Results 81 to 90 of about 33,599 (258)

Nature in Seclusion. The Monastic Republic of Letters in Southern Germany**

Berichte zur Wissenschaftsgeschichte, Volume 47, Issue 3, Page 215-241, September 2024.
Abstract Monasteries were famous for their extensive libraries and richly decorated churches. Less well known are their observatories and their mathematical‐physical collections with telescopes, air pumps, and friction machines. But how did the way of life in the monastery and scientific practices influence each other?
Julia Bloemer
wiley   +1 more source

Astrometry with the Keck-Interferometer: the ASTRA project and its science

, 2008
The sensitivity and astrometry upgrade ASTRA of the Keck Interferometer is introduced. After a brief overview of the underlying interferometric principles, the technology and concepts of the upgrade are presented.
Andrea M. Ghez, Andrew Cooper, Ben Berkey, Bill Randolph, Boden, Bouchez, Brett Smith, Colavita, Colavita, Colavita, Colette Tyau, Delplancke, Douglas Morrison, Drew Medeiros, Ed Wetherell, Eisner, Eliot Quataert, Esposito, Ghez, Ghez, Gillessen, Gilmozzi, Haniff, James R. Graham, John Monnier, Jorg-Uwe Pott, Josh A. Eisner, Julien Woillez, Kellee Summers, Kevin Tsubota, Labeyrie, Lynne Hillenbrand, Mark M. Colavita, Michael Hrynewych, Monnier, Nevin Weinberg, Peter L. Wizinowich, Pott, Rachel L. Akeson, Rafael Millan-Gabet, Santos, Shao, Tatyana Panteleeva, Vasisht, Weigelt   +44 more
core   +1 more source

METHOD FOR EVALUATING THE ASTROMETRIC AND PHOTOMETRIC CHARACTERISTICS OF COMMERCIAL SCANNERS IN THEIR APPLICATION FOR THE SCIENTIFIC PURPOSE

Odessa Astronomical Publications, 2014
Method  for estimating the accuracy of astrometric  (rectangular coordinates) and photometric (diameters and magnitudes) characteristics of commercial scanners is proposed and applied.
Yu. I. Protsyuk, V. N. Andruk, M. M. Muminov, Q. X. Yuldoshev, Sh. A. Ehgamberdiev, I. Eglitis, M. Eglite, O. E. Kovylianska, V. V. Golovnya, L. V. Kazantseva, S. G. Kashuba   +10 more
doaj   +1 more source

Multi‐Instrument and SAMI3‐TIDAS Data Assimilation Analysis of Three‐Dimensional Ionospheric Electron Density Variations During the April 2024 Total Solar Eclipse

Journal of Geophysical Research: Space Physics, Volume 129, Issue 9, September 2024.
Abstract This paper conducts a multi‐instrument and data assimilation analysis of the three‐dimensional ionospheric electron density responses to the total solar eclipse on 08 April 2024. The altitude‐resolved electron density variations over the continental US and adjacent regions are analyzed using the Millstone Hill incoherent scatter radar data ...
Ercha Aa, Joseph Huba, Shun‐Rong Zhang, Anthea J. Coster, Philip J. Erickson, Larisa P. Goncharenko, Juha Vierinen, William Rideout   +7 more
wiley   +1 more source

Magnetic Field Studies in BL Lacertae through Faraday Rotation and a Novel Astrometric Technique

Galaxies, 2017
It is thought that dynamically important helical magnetic fields twisted by the differential rotation of the black hole’s accretion disk or ergosphere play an important role in the launching, acceleration, and collimation of active galactic nuclei (AGN ...
Sol N. Molina, José L. Gómez, Richard Dodson, María J. Rioja   +3 more
doaj   +1 more source

COMMISSION 8: ASTROMETRY [PDF]

Proceedings of the International Astronomical Union, 2011
Gaia is continuing well with its development and construction and is expected to achieve parallax accuracies of about 10 to 300 muas for 6 to 20 mag. It is scheduled to launch in 2013.
Evans, Dafydd W., Zacharias, Norbert, Kumkova, Irina, Andrei, Alexandre Humberto, Brown, Anthony, Gouda, Naoteru, Popescu, Petre, Souchay, Jean, Unwin, Stephen C., Zhu, Z.   +9 more
openaire   +2 more sources

Revisiting the Excitation of Free Core Nutation

Journal of Geophysical Research: Solid Earth, Volume 129, Issue 9, September 2024.
Abstract Earth possesses a Poincaré mode called Free Core Nutation (FCN) due to the misalignment of the rotation axes of the mantle and fluid outer core. FCN is the primary signal in the observations of Celestial Pole Offsets (CPO) and maintained by geophysical mechanisms that are yet to be understood. Earlier studies suggested an origin in Atmospheric
Mostafa Kiani Shahvandi, Michael Schindelegger, Lara Börger, Siddhartha Mishra, Benedikt Soja   +4 more
wiley   +1 more source

Direct-imaging Discovery of a Substellar Companion Orbiting the Accelerating Variable Star HIP 39017

The Astronomical Journal
We present the direct-imaging discovery of a substellar companion (a massive planet or low-mass brown dwarf) to the young, γ Doradus ( γ Dor)-type variable star HIP 39017 (HD 65526). The companion’s SCExAO/CHARIS JHK (1.1–2.4 μ m) spectrum and Keck/NIRC2
Taylor L. Tobin, Thayne Currie, Yiting Li, Jeffrey Chilcote, Timothy D. Brandt, Brianna Lacy, Masayuki Kuzuhara, Maria Vincent, Mona El Morsy, Vincent Deo, Jonathan P. Williams, Olivier Guyon, Julien Lozi, Sebastien Vievard, Nour Skaf, Kyohoon Ahn, Tyler Groff, N. Jeremy Kasdin, Taichi Uyama, Motohide Tamura, Aidan Gibbs, Briley L. Lewis, Rachel Bowens-Rubin, Maïssa Salama, Qier An, Minghan Chen   +25 more
doaj   +1 more source

ASTROMETRY OF Χ AND H PERSEI BASED ON PROCESSING OF DIGITIZED PLATES OF ARCHIVE OF THE ASTRONOMICAL INSTITUTE OF THE ACADEMY OF SCIENCES OF THE REPUBLIC OF UZBEKISTAN

Odessa Astronomical Publications, 2014
Work is done  with Epson Expression 10000XL scanner  of  Astronomical Institute  (AI)  of theAcademyofSciencesofUzbekistan. The plates were exposed  with theNormalastrograph (D/F = 330mm / 3467mm, M = 59.56"/mm). The  digitization  of  plates with(16x16)
M. M. Muminov, Q. X. Yuldoshev, Sh. A. Ehgamberdiev, B. B. Kahharov, V. N. Andruk, Yu. I. Protsyuk   +5 more
doaj   +1 more source

JWST imaging of the closest globular clusters—I. Possible infrared excess among white dwarfs in NGC 6397

Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We present James Webb Space Telescope observations of the globular cluster NGC 6397 and use them to extend to infrared wavelengths the characterization of the cluster's entire white dwarf (WD) cooling sequence (CS). The data allows us to probe fundamental astrophysical WD properties and to search for evidence in their colors for (or against ...
L. R. Bedin, D. Nardiello, M. Salaris, M. Libralato, P. Bergeron, A. J. Burgasser, D. Apai, M. Griggio, M. Scalco, J. Anderson, R. Gerasimov, A. Bellini   +11 more
wiley   +1 more source