28:T448,

In the cloister of the Patio de Escuelas Menores of Salamanca, there is a mural known as El Cielo de Salamanca (The Sky of Salamanca) depicting some Ptolemaic constellations, the Sun and Mercury. It is part of a painting (c. 1483–86) that was hidden for a century and a half. Rediscovered in 1901, it was moved to its current location in 1953. Those who visited it shortly after its completion describe it as a magnificent astrological vault. However, in 1960, Zinner stated that the mural was a representation of the celestial vault of an August day in 1475. This interpretation has been taken as a fact ever since. Here it is shown that it is a speculative proposal with many inconsistencies. The authors consider that the painting is an iconographic representation with astrological motifs depicting the planets in their houses or domiciles according to the Tetrabiblos. Based on this new interpretation, consistent with what was taught in Salamanca at that time, the article proposes what the original painting may have looked like.

29:T424,

German astronomer Max Wolf (1863–1932) pioneered photographic observation of asteroids and is credited as the discoverer of Trojan asteroids in 1906. His partnership with the Austro-Hungarian Empire astronomer Johann Palisa for visual confirmation led to the suggestion to call these bodies, with apparently common properties, “Trojans.” Wolf’s systematic approach led the Heidelberg-Königstuhl Observatory to be a world power in asteroid discovery around the turn of the twentieth century and led to the recognition of a new orbital class. E. E. Barnard had made an isolated observation of a Trojan in 1904, but the credit for Trojan discovery nevertheless rests with Wolf and Palisa, who immediately identified the unusual motion of 588 Achilles. Despite Wolf’s extensive education in orbital mechanics, the association of Trojan asteroids with the elegant three-body solution of Lagrange seemed unknown to him. It was quickly pointed out by his Swedish colleague C. V. L. Charlier, who had just completed a textbook on celestial mechanics.

2a:T44a,

The instrument collection at the Royal Swedish Academy of Sciences houses a historically significant 10-foot achromatic refractor crafted by London instrument maker John Dollond. The telescope came into use at the Academy’s Observatory in Stockholm in 1761 and remained in service into the 1820s. This paper aims to add to the biography of this instrument, encompassing its six decades of active service and, after 150 years in storage, its transformation into an exhibition showpiece. The paper begins by introducing the telescope, its maker and the conflict involving Dollond and the Swedish mathematician and physicist Samuel Klingenstierna over the discovery of the achromatic lens. This dispute ultimately resulted in the telescope finding its way to the Stockholm Observatory. Subsequently, the paper delves into how Academy astronomer Pehr Wargentin perceived and utilized this state-of-the-art refractor, along with brief mentions of its use by his successors. The final section narrates how the telescope ended up in the permanent exhibition of the Stockholm Observatory Museum.