Results 31 to 40 of about 4,904 (168)

SOFTWARE FOR PROCESSING OF DIGITIZED ASTRONEGATIVES FROM ARCHIVES AND DATABASES OF VIRTUAL OBSERVATORY

Odessa Astronomical Publications, 2014
The paper discusses and illustrates the steps of  basic processing  of  digitized image of astro negatives. Software for  obtaining of a  rectangular coordinates and photometric values of objects on photographic plates was created in the environment ...
Yu. I. Protsyuk, L. V. Kazantseva, V. N. Andruk   +2 more
doaj   +1 more source

Globally Critical Infrastructure: The Unique Risks and Challenges

Risk Analysis, Volume 45, Issue 12, Page 4804-4817, December 2025.
ABSTRACT Critical infrastructure is typically identified at the national level. However, disruption to certain infrastructure systems, facilities, and assets can have negative consequences for global societies. Such globally critical infrastructure entails a distinct risk profile for both countries dependent on the infrastructure, and countries that ...
Zachary Kallenborn, Henry H. Willis
wiley   +1 more source

A DIFFERENTIAL CATALOGUE OF RIGHT ASCENSIONS OF 263 RRS2 STARS OBTAINED FROM OBSERVATIONS MADE WITH THE ODESSA MERIDIAN CIRCLE IN 1990-1993

Odessa Astronomical Publications, 2017
This catalogue contains the results of 1321 right ascensions observations of 2dj Radio References Stars obtained al Odessa with the Repsold transit circle in 1990-1993.
A. P. Chelombit'ko
doaj   +1 more source

JWST Imaging of the Closest Globular Clusters—VI. The Lowest‐Mass Objects in M 4 and the Galactic Bulge

Astronomische Nachrichten, Volume 346, Issue 9, November 2025.
ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin, R. Gerasimov, A. Calamida, M. Libralato, M. Scalco, D. Nardiello, M. Griggio, D. Apai, J. Anderson, A. Bellini, A. Burgasser   +10 more
wiley   +1 more source

The Orbits of Uranus, Its Satellites and Rings, the Gravity Field of the Uranian System, and the Orientation of the Poles of Uranus and Its Satellites

The Astronomical Journal
R. A. Jacobson determined the orbits of the Uranian satellites, the masses of Uranus and its satellites, and the orientation of the pole of Uranus from Earth-based astrometry, Earth-based ring occultations, and observations acquired with the Voyager 2 ...
Robert A. Jacobson, Ryan S. Park
doaj   +1 more source

Mining of the Milky Way Star Archive Gaia-DR2. Searching for Binary Stars in Planetary Nebulae

Proceedings, 2020
The aim of this work is to search for binary stars associated to planetary nebulae (ionized stellar envelopes in expansion), by mining the astronomical archive of Gaia DR2, that is composed by around 1.7 billion stellar sources.
Iker González-Santamaría, Minia Manteiga, Carlos Dafonte, Arturo Manchado, Ana Ulla   +4 more
doaj   +1 more source

Integration of Statistical Models and Deep Learning: A CEEMDAN‐Based Hybrid Framework for Frequency‐Domain Prediction of Polar Motion

Earth and Space Science, Volume 12, Issue 10, October 2025.
Abstract High‐precision Earth Rotation Parameter (ERP) products often experience delays that range from several days to weeks. The use of precise forecasting models can effectively compensate for the impact of such delays. Based on a systematic analysis of the forecasting capabilities of the traditional harmonic least squares fitting and autoregressive
Chen Ren, Chen Wang, Zhenhong Li, Haoran Gong, Jialiang Liu   +4 more
wiley   +1 more source

Astrometric star catalogues as combination of Hipparcos/Tycho catalogues with ground-based observations [PDF]

Serbian Astronomical Journal, 2004
The successful ESA mission Hipparcos provided very precise parallaxes positions and proper motions of many stars in optical wavelength. Therefore it is a primary representation of International Celestial Reference System in this wavelength.
Vondrák J.
doaj   +1 more source

Reassessing the Relationship Between Meteor Radio Afterglows and Optical Persistent Trains

Journal of Geophysical Research: Space Physics, Volume 130, Issue 9, September 2025.
Abstract Meteor radio afterglows (MRAs) and optical persistent trains (PTs) are two types of long‐lived phenomena which are occasionally observed following the occurrence of a meteor. Both phenomena are thought to be produced by intrinsic emission mechanisms; PTs have been associated with chemiluminescent reactions between meteoric metals and ...
L. E. Cordonnier, K. S. Obenberger, G. B. Taylor, J. M. Holmes, J. Dowell, D. Vida   +5 more
wiley   +1 more source

The Power of (Near) Simultaneous Multi-Frequency Observations for mm-VLBI and Astrometry

Galaxies, 2017
Simultaneous or near-simultaneous observations at multiple frequency bands have the potential to overcome the fundamental limitation imposed by the atmospheric propagation in mm-VLBI observations.
María J. Rioja, Richard Dodson, José L. Gómez, Sol N. Molina, Taehyun Jung, Bong Won Sohn   +5 more
doaj   +1 more source