Results 31 to 40 of about 7,595 (254)

Relativity in Astrometry [PDF]

open access: yesSymposium - International Astronomical Union, 1986
The coordinate dependence of the definition of light deflexion is discussed and the concepts of “natural” and “proper” reference frame are introduced in order to derive astrometric observables from coordinate quantities. Confusion in published formulations of VLBI data analysis is discussed in the context of the IAU definition of the coordinate time ...
openaire   +1 more source

Gaia: The Astrometry Revolution [PDF]

open access: yesProceedings of the International Astronomical Union, 2015
AbstractThe power of micro-arcsecond (μas) astrometry is about to be unleashed. ESA's Gaia mission, now headed towards the end of the first year of routine science operations, will soon fulfil its promise for revolutionary science in countless aspects of Galactic astronomy and astrophysics.
SOZZETTI, Alessandro   +4 more
openaire   +5 more sources

Halometry from astrometry [PDF]

open access: yesJournal of Cosmology and Astroparticle Physics, 2018
Halometry---mapping out the spectrum, location, and kinematics of nonluminous structures inside the Galactic halo---can be realized via variable weak gravitational lensing of the apparent motions of stars and other luminous background sources. Modern astrometric surveys provide unprecedented positional precision along with a leap in the number of ...
Neal Weiner   +2 more
openaire   +3 more sources

Optical Forbidden Emission Line Spectro-astrometry of T CrA: Evidence for a Multiple System and Multiple Jets

open access: yesThe Astrophysical Journal, 2023
Spectro-astrometry is applied to echelle spectra of the young intermediate-mass star T CrA. The aim is to better understand the origin of the [O i ] and [S ii ] emission from T CrA and further explore the usefulness of spectro-astrometry in the search ...
E. T. Whelan, A. Murphy, I. Pascucci
doaj   +1 more source

Improved astrometry for the Bohannan & Epps catalogue [PDF]

open access: yes, 2012
Aims: Accurate astrometry is required to reliably cross-match 20th-century catalogues against 21st-century surveys. The present work aims to provide such astrometry for the 625 entries of the Bohannan & Epps (BE74) catalogue of H$\alpha$ emission-line stars.
arxiv   +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

Improved Orbital Constraints and Hα Photometric Monitoring of the Directly Imaged Protoplanet Analog HD 142527 B

open access: yesThe Astronomical Journal, 2022
Companions embedded in the cavities of transitional circumstellar disks have been observed to exhibit excess luminosity at H α , an indication that they are actively accreting.
William O. Balmer   +11 more
doaj   +1 more source

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

open access: yesOdessa 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   +2 more
doaj   +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

open access: yesOdessa 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

Determination of Orbital Elements and Ephemerides using the Geocentric Laplace’s Method

open access: yesJournal of Astronomy and Space Sciences, 2020
This paper presents a methodology for Initial Orbit Determination (IOD) based on a modification of the Laplace’s geocentric method. The orbital elements for Near-Earth asteroids (1864) Daedalus, 2003 GW, 2019 JA8, a Hungaria-type asteroid (4690 ...
Daniela Espitia   +2 more
doaj   +1 more source

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