Results 31 to 40 of about 669,418 (322)

The eROSITA X-ray telescope on SRG [PDF]

open access: yesAstronomy & Astrophysics, 2020
eROSITA (extended ROentgen Survey with an Imaging Telescope Array) is the primary instrument on the Spectrum-Roentgen-Gamma (SRG) mission, which was successfully launched on July 13, 2019, from the Baikonour cosmodrome.
P. Predehl   +92 more
semanticscholar   +1 more source

Receiving vectors of muon telescope of cosmic ray station Novosibirsk

open access: yesSolar-Terrestrial Physics, 2016
The method of receiving vectors allows us to determine cosmic ray anisotropy at every moment of time. Also, the method makes it possible to study fast anisotropy fluctuations related to the interplanetary medium dynamics.
Yanchukovsky V.L.   +4 more
doaj   +1 more source

Imagining the Heavens: Adam Elsheimer’s Flight into Egypt and the Renaissance Night Sky

open access: yesJournal for the History of Knowledge, 2021
Adam Elsheimer’s The Flight into Egypt (1609) has triggered a longstanding debate among art historians. For the last five decades, Elsheimer’s novel naturalistic representation of the night sky in his painting on copper has been linked to Galileo’s ...
Stefan Zieme
doaj   +1 more source

First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring [PDF]

open access: yesAstrophysical Journal, 2019
The Event Horizon Telescope (EHT) has mapped the central compact radio source of the elliptical galaxy M87 at 1.3 mm with unprecedented angular resolution. Here we consider the physical implications of the asymmetric ring seen in the 2017 EHT data.
K. Akiyama   +220 more
semanticscholar   +1 more source

First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole [PDF]

open access: yesAstrophysical Journal, 2019
We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ~40 μas, consistent with the size and shape of the lensed photon orbit ...
K. Akiyama   +214 more
semanticscholar   +1 more source

Wishing for the Watch Face in Jonathan Swift’s “The Progress of Beauty”

open access: yesABO : Interactive Journal for Women in the Arts 1640-1830, 2018
This article illuminates the technological underpinnings of Jonathan Swift’s satire, “The Progress of Beauty” (1719), by exploring how eighteenth-century poetics of beauty and scientific progress pit human against automaton.
Jantina Ellens
doaj   +1 more source

Comparative analysis of three mode-selection methods for solid-state lasers [PDF]

open access: yesE3S Web of Conferences, 2021
In the Nd3+:YAG pulsed Q-switched laser system, the selective output of several low order modes of TEM00, TEM01 and TEM11 is realized by adding a iris diaphragm, a telescope or a Gaussian mirror at an appropriate position in the resonator, and the three ...
Sun Yan
doaj   +1 more source

Atmospheric Conditions within Big Telescope Alt-Azimuthal Region and Possibilities of Astronomical Observations

open access: yesRemote Sensing, 2022
The paper presents the results of analysis of astroclimatic conditions in the Big Telescope Alt-azimuthal (BTA) region (40°N–50°N; 35°E–55°E). Using data from the European center for medium-range weather forecast ReAnalysis (ERA-5), we estimated the ...
Artem Yu. Shikhovtsev   +8 more
doaj   +1 more source

Building a CCD Spectrograph for Educational or Amateur Astronomy [PDF]

open access: yes, 2002
We discuss the design of an inexpensive, high-throughput CCD spectrograph for a small telescope. By using optical fibers to carry the light from the telescope focus to a table-top spectrograph, one can minimize the weight carried by the telescope and ...
Charles B. Hughes   +4 more
core   +1 more source

Fermi Large Area Telescope Fourth Source Catalog [PDF]

open access: yesAstrophysical Journal Supplement Series, 2019
We present the fourth Fermi Large Area Telescope catalog (4FGL) of γ-ray sources. Based on the first eight years of science data from the Fermi Gamma-ray Space Telescope mission in the energy range from 50 MeV to 1 TeV, it is the deepest yet in this ...
S. Abdollahi   +167 more
semanticscholar   +1 more source

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