Results 21 to 30 of about 4,915 (213)

Milky Way Star Clusters and Gaia: A Review of the Ongoing Revolution

open access: yesUniverse, 2022
The unprecedented quality of the astrometric measurements obtained with the ESA Gaia spacecraft have initiated a revolution in Milky Way astronomy. Studies of star clusters in particular have been transformed by the precise proper motions and parallaxes ...
Tristan Cantat-Gaudin
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

Simulation study of asteroid mass determination using CSST asteroid observations

open access: yesFrontiers in Astronomy and Space Sciences, 2023
The objective of this study is to explore the potential of the Chinese Space Station Telescope (CSST) in asteroid mass determination with asteroid-asteroid close encounters.
Fan Li   +4 more
doaj   +1 more source

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

Astrometry and Relativity

open access: yesIl Nuovo Cimento B, 2005
General relativistic effects in astrophyiscal systems have been detected thanks to accurate astrometric measurements. We outline some keystones of astrometry such as stellar aberration (argument development during the years 1727-1872); Mercury's perihelion precession (1845-1916); solar disk oblateness (1966-2001); relativistic light deflection (1916 ...
openaire   +2 more sources

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

Space astrometry with the Joint Milliarcsecond Astrometry Pathfinder [PDF]

open access: yesProceedings of the International Astronomical Union, 2009
AbstractThe Joint Milliarcsecond Astrometry Pathfinder Survey (JMAPS) is a small, space-based, all sky, visible wavelength, astrometric and photometric survey mission for 0ththrough 14thI-band magnitude stars with a planned 2013 launch. The primary objective of the JMAPS mission is the generation of an astrometric star catalog with 1 milliarcsecond ...
Gregory S. Hennessy, Ralph Gaume
openaire   +1 more source

Commission 8: Astrometry [PDF]

open access: yesProceedings of the International Astronomical Union, 2005
AbstractThis triennial report from Commission 8 covers astrometry-related matters for objects ranging from Solar system bodies out to Milky Way stars and QSOs at cosmological distances. This enormous range of distances is needed to establish, maintain, and improve the metric of the visible Universe--a very challenging effort since everything is moving.
Platais, Imants   +9 more
openaire   +2 more sources

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

open access: yesAstronomische Nachrichten, EarlyView.
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

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