Results 21 to 30 of about 4,904 (168)

Bound Orbits and Epicyclic Motions around Renormalization Group Improved Schwarzschild Black Holes

open access: yesUniverse, 2022
We study timelike particles’ bound orbits around renormalization group improved Schwarzschild black holes (RGISBHs), which originate from renormalization group improvement of the Einstein–Hilbert action by using the running Newton constant.
Hou-Yu Lin, Xue-Mei Deng
doaj   +1 more source

VERA’s 20 yr Evolution in Science and Technology

open access: yesGalaxies
We review the past 20 yr evolution of VERA (VLBI Exploration of Radio Astrometry) in both science and techinology. VERA is a VLBI array in Japan which consists of four 20 m-diameter telescopes, originally dedicated to phase-referencing VLBI astrometry ...
Mareki Honma   +3 more
doaj   +1 more source

PERICLES: A Set of Empirical Rotational Isochrones Modeled on Cool Dwarfs in Open Clusters and Wide Binaries

open access: yesAstronomische Nachrichten, Volume 347, Issue 1, January 2026.
ABSTRACT Isochrones, equal‐age curves, are widely used in astrophysics to estimate stellar ages. Classical stellar parameters are, however, very limited in their usability for main sequence stars because of their weak age‐dependence. Here, rotation period measurements provide complementary information.
David Gruner, Sydney A. Barnes
wiley   +1 more source

Astrometry Lost and Regained

open access: yesOpen Astronomy, 2011
Technological and scientific developments during the past century made a new branch of astronomy flourish, i.e. astrophysics, and resulted in our present deep understanding of the whole Universe.
Høg E.
doaj   +1 more source

Connecting VLBI and Gaia celestial reference frames

open access: yesFrontiers in Astronomy and Space Sciences, 2016
The current state of the link problem between radio and optical celestial reference frames is considered.The main objectives of the investigations in this direction during the next few years are the preparation of a comparisonand the mutual orientation ...
Zinovy Malkin
doaj   +1 more source

Uncertainties in Historic Visual Double Star Measures—III Accurate Calibration Pairs

open access: yesAstronomische Nachrichten, Volume 346, Issue 10, December 2025.
ABSTRACT Based on space‐based positions and proper motions, we present accurate rectilinear elements for 857 double star pairs over the celestial sphere. These elements allow for the computation of precision ephemeris Position Angles and Separations of these pairs.
Roderick R. Letchford, Graeme L. White
wiley   +1 more source

Optimizing image processing for modern wide field surveys: enhanced data management based on the LSST science pipelines

open access: yesFrontiers in Astronomy and Space Sciences
Introduction: In recent decades, numerous large survey projects have been initiated to enhance our understanding of the cosmos. Among these, the Vera C.
Yuanyu Hong   +7 more
doaj   +1 more source

RESULTS OF PROCESSING OF ASTRONEGATIVES WITH COMMERCIAL SCANNER

open access: yesOdessa Astronomical Publications, 2014
Astrometric errors depending on the method of scanning with different spatial resolutions were studied  with commercial scanner such as   Epson Perfection V750 Pro.
Yu. I. Protsyuk   +3 more
doaj   +1 more source

Satellites and Small Bodies With ALMA: Insights Into Solar System Formation and Evolution

open access: yesAGU Advances, Volume 6, Issue 6, December 2025.
Abstract Our understanding of the formation and evolution of planetary systems has made major advances in the past decade. This progress has been driven in large part by the Atacama Large Millimeter/submillimeter Array (ALMA), which has given us an unprecedented view of solar system bodies themselves, and of the structure and chemistry of forming ...
Katherine de Kleer   +3 more
wiley   +1 more source

A Refined Astrometric Approach Based on the Precision Premium and its Application to the Jupiter’s Satellite Himalia

open access: yesThe Astronomical Journal
Since the advent of Gaia catalog, positional precision of a ground-based telescope can be greatly improved by correction of more subtle errors, including positional biases induced by atmospheric turbulence, and some instrumental factors such as geometric
Z. J. Zheng   +3 more
doaj   +1 more source

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