scholarly journals Curved detectors developments and characterization: application to astronomical instruments

2018 ◽  
Author(s):  
Simona Lombardo ◽  
Wilfried Jahn ◽  
Thibault Behaghel ◽  
Emmanuel Hugot ◽  
Eduard Muslimov ◽  
...  
Keyword(s):  
Astronomical Instruments

General

2017 ◽  
Vol 64 (2) ◽  
pp. 220-238
Author(s):  
Ivana Petrovic ◽  
Andrej Petrovic
Keyword(s):  
The Sun ◽  
Creation Myths ◽  
The Third ◽  
Greco Roman ◽  
Astronomical Instruments ◽  
Music Of The Spheres ◽  
Desert Island ◽  
Complete Translation

If you still haven't chosen a book to take with to the desert island, I have a suggestion: L'encyclopédie du ciel. At 1,202 pages, it will keep you occupied day and night: what you read as text by day will help you read by night in the sky. This wonderful and extremely useful book is as difficult to classify as it is to put down. Essentially, it is a compendium of Greco-Roman discourse on the stars and planets, divided into three parts. The first (‘Les images: histoire et mythologie: voir et raconter’) is about the constellations and the planets. It opens with a catalogue in which each constellation is illustrated, explained, and accompanied with appropriate quotations from Eratosthenes’ Catasterismoi and Hyginus’ Astronomica. There follow essays about the names of the constellations, on the Sun, Moon, and the planets, and one on Greek and Roman creation myths. All are accompanied by long passages of appropriate Greek and Latin texts in translation. The second part of the book (‘Les lois: l'astronomie: observer et calculer’) is about the ancient attempts to make sense of and explain the stars and planets as a system, about calendars, and about ancient astronomical instruments and objects. This part of the book also contains a complete translation of Hipparchus’ Commentary on the Phaenomena of Eudoxus and Aratus. It closes with an account of Greek star catalogues. The third part of the book is concerned with various attempts to interpret the celestial phenomena (‘Les messages: signes et influence: interpréter et prédire’). It includes, but is not restricted to, astrology; philosophical ideas are also discussed, such as astral apotheosis, the ascent of the soul through the sky, and the music of the spheres. There is a dictionary of astronomical and astrological terms and a dictionary of ancient astronomers and authors dealing with astronomy. The book closes with parallel star catalogues of Eratosthenes, Hipparchus, and Ptolemy.

scholarly journals VI. Appendix to the preceding paper on the changes which appear to have taken place in the declination of some of the fixed stars

1823 ◽  
Vol 113 ◽  
pp. 39-52
Keyword(s):  
Preceding Paper ◽  
Direct Proportion ◽  
Astronomical Instruments ◽  
Actual Observation ◽  
The Subject ◽  
The Right ◽  
Right Ascension

The observations which have been made during the last summer, confirm in a very decided manner the results which formed the subject of my last communication; in which I laid before the Society the nature of the differences that exist between the computed places of the principal Stars of the Greenwich Catalogue, and those deduced from actual observation. It is not my present intention to offer any explana­tion of the cause of these phenomena, although many obvious conjectures present themselves, the value of which it will require perhaps many years to determine. It is now my principal object to consider the force of that explanation of the differences in question, which will most readily occur to every astronomer, namely, that the whole may arise either from error committed by the observer, or from defect in the instruments of observation: this objection being the more weighty from the circumstance, that the observations of three distant periods are employed, and that an error in those of either period (but particularly of the two latter) would ma­terially affect the result now under consideration. I believe that every person, in proportion to his experience in the use of astronomical instruments, (even of the most unexceptionable construction), will be cautious in admitting the accuracy of any results, with whatever care the observations may have been made, which appear to militate against any received theory of astronomy; and I shall have occasion myself to show, from the great discordances between instru­ments of the highest reputation, that this distrust is but too well founded. More particularly ought our suspicion to be excited, when such anomalies are found to exist, as bear some direct proportion to the zenith distances of the stars observed. In all such cases we should never hesitate, I think, to ascribe the anomalies to defective observation. If therefore in the present instance, any part of the discordances in question can be shown to depend on polar or zenith distances, I shall willingly admit, as to such part of them at least, that they are no otherwise of importance, than as affording data for leading to the detection of some hitherto undiscovered errors. The anomalies, however, that have led me on to this enquiry, and to which alone I attach any importance, are found to de­pend rather on the right ascensions, than on the declinations of the stars. Accordingly I found, while collecting observa­tions to form a catalogue for the present period, that I could more nearly predict the deviation of a star from its computed place, by knowing its right ascension, than its declination. Now it is not easy to conceive in what way the error of an instrument for measuring declination, fixed in the meridian, can be occasioned by any circumstance depending on the right ascension of a star to be observed.

scholarly journals Final design and on-sky testing of the iLocater SX acquisition camera: broad-band single-mode fibre coupling

2020 ◽  
Vol 501 (2) ◽  
pp. 2250-2267
Author(s):  
J Crass ◽  
A Bechter ◽  
B Sands ◽  
D King ◽  
R Ketterer ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Broad Band ◽  
Single Mode ◽  
Injection System ◽  
Single Mode Fibre ◽  
Astronomical Instruments ◽  
Final Design ◽  
Camera Design ◽  
And Performance

ABSTRACT 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.

Astronomical Instruments and Techniques

1987 ◽  
pp. 143-200
Author(s):  
S. Böhme ◽  
U. Esser ◽  
H. Hefele ◽  
I. Heinrich ◽  
W. Hofmann ◽  
...  
Keyword(s):  
Astronomical Instruments ◽  
Instruments And Techniques

scholarly journals 4. On the Dynamical Theory of Dispersion

1884 ◽  
Vol 12 ◽  
pp. 128-128
Author(s):  
William Thomson
Keyword(s):  
Dynamical Theory ◽  
Scientific Instruments ◽  
Astronomical Instruments

Professor Tait laid upon the table a series of Photographs of Astronomical Instruments made at the new works of the Geneva Society for the Manufacture of Scientific Instruments. These photographs ware sent by the Astronomer-Royal for Scotland.

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