Results 71 to 80 of about 10,210 (220)

Connecting VLBI and Gaia celestial reference frames

Frontiers 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

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 First Look of Gaia: Daily data quality and instrument health assessment with automated early warnings

Astronomy & Astrophysics
Context. The ESA Gaia mission is a 10+ year astrometric whole-sky scan,demanding consistent data quality over the whole timespan of operations Aims. The Gaia First Look (FL) is a system whose aim is monitoring the data quality to identify problems, which
Altmann M., Balog Z., Löffler W., Bastian U., Biermann M., Sagrista Selles A., Davidson M., Rowell N., Serpell E., Abreu Aramburu A., Brüsemeister T., Crowley C., Hauser M., Jordan S., Martín-Fleitas J., Mora A., del Peloso E. F., Stampa U.   +17 more
doaj   +1 more source

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

Journal 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, Edwin A. Quintero, Ivan D. Arellano-Ramírez   +2 more
doaj   +1 more source

Astrometry and the Virtual Observatory

, 2005
A primary goal of the Virtual Observatory (VO) is the integration of data from many instruments and wavelengths and creating source and objects lists to facilitate pan-chromatic science.
Schade, David
core  

Improved astrometry for the Bohannan & Epps catalogue

, 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 (1974, A&AS, 18, 47; BE74) catalogue of Hα ...
I. D. Howarth
core   +1 more source

Constraining the inclination of binary system orbits with the astrometric excess noise from Gaia DR3

Astronomy & Astrophysics
Context. Orbital inclination is crucial in determining the binary mass. The astrometric excess noise contains the orbital motion information, which can be used to constrain the inclination. Aims.
Liao Shilong, Ding Ye, Wen Shangyu, Qi Zhaoxiang, Wu Qiqi   +4 more
doaj   +1 more source

Astrometry And Data Centers [PDF]

Symposium - International Astronomical Union, 1988
SummaryThe paper tries to provide some background to answer the problem if old astrometric data should be stored. The cases of the AC and the CdC are examined, as well as the storage of some more recent catalogues on optical disc. Finally the necessity of producing general catalogues (of the SAO type) for non-astrometrists is underlined, to satisfy the
openaire   +1 more source

Towards high-precision ground-based astrometry: Differential delay lines for PRIMA@VLTI

, 2005
Deriving unambiguously the orbital parameters and masses of extrasolar planets requires at least 2-dimensional information on either the positions or motions of the planet directly (currently out of reach) or, indirectly, of the host star.
Launhardt, R., Bakker, E., Queloz, D., Hanenburg, H., Quirrenbach, H., de Jong, J., de Jong, J. A., Delplancke, F., Henning, Th., Bakker, E. J., Michellod, Y., Setiawan, J., Glindemann, A., Mathar, R. J., Pepe, F., Dändliker, R., Ségransan, D., Weber, L., Köhler, R., Fleury, M., Pragt, J., Sosnowska, D., Bizenberger, P., Baumeister, H., Jaffe, W., Venema, L., Mathar, R., Wüthrich, R., Murakawa, K., Maire, C., Tubbs, R., Reffert, S., Bleuler, H., Wagner, K., Le Poole, R. S., Sache, L., Gillet, D., Müllhaupt, P., le Poole, R., Derie, F., Tubbs, R. N., Quirrenbