Related papers: Willem Janszoon Blaeu

Gy\"orgy Pa\'al, the Hungarian cosmologist died in 1992. This article was published twenty-five years later in the Hungarian Astronomical Association (HAA, MCSE in Hungarian) 2017 yearbook for his memory. After short introduction of the…

First proposed by Paczynski in 1986, microlensing has been instrumental in the search of compact dark matter as well as discovery and characterization of exoplanets. In this article, we provide a brief history of microlensing, especially on…

The Dutch scientist Christiaan Huygens refined Archimedes' celebrated geometrical computation of $\pi$ to its highest point. Yet the rich content of his beautiful treatise \emph{De circuli magnitudine inventa} (1654) has apparently never…

We examine connections between the mathematics behind methods of drawing geographical maps due, on the one hand to Marinos and Ptolemy (1st-2nd c. CE) and on the other hand to Delisle and Euler (18th century). A recent work by the first two…

Planetary nebulae are now well established as probes of galaxy dynamics and as standard candles in distance determinations. Motivated by the need to improve the efficiency of planetary nebulae searches and the speed with which their radial…

Precision premium, a concept in astrometry that was firstly presented by Pascu in 1994, initially means that the relative positional measurement of the Galilean satellites of Jupiter would be more accurate when their separations are small.…

Bernie Mills is remembered globally as an influential pioneer in the evolving field of radio astronomy. His contributions with the 'Mills Cross' at the CSIRO Division of Radiophysics and later at the University of Sydney's School of Physics…

At the end of the 17th century, the collection was established through the acquisition of Leiden instrumentmaker Musschenbroek's collection. Its aim was to demonstrate physical phenomena. Until the end of the 18th century, the collection…

In 1614, the German astronomer Simon Mayr published his claim to have discovered the satellites of Jupiter. Writing in the treatise Mundus Jovialis, Mayr made his assertion in a convoluted but unequivocal manner, earning the displeasure of…

The idea of dwarf and giants stars, but not the nomenclature, was first established by Eijnar Hertzsprung in 1905; his first diagrams in support appeared in 1911. In 1913 Henry Norris Russell could demonstrate the effect far more strikingly…

Since the expansion of the universe was first established by Edwin Hubble and Georges Lemaitre about a century ago, the Hubble constant H0 which measures its rate has been of great interest to astronomers. Besides being interesting in its…

This article focuses on the mathematical publications of Zygmunt Janiszewski (1888-1920), a major figure in Polish science at the beginning of the twentieth century. Serving in the Polish Legion between 1914 and 1920 in the struggle for…

Henri Deslandres initiated imaging spectroscopy of the solar atmosphere in 1892 at Paris observatory. He invented, concurrently with George Hale in Kenwood (USA) but quite independently, the spectroheliograph designed for monochromatic…

Johannes Hevelius's 1662 Mercurius in Sole Visus Gedani contains a table of magnitudes and apparent telescopic diameters of nineteen stars. The data conform to a simple model, suggesting that Hevelius produced what is essentially a table of…

Galileo Galilei believed that stars were distant suns whose sizes, measured via his telescope, were a direct indication of distance -- fainter stars (appearing smaller in the telescope) were farther away than brighter ones. Galileo argued…

Microlensing started with the seminal paper by Paczy\'nski in 1986, first with observations towards the Large Magellanic Cloud and the galactic bulge. Since then many other targets have been observed and new applications have been found. In…

Planck will be the first mission to map the entire cosmic microwave background (CMB) sky with mJy sensitivity and resolution better than 10'. The science enabled by such a mission spans many areas of astrophysics and cosmology. In…

In 1953 I heard of an experiment in 1925 by Bengt Str\"omgren where he observed transit times with the meridian circle at the Copenhagen University Observatory measuring the current in a photocell behind slits when a star was crossing. In…

In this brief article I review the history of astronomical photometry, touching on observations made by the ancient Chinese, Hipparchus and Ptolemy, the development of the concept (and definition) of magnitude, the endeavors of Argelander…

An intriguing reference to the existence of a self-portrait by Galileo Galilei is contained in the biography of the scientist by Thomas Salusbury dated ca. 1665, of which only one incomplete and inaccessible copy exists. Galileo grew up in…