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The Horometer instrument in Peter Apian's 1533 Instrument Buch is described and analyzed. This paper is illustrated by several examples of how to manipulate and set up the instrument using the Sun, the Moon and stars to determine time. The paper also contains an Appendix on the mathematics behind its construction. [ABSTRACT FROM AUTHOR]

We have determined the most probable date for the catalog of 34 stars that was used in the construction of a Latin astrolabe originally owned by the Dominican preacher friars and presently in the Musée des Arts Précieux Paul-Dupuy in Toulouse, France. To this end we digitized a photograph of the rete and the rule of the astrolabe, computed the equatorial coordinates of the ends of the 34 star pointers of the rete, and produced a list of 113 reference stars taken from several lists of stars on astrolabes. We then compared the coordinates of the ends of the pointers and those of the reference stars for dates between 1400 and 1700. The most probable date for this astrolabe is 1550. [ABSTRACT FROM AUTHOR]

In 1524, Petrus Apianus published two closely related works—one the Latin Cosmographicus liber, aimed at an educated audience of international readers, and the other, Ein kunstlich Instrument, a shorter, more practical book for those who could read German but had no Latin. Both books nevertheless make use of most of the same instruments, including Apianus' early volvelles. Most of these instruments also reappear in subsequent editions of Cosmographicus liber (or Cosmographia, a frequent alternative title). While the Cosmographicus liber has received much scholarly attention, Ein kunstlich Instrument has received very little. In this paper we (1) set the instruments of Ein kunstlich Instrument in the context of Apianus' earlier work, especially his lost Mappa mundi and the extant booklets (Declaratio and Isagoge) that explained it, (2) compare the German- and Latin-language books of 1524, (3) explain in detail those instruments that have not heretofore been adequately discussed, and (4) explore their later history. We also make available, in the on-line edition of the Journal, working virtual copies of Apianus' instruments from Ein kunstlich Instrument. [ABSTRACT FROM AUTHOR]

Astrophotonics is a burgeoning field that lies at the interface of photonics and modern astronomical instrumentation. Here we provide a pedagogical review of basic photonic functions that enable modern instruments, and give an overview of recent and future applications. Traditionally, optical fibres have been used in innovative ways to vastly increase the multiplex advantage of an astronomical instrument, e.g. the ability to observe hundreds or thousands of stars simultaneously. But modern instruments are using many new photonic functions, some emerging from the telecom industry, and others specific to the demands of adaptive optics systems on modern telescopes. As telescopes continue to increase in size, we look to a future where instruments exploit the properties of individual photons. In particular, we envisage telescopes and interferometers that build on international developments in quantum networks, the so-called quantum internet. With the aid of entangled photons and quantum logic gates, the new infrastructures seek to preserve the photonic state and timing of individual photons over a coherent network. [ABSTRACT FROM AUTHOR]

Scientific-grade cameras are frequently employed in industries such as spectral imaging technology, aircraft, medical detection, and astronomy, and are characterized by high precision, high quality, fast speed, and high sensitivity. Especially in the field of astronomy, obtaining information about faint light often requires long exposure with high-resolution cameras, which means that any external factors can cause the camera to become unstable and result in increased errors in the detection results. This paper aims to investigate the effect of displacement introduced by various vibration factors on the imaging of an astronomical camera during long exposure. The sources of vibration are divided into external vibration and internal vibration. External vibration mainly includes environmental vibration and resonance effects, while internal vibration mainly refers to the vibration caused by the force generated by the refrigeration module inside the camera during the working process of the camera. The cooling module is divided into water-cooled and air-cooled modes. Through the displacement and vibration experiments conducted on the camera, it is proven that the air-cooled mode will cause the camera to produce greater displacement changes relative to the water-cooled mode, leading to blurring of the imaging results and lowering the accuracy of astronomical detection. This paper compares the effects of displacement produced by two methods, fan cooling and water-circulation cooling, and proposes improvements to minimize the displacement variations in the camera and improve the imaging quality. This study provides a reference basis for the design of astronomical detection instruments and for determining the vibration source of cameras, which helps to promote the further development of astronomical detection. [ABSTRACT FROM AUTHOR]

The point-spread function (PSF) is a fundamental property of any astronomical instrument. In interferometers, differing array configurations combined with their uv coverage, and various weighting schemes can produce an irregular but deterministic PSF. As a result, the PSF is often deconvolved using CLEAN-style algorithms to improve image fidelity. In this paper, we revisit a significant effect that causes the flux densities measured with any interferometer to be systematically offset from the true values. Using a suite of carefully controlled simulations, we show that the systematic offset originates from a mismatch in the units of the image produced by these CLEAN-style algorithms. We illustrate that this systematic error can be significant, ranging from a few to tens of per cent. Accounting for this effect is important for current and future interferometric arrays, such as MeerKAT, LOFAR, and the SKA, whose core-dominated configuration naturally causes an irregular PSF. We show that this offset is independent of other systematics, and can worsen due to some factors such as the goodness of the fit to the PSF, the deconvolution depth, and the signal-to-noise ratio of the source. Finally, we present several methods that can reduce this effect to just a few per cent. [ABSTRACT FROM AUTHOR]

