, whom his father befriended so many years earlier, was now King Friedrich Wilhelm IV, and Argelander was promised funds to upgrade the observatory to meet his requirements.
In 1843, he published “Uranometria nova” a catalog of stars including a new rating of magnitude. Argelander developed a system for estimating the brightness of stars with the naked eye (photometry did not yet exist) and included this rating of each star’s magnitude along with each star’s entry.
Not only did this add to the body of information about the stars, but it also allowed comparisons to be made so that future observers could investigate the changes over time in the brightness of a star. Such scales had already been used by Tycho Brahe, but Argelander expanded them and made them more consistent.
With this background and a new telescope at his disposal, Argelander was now ready for his greatest achievement.
Bessel had begun to catalog the stars visible in the northern sky and Argelander would add considerably to this work. First, Argelander limited himself to stars of a certain brightness, the ninth magnitude (on a scale of one to ten where ten is the dimmest). Then he and his assistants began the enormous task of observing and recording these stars. In total, they made over a million observations and recorded the position and magnitude of 324,188 stars. This set of observations was published as the Bonner Durchmusterung, the Bonn Survey (or “scanning through”).
But Argelander’s task wasn’t complete yet. He had gone as far as he could with the resources at his disposal, and the only further step was to involve other observatories.
In 1867, he proposed the Astronomische Gesellschaft, in which a number of observatories would, over time, expand the work begun by the Bonner Durchmustering. The work would not be complete until after Argelander’s death. Indeed, “AG3”, the third catalog supplementing Argelander’s work, would not be published until 1969.
ASSESSMENT: Argelander did not provide any grand cosmological theories, but he provided the observations required to suggest and verify great scientific theories.
EXTRA CONNECTIONS: None
ONELINER: FWA Argelander, great unsung astronomer
BIBLIOGRAPHY:
EB, DSB