The article discusses a workshop titled "Tracking Astronomical Instruments Through Ottoman World and Beyond" that took place at Istanbul University. The workshop, organized by the Department of History of Science, aimed to explore the history of astronomy through hands-on activities with portable astronomical instruments. Led by distinguished scholars, the workshop included sessions on the history of astronomical instruments, the abjad number system, astrolabes, and paper instruments. Participants engaged actively and the workshop received support from various organizations. The article concludes that the workshop was a valuable and enriching experience that blended theoretical knowledge with practical engagement, contributing to participants' understanding of astronomical history and setting a precedent for future interdisciplinary workshops. [Extracted from the article]

Geometric optical distortion is a significant contributor to the astrometric error budget in large telescopes using adaptive optics. To increase astrometric precision, optical distortion calibration is necessary. We investigate using smartphone Organic Light-Emitting Diode (OLED) screens as astrometric calibrators. Smartphones are low-cost, have stable illumination, and can be quickly reconfigured to probe different spatial frequencies of an optical system's geometric distortion. In this work, we characterize the astrometric accuracy of a Samsung S20 smartphone, with a view towards providing large format, flexible astrometric calibrators for the next generation of astronomical instruments. We find the placement error of the pixels to be 189 nm ± 15 nm Root Mean Square (RMS). At this level of error, milliarcsecond astrometric accuracy can be obtained on modern astronomical instruments. [ABSTRACT FROM AUTHOR]

Characterizing the properties (e.g., effective dielectric constant εeff, attenuation constant α, and characteristic impedance Z0) of terahertz (THz) superconducting transmission lines is of particular interest in designing on-chip integrated THz bandpass filters, which are a critical component for THz astronomical instruments, such as multi-color camera and broadband imaging spectrometers. Here, we propose a novel method for the characterization of three parameters (εeff, α, and Z0) of THz superconducting transmission lines. This method measures the ratio of the THz signal powers through two different-length branches of the superconducting transmission line to be measured. In addition, only one measurement is required for an all-in-one device chip, including an antenna, a half-power divider, the superconducting transmission line to be measured, and two detectors. The key point is that the superconducting transmission line to be measured is impedance-mismatched with the two integrated detectors. The method is validated through simulation and measurement for superconducting coplanar waveguide transmission lines around 400 GHz. [ABSTRACT FROM AUTHOR]

MOONS is a multi‐object spectrograph that will be installed at the Nasmyth focus of the VLT ESO Telescopes in Chile. The instrument has the capacity to deploy approximately 1000 fibers over a field of view of 500 square arcminutes, with a total wavelength coverage of from 0.6 to 1.8 μ$$ \mu $$m, offering both low‐ and medium‐resolution modes. The high demand for fast and large optics in all spectral channels prompted the use of similar f/0.95$$ f/0.95 $$ Schmidt cameras. As a result, the Detector Unit (DU) must be located within the optical beam and its footprint must be minimized to reduce vignetting. The instrument consists of four H4RG‐15um pixel detectors and two fully depleted LBNL CCDs. This article provides a comprehensive description of the detector systems, focusing particularly on the H4RG‐15, including a brief overview of the newly developed cryogenic pre‐amplifier for 64‐output operation, and a detailed discussion of the woven cable technology used for signal routing. Some results of the characterization of three H4RG detectors are presented, with a focus on crosstalk and buffer output performance. The use of the buffer output for the H4RG results in a glow‐per‐read observed at the bottom of the detectors. This article also describes the trade‐offs and alternatives used to optimize detector performance in this situation. [ABSTRACT FROM AUTHOR]

The paper describes an improved spectrograph of the Cassegrain focus of the 2-meter ShAO reflector using a CCD camera. The classic Universal Astro Grid Spectrograph (UAGS) was adapted to use the Andor CCD camera to obtain spectra of objects with low brightness in the range of 3600–8000 Å. A spectrograph with a diffraction grating of 651 lines/mm makes it possible to obtain the spectra of stars on the 2‑m ShAO telescope up to 18 mag with the resolution R = 1200, with a signal-to-noise ratio of about 50 for half an hour of exposure. The maximum allowable resolution is R = 3400 with binning 1 × 1. The complex can be used for observations of various types of transient objects, variable stars, and extragalactic objects. [ABSTRACT FROM AUTHOR]

The first photographs taken at the Cape of Good Hope (and therefore South Africa) date from 1843 and were due to Charles Piazzi Smyth, Chief Assistant at the Royal Observatory, Cape. His surviving positives and negatives are gathered here with descriptions of their subjects. They are mainly of the Royal Observatory, Cape of Good Hope, of a Magnetic Observatory on the same site that no longer exists, and of various buildings in Cape Town. However, they also include the first photographic portraits made at the Cape and images of two astronomical instruments. [ABSTRACT FROM AUTHOR]

This paper presents a new instrument setup at the Bucharest Observatory of the Astronomical Institute of the Romanian Academy, as well as preliminary results using this setup. It consists of records of VLF (very low frequency) perturbations using a superSID instrument. During March and December 2022 various mounts and settings tests have been performed. Starting October we obtained satisfactory data. We report on detecting the signature of moderate to intense solar flares (M and X-class). In this configuration, the C-class solar flares are less distinguishable from the background noise. [ABSTRACT FROM AUTHOR]

In this article we describe the developement of an insulated box with a thermostat controller to protect the sensitive Baader Solar Spectrum H alpha filter in the low temperatures of winter. Our goal is to facilitate daily solar synoptic observations in all seasons. [ABSTRACT FROM AUTHOR]

We present an estimation and analysis of Near Infrared (NIR) background for the astronomical site at Mount Abu. Mount Abu Observatory is situated at Gurushikhar, Rajasthan, India, operated by the Physical Research Laboratory. Data obtained from the NIR observations of various sources using the Near Infrared Camera/Spectrograph (NICS) on the 1.2-m telescope are used to derive the NIR background estimates. We notice seasonal variations in these values, with the summer months showing brighter background compared to the winter. We also present a comparison of synthetic atmospheric transmission at Mount Abu with other Indian observatories at various altitudes. We identify the plausible contributors to the NIR background in our observations and discuss the potential ones that can contribute to the noticed seasonal variations. Overall, we found that the NIR background does not show any systematic variation over the period of observations from 2010 to 2019. The results reported here are specific to the NICS instrument on the 1.2-m telescope. [ABSTRACT FROM AUTHOR]

This paper explores the use of new scientific techniques to examine collections of historic scientific apparatus and other technological artefacts. One project under discussion uses interferometry to examine the history of lens development, while another uses X-ray fluorescence to discover the kinds of materials used to make early mathematical and astronomical instruments. These methods lead to surprising findings: instruments turn out to be fake, and lens makers turn out to have been adept at solving the riddle of aperture. Although exciting, in some ways this is neither novel nor particularly unusual. After all, lab techniques have been used in art and archaeological collections for a very long time. In fact, scientific instruments themselves have been examined in this way since at least the 1950s. What, then, is special about the use of new instruments to examine old instruments? We argue that the answer has less to do with measuring historical innovation or establishing priority, and more to do with networks of craft know-how that, typically, have left no other historical traces than those embodied in surviving instruments themselves. We show, in particular, how collections of objects can be mobilised within wider histories of knowledge, placing instruments within a dynamic interplay of craft knowledge, expertise, labour, commerce, and material exchange, over the longue durée. Finally, we suggest that these kinds of lab analyses can be given an extra dimension through the use of computational modelling, and we introduce the "Tools of Knowledge" project, which is designed to bring together XRF with techniques from the digital humanities, in order to tell a new story about the development of scientific instruments from the 16th to the 20th century. [ABSTRACT FROM AUTHOR]

Gravitational lensing is a topic of great application value in the field of astronomy. The properties and research methods of gravitational lensing are closely related to the geometric and relativistic characteristics of the background universe. This review focuses on the theoretical research and application of strong lenses and weak lenses. We first introduce the basic principles of gravitational lensing, focusing on the geometric basis of geometric lensing, the representation of deflection angles, and the curvature relationship in different geometric spaces. In addition, we summarize the wide range of applications of gravitational lensing, including the application of strong gravitational lensing in Schwarzschild black holes, time delay, the cosmic shearing based on weak lensing, the applications in signal extraction, dark matter, and dark energy. In astronomy, through the use of advanced astronomical instruments and computers, analyzing gravitational lensing effects to understand the structure of galaxies in the universe is an important topic at present. It is foreseeable that gravitational lensing will continue to play an important role in the study of cosmology and will enrich our understanding of the universe. [ABSTRACT FROM AUTHOR]

The eighth-century Latin manuscript Milan, Veneranda Biblioteca Ambrosiana, L 99 Sup. contains fifteen palimpsest leaves previously used for three Greek scientific texts: a text of unknown authorship on mathematical mechanics and catoptrics, known as the Fragmentum Mathematicum Bobiense (three leaves), Ptolemy's Analemma (six leaves), and an astronomical text that has hitherto remained unidentified and almost entirely unread (six leaves). We report here on the current state of our research on this last text, based on multispectral images. The text, incompletely preserved, is a treatise on the construction and uses of a nine-ringed armillary instrument, identifiable as the "meteoroscope" invented by Ptolemy and known to us from passages in Ptolemy's Geography and in writings of Pappus and Proclus. We further argue that the author of our text was Ptolemy himself. [ABSTRACT FROM AUTHOR]

In this article, we report the discovery of a new type of astronomical almanac by Joseph Ibn Waqār (Córdoba, fourteenth century) that begins at second station for each of the planets and may have been intended to serve as a template for planetary positions beginning at any dated second station. For background, we discuss the Ptolemaic tradition of treating stations and retrograde motions as well as two tables in Arabic zijes for the anomalistic cycles of the planets in which the planets stay at first and second stations for a period of time (in contrast to the Ptolemaic tradition). Finally, we consider some medieval astrological texts where stations or retrograde motions are invoked. [ABSTRACT FROM AUTHOR]

"Planetarien: Wunder der Technik—Techniken des Wunderns" by Helen Ahner is a book that explores the history and significance of planetariums as places of popular science education and entertainment. The author focuses on the period between 1925 and 1930 and examines case studies in Munich, Jena, Vienna, and Hamburg. Ahner argues that the planetarium experience was associated with wonder and amazement, and that the physical experience of the audience was more important than the content of the shows. The book also discusses the planetarium's role in modernity and its ability to condense central themes of the time. [Extracted from the article]

This work deals with a new theoretical method proposed with the intent of improving the quality of astronomical polarimetric data. The theoretical method is applied to one of the simplest possible birefringent type polarizer device constructs, being a hybrid measurement procedure between the fixed position angles and the continuous rotation records of the modulator (in our case, the quarter-wave plate) methods. It can be suitable for some astronomical applications in Planetary Science and Stellar Astrophysics, as their polarimetric parameters (polarization degree, polarization angle and Stokes parameters) have relatively stable values, allowing for the iterative proposed procedure. The validity of the procedure is expected to be practically proven by comparing the quality of the polarization parameters obtained with it, on the proposed instrument, with the results obtained with a similar standardized instrument on the market. [ABSTRACT FROM AUTHOR]

The Perseverance rover landed in Jezero crater, Mars, in February 2021. We used the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument to perform deep-ultraviolet Raman and fluorescence spectroscopy of three rocks within the crater. We identify evidence for two distinct ancient aqueous environments at different times. Reactions with liquid water formed carbonates in an olivine-rich igneous rock. A sulfate-perchlorate mixture is present in the rocks, which probably formed by later modifications of the rocks by brine. Fluorescence signatures consistent with aromatic organic compounds occur throughout these rocks and are preserved in minerals related to both aqueous environments. [ABSTRACT FROM AUTHOR]

This essay examines the problems associated with the installation of a precision instrument at the National Astronomical Observatory of Chile, starting before its construction and following the process through its installation to its later useful life. Between 1908 and 1913, the director of the observatory, Friedrich W. Ristenpart, corresponded with the German manufacturer, A. Repsold & Söhne in Hamburg, trying to identify the critical points pertinent to the installation of the instrument in Chile. These communications reveal how the installation of the instrument required the stabilization of local knowledge (location, adjustment, calibration, and staging) that would allow the data it obtained to be universally validated. This correspondence between user and manufacturer also reveals that the phenomenon of the mobility of instruments implies much more than simply transporting something from one place to another: there is no movement without some type of coordination between the extraction of an object from a certain place and context and its insertion into a new place and set of relationships. [ABSTRACT FROM AUTHOR]

The period of the last third of 19th century was beneficial to a boom of observatories run by amateur astronomers. One of them was built in Hurbanovo. It is well known that place names have changed throughout history; sometimes more than one was used at the same time, and it often depended on the language in which the historical documents were written. These peculiarities can easily confuse the modern reader. For the sake of clarity, we have decided to use modern official geographical names. Even in Anglophone historiographical literature, modern names are usually used in the first place instead of historical ones. All other historical forms of place names are mentioned in parentheses when they first appear (first in Hungarian, then in German). Several names or variations of those names may be discovered in historical records pertaining to Hurbanovo, e.g.: Stará Ďala (in Slovak), Ó-Gyalla, O Gyalla, Ógyalla, Ogyalla, Ó Gyalla, Ó Gyala, Ó-Gyala, Ó Gyála (in Hungarian), Altdala (in German). The town was named Hurbanovo in 1948. (Slovakia) in 1871 by a local nobleman Nicolaus de Konkoly. The paper is divided into two main parts. The first part is focused on the development of instrumentation and domes of the observatory. The second one is focused on various kinds of astronomical and astrophysical observations performed by the observatory staff from the beginning of the observatory until the dissolution of the Austro-Hungarian Empire in 1918. [ABSTRACT FROM AUTHOR]

A historical research study devoted to the elucidation of the historical facts about the activity of the Kharkiv Astronomical Observatory during the German–Soviet War is carried out. The astronomical community of Kharkiv suffered heavy losses: Professors O.I. Razdol'skii, M.S. Savron, and S.M. Semiletov, Researcher G.L. Strashnii, Yu.M. Fadeev, and V.O. Balanskii, and calculation specialist L.M. Kostirya died; young representatives of the Kharkiv astronomical community M. Azbel', F. Berezovskii, I. Tymoshenko, and O. Ubiivovk gave their lives in the battle with the enemy. During warfare, many observatory buildings, together with astronomical instruments and devices, were seriously damaged. The peculiarities of observatory operation during the studied period have been documented, and the biographical data of most of the employees of the Kharkiv Astronomical Observatory during the Nazi occupation of the city in 1941–1943 have been clarified. The stages of restoration of the observatory after the liberation of Kharkiv from the invaders were considered. [ABSTRACT FROM AUTHOR]

Disputes over whether the Scientific Revolution contributed to the Industrial Revolution begin with the common assumption that natural philosophers and artisans formed distinct groups. In reality, these groups merged together through a diverse group of applied mathematics teachers, textbook writers, and instrument makers catering to a market ranging from navigators and surveyors to bookkeepers. Besides its direct economic contribution in diffusing useful numerical skills, this "practical mathematics" facilitated later industrialization in two ways. First, a large supply of instrument and watch makers provided Britain with a pool of versatile, mechanically skilled labor to build the increasingly complicated machinery of the late eighteenth century. Second, the less well-known but equally revolutionary innovations in machine tools—which, contrary to the Habbakuk thesis, occurred largely in Britain during the 1820s and 1830s to mass-produce interchangeable parts for iron textile machinery—drew on a technology of exact measurement developed for navigational and astronomical instruments. [ABSTRACT FROM AUTHOR]

The torquetum was a complex astronomical instrument whose construction is known thanks to certain descriptions, iconography and few extant artefacts. It was used in pre-telescopic astronomy from at least the 13th century. However, the usefulness of the torquetum as an observing instrument remains unknown. It is my intention to introduce a preliminary analysis of the merits and limitations of the torquetum in determining the coordinates of celestial bodies. For this purpose I shall refer to (1) written sources that contain descriptions of the construction of the instrument and its use; (2) the results of an examination of the torquetum constructed by Hans Dorn of Vienna (c.1487) and conserved in the Jagiellonian University Museum in Cracow; (3) elements of a theory of the instrument, which allow us to trace down instrumental errors, both systematic and accidental; (4) the only substantial and extant set of observations made with the torquetum, that is, a catalogue of 58 stars, compiled in Kassel in the years 1560–63. [ABSTRACT FROM AUTHOR]

An analysis is presented of the scientific research accomplished by Ukrainian astronomer Mykola Evdokymov, a specialist in the field of astrometry. The astronomer's main works, carried out using a Repsold meridian circle, are dedicated to determining stellar parallaxes, the positions of zodiacal and faint circumpolar stars, and the positions of large planets. At Kharkiv Astronomical Observatory, Evdokymov conducted systematic observations of the following objects and phenomena: solar and lunar eclipses, including as a member of the observatory's expeditions during the total solar eclipses of 1914 and 1936; comets (Halley, Delavan, Stearns, Pons–Winnecke); and meteor showers. He participated in determining the positions of reference stars for the asteroid (433) Eros. He conducted systematic studies of the meridian circle, developed new astronomical instruments, organized the functioning of a time service at the observatory, and carried out the determination of star declinations by measuring the sums and differences of the zenith distances of star pairs by the Sanders–Raymond method (using a meridian circle and a transit instrument). [ABSTRACT FROM AUTHOR]

The O9.7 V star HD 54879 is currently the only massive magnetic star whose magnetic field geometry and rotation period are not constrained. Over the last 3 yr, we gathered additional observations of this star, obtained using various instruments at several astronomical facilities, with the aim to constrain the rotation period and the magnetic field geometry. The new data include the first full Stokes vector observations with the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI), installed at the Large Binocular Telescope. The acquired spectropolarimetric observations show a very slow magnetic field variability related to the extremely slow rotation of HD 54879, which is also indicated in a dynamical spectrum, displaying variability of the Hα line. The most intriguing result of our study is the discovery of differences in longitudinal magnetic field strengths measured using different least-squares deconvolution (LSD) masks containing lines belonging to different elements. It is the first time that such a differential analysis of the field strength in dependence of the used lines is carried out for a magnetic O-type star. Since the LSD Stokes  I profiles of the studied O, Si, and He line masks remain stable over all observing epochs, we conclude that the detection of different field strengths using lines belonging to these elements is related to the different formation depths, with the He lines formed much higher in the stellar atmosphere compared to the silicon and the oxygen lines, and non-local thermodynamic equilibrium (NLTE) effects. Our numerical magnetospherical model suggests the presence of enhanced gas density that fills the volume inside the field lines close to the star. [ABSTRACT FROM AUTHOR]

Equally, surviving instruments complement the literature of the astrolabe and supply basic information about their functions and makers. In the arrangement of the text overall, however, they have made a major change in abandoning the strict alphabetical order by names of makers adopted by Brieux and Maddison for one arranged by "types" of instruments identified mainly by their place of origin, sorted into centuries and then, within those, presented in chronological order. The authors seek to inventory all the known makers of astrolabes and related astronomical instruments and to list all their known works. [Extracted from the article]

In the article "New books & media" from Physics Today, two books are highlighted that are relevant to the upcoming total solar eclipse in April 2024. The first book, "America's First Eclipse Chasers" by Thomas Hockey, explores the historical significance of the first total solar eclipse to occur over the continental US in 1869. Hockey argues that this event marked the first large-scale astronomical expeditions in the US and the first use of photography to capture scientifically useful images of the Sun. The second book, "Totality: The Great North American Eclipse of 2024" by Mark Littmann and Fred Espenak, serves as a guide for viewing the upcoming eclipse and provides information on different types of eclipses, the science behind them, and guidelines for safely photographing the phenomenon. The article also mentions the Apple TV+ series "Monarch: Legacy of Monsters," which explores the role of scientists in addressing problems, drawing parallels to debates on climate change. [Extracted from the article]

Nevertheless, Lawrence-Mathers pays much attention to meteorology in the Peripatetic sense, as the more general subject in which weather forecasting can be encompassed. A short-lived periodical on the history of weather forecasting was founded by G. Hellmann in 1914, but it is only in recent years that significant attention has been paid to weather forecasting in pre-modern times. [Extracted from the article]

This article is devoted to a thirteenth-century Latin text on how to construct, set up, and use a version of the so-called armillary instrument (instrumentum armillarum), which was first described in Ptolemy's Almagest as a tool for measuring ecliptic coordinates. Written in 1264 by Guillaume des Moustiers, bishop of Laon, this hitherto unstudied Tractatus super armillas survives in a single manuscript, where it is accompanied by a copious set of glosses. The text and its glosses jointly offer an unusually detailed account of the instrument's material aspects and methods of assembly. In addition, they reflect a keen awareness of the potential sources of error that may arise in the context of astronomical observation, while making suggestions on how these errors may be minimized or avoided. The Tractatus super armillas accordingly is a valuable source on the observational side of medieval European astronomy, which has often been minimized in modern historical accounts. [ABSTRACT FROM AUTHOR]

The feasibility of expanding the evaluation parameters was discussed when selecting the "Karadag" test site for the installation of millimeter-wave antennas based on the following: a comparative analysis of the data on the integral atmosphere moisture content in the time interval from August 2019 to January 2020 for the NIRFI NNSU "Karadag" test site, three IAA RAS test sites ("Zelenchukskaya", "Svetloe", and "Badary") and the construction site of the 70-m radio telescope on the "Suffa" plateau (Uzbekistan) (average values for 1981–1991). This is due to the absence of places in the Russian Federation territory with consistently good atmospheric transparency in the millimeter-wave range, comparable to the Chahnantor plateau in Chile. Using the monthly average values of the integral moisture content as the main criterion for choosing a test site, one should consider both the characteristic of the wind rose at the "Karadag" test site and a more detailed daily and intraday distribution of moisture content. At the "Karadag" test site, even in summer, high transparency of the atmosphere periodically appears. Integral moisture content decreases to levels comparable to this parameter in the Suffa mountain area. The results obtained make it possible to correct the current principles for the placement of astronomical instruments and space communication systems of the millimeter and submillimeter-wave ranges in the territory of the Russian Federation. [ABSTRACT FROM AUTHOR]

Argument: The Greenwich Prime Meridian is one of the iconic features of the Royal Museums Greenwich. Visitors to the Museum even queue up to pose with one leg on either side of the Line. Yet, the Airy Transit Circle, the instrument that defined the meridian, is almost always excluded from these photographs. This paper examines how the instrument has become hidden in plain sight within the stories of Greenwich Time and Greenwich Meridian, as well as within the public imagination, by providing an analysis of the instrument's transformation from a working astronomical instrument to a museum object. The paper highlights the gradual decoupling of the instrument from narratives of Time and Longitude, which resulted in the Line's popularity overshadowing the instrument that defined it. By doing so, the paper aims at showing the symbiotic relationship between the materiality of the instrument and the meridian line that it defined. Approaching the instrument through the lenses of object biographies, the paper raises the question of whether the life of the instrument came to an end once operations with it were terminated. The analysis of the Transit Circle's life reveals that it reached its end multiple times, which shifts the emphasis away from a single and ultimate end of scientific objects to a process of gradual downfall, during which they can "end" several times. In addition, through the object biography approach, the Transit Circle no longer appears as a dead object reaching an afterlife within a museum setting. Instead, the approach demonstrates that, though the instrument can still be restored to an operational order, doubts about its accuracy, and its relevancy to today's astronomical methods, have led the instrument to be considered obsolete, transforming it into a museum object on display. [ABSTRACT FROM AUTHOR]

We present a new way to mitigate focal-ratio degradation (FRD) when using optical fibres to transport multimode light. Our approach exploits a custom multicore fibre (MCF) with six dissimilar cores that are single-mode at ∼1550 nm wavelength and minimally coupled over 7 m. We fabricated adiabatic mode-selective photonic lanterns (PLs) at each end of the MCF to create a fibre link with multimode ports, the PLs coupling each spatial mode of the multimode ports to a specific core of the MCF and vice versa. The PL-MCF-PL link exhibits superior FRD behaviour compared to a conventional multimode fibre that also supports six modes, because it inhibits the transfer of light from lower order modes to higher order modes. These results open up a potential powerful new approach to mitigate FRD in multimode fibre links, with particular applications in astronomical instruments. [ABSTRACT FROM AUTHOR]

For a millennium, between the 9th and 19th centuries, astronomical instrumentation had a vital role in scientific endeavour in the Islamic world. Different types of instruments, various engravings and markings, the makers’ signatures and dedications, construction dates, and artistic features provide ample evidence for assessing the level, transition, and transmission of knowledge in the period. In this manner, celestial globes are historically significant but undeservingly neglected instruments. They are the second largest group of instruments, after astrolabes, illustrative of the history of Islamic astronomy with more than two hundred extant globes. Despite its popularity throughout history, globe making procedures remain somewhat obscure. This paper presents a brief overview of the globe making tradition in the Islamic world. It deals with two main sources of information: manuals on the construction/use of globes and the extant globes. In this regard, the 10th century astronomer ʿAbd al-Raḥmān al-Ṣūfī’s (d. 376/986) Book of the Constellations (Kitāb Ṣuwar al-kawākib al-thābita) and Abū ʿAlī al-Ḥasan al-Marrākushī’s (second half of the 7th/13th century) From A to Z: A Compendium of Timekeeping (Jāmīʿ al-mabādī wa-l-ghāyāt fī ʿilm al-mīqāt) are highlighted as potentially the sources that were used by instrument makers. The paper raises questions regarding the influence of these works on the instrument makers and consequently on globes. The discussion on this wide-range topic, however, is limited to only a few examples as a pointer for future studies. [ABSTRACT FROM AUTHOR]

Starlight corrupted by atmospheric turbulence cannot couple efficiently into astronomical instruments based on integrated optics as they require light of high spatial coherence to couple into their single-mode waveguides. Low-order adaptive optics in combination with photonic lanterns offer a practical approach to achieve efficient coupling into multiplexed astrophotonic devices. We investigate, aided by simulations and an experimental testbed, the trade-off between the degrees of freedom of the adaptive optics system and those of the input waveguide of an integrated optic component leading to a cost-effective hybrid system that achieves a signal-to-noise ratio higher than a standalone device fed by a single-mode fibre. [ABSTRACT FROM AUTHOR]

Enabling efficient injection of light into single-mode fibres (SMFs) is a key requirement in realizing diffraction-limited astronomical spectroscopy on ground-based telescopes. SMF-fed spectrographs, facilitated by the use of adaptive optics (AO), offer distinct advantages over comparable seeing-limited designs, including higher spectral resolution within a compact and stable instrument volume, and a telescope independent spectrograph design. iLocater is an extremely precise radial velocity (EPRV) spectrograph being built for the Large Binocular Telescope (LBT). We have designed and built the front-end fibre injection system, or acquisition camera, for the SX (left) primary mirror of the LBT. The instrument was installed in 2019 and underwent on-sky commissioning and performance assessment. In this paper, we present the instrument requirements, acquisition camera design, as well as results from first-light measurements. Broad-band SMF coupling in excess of 35 per cent (absolute) in the near-infrared (0.97–1.31  |${\mu {\rm m}}$|⁠) was achieved across a range of target magnitudes, spectral types, and observing conditions. Successful demonstration of on-sky performance represents both a major milestone in the development of iLocater and in making efficient ground-based SMF-fed astronomical instruments a reality. [ABSTRACT FROM AUTHOR]

The evolution undergone by the concept of observation in contemporary astronomy has generated new scientific conceptions about the observable universe, as well as different reflective ways of conceiving it. Technological advances in recent astronomical instruments have led to new and more sophisticated observational practices within this discipline. As they have become more complex, historical approaches are crucial to teach philosophy of astronomy. In this article, an attempt will be made to create an appropriate context for the teaching of philosophical problematics of science in astronomical academic settings. In particular, taking into account the metamorphoses suffered by the concept of observation in current astronomy and, the point of view from the philosophy of scientific practices, it is intended to show how that concept has been losing its ability to reflect subtle aspects of epistemological relevance. One of the aims here is to encourage members of the astronomical community to reflect on such problems. Through a historical description along the last decades of astronomy, it will be shown how those technoscientific changes have influenced on the conception of observation itself. This way philosophers and astronomers may generate innovative strategies while teaching philosophical contents. This may help astronomers to rethink the way they carry out their own investigations. [ABSTRACT FROM AUTHOR]

The Airy Transit Circle of the Royal Observatory, Greenwich is one of the most important instruments in the history of astronomy, navigation and time distribution. However, there has been very little research done on the history of the instrument. This article examines how the purchase of the object glass for the Airy Transit Circle involved active negotiations between George Biddell Airy and three different opticians: Georg Merz, Noel Paymal Lerebours, and William Simms. The article also shows the involvement of John Herschel and Richard Sheepshanks in Airy's decision making process. By highlighting the presence of these individuals, the article shows how Airy's trust and distrust in different instrument makers influenced his choice of supplier for the object glass of the Airy Transit Circle. [ABSTRACT FROM AUTHOR]

The processing of raw data from modern astronomical instruments is often carried out nowadays using dedicated software, known as pipelines, largely run in automated operation. In this paper we describe the data reduction pipeline of the Multi Unit Spectroscopic Explorer (MUSE) integral field spectrograph operated at the ESO Paranal Observatory. This spectrograph is a complex machine: it records data of 1152 separate spatial elements on detectors in its 24 integral field units. Efficiently handling such data requires sophisticated software with a high degree of automation and parallelization. We describe the algorithms of all processing steps that operate on calibrations and science data in detail, and explain how the raw science data is transformed into calibrated datacubes. We finally check the quality of selected procedures and output data products, and demonstrate that the pipeline provides datacubes ready for scientific analysis. [ABSTRACT FROM AUTHOR]

The period between 1890 and 1930 saw a flowering of astronomical endeavour in Queensland and also a drama that ended in the demise of the Brisbane Astronomical Society. One of those involved was Dudley Eglinton, a populariser of astronomy who organised the purchase of a 6-inch refracting telescope and established the Brisbane Astronomical Society in 1896. The other was James Park Thomson who founded the Queensland Branch of the Geographical Society of Australasia (later the Royal Geographical Society of Australasia). His main interest was in geography, but he was also a competent observational astronomer. After the demise of the Brisbane Astronomical Society, Eglinton formed a new Society, the Queensland Popular Science and Art Society, and raised funds to buy a new telescope, but he soon became blind. The new Society appears to have quickly foundered, but within a few years the Astronomical Society of Queensland (1927–1978) was formed as a successor to the Brisbane Astronomical Society and Eglinton was elected a Vice-President. Thomson appears to have played no part in this new Society. [ABSTRACT FROM AUTHOR]

The observatory of Ulugh Beg, erected in Samarqand in the 1420s, represents the culmination in the development of astronomical observatories in the Islamic world. After its rediscovery and excavation in the early twentieth century there have been several attempts to reconstruct its appearance and explain how it worked in detail, based on archaeological finds and the analysis of relevant manuscripts. A new look at illustrated copies of an important manuscript provides new, hitherto unmentioned details to the understanding of this instrument. Based on previous reports, we have created a virtual reconstruction of the observatory and the new version of the instrument, from which we have gained new insights. [ABSTRACT FROM AUTHOR]

The flexible interchange transport system (FITS) file format has become the de facto standard for sharing, analyzing, and archiving astronomical data over the last four decades. FITS was adopted by astronomers in the early 1980s to overcome incompatibilities between operating systems. On the back of FITS' success, astronomical data became both backward compatible and easily shareable. However, new advances in the astronomical instrumentation, computational technologies, and analytic techniques have resulted in new data that do not work well within the traditional FITS format. Tensions have arisen between the desire to update the format to meet new analytic challenges and adherence to the original edict for the FITS file format to be backward compatible. We examine three inflection points in the governance of FITS: first, initial development and success, second, widespread acceptance and governance by the working group, and third, the challenges to FITS in a new era of increasing data and computational complexity within astronomy. [ABSTRACT FROM AUTHOR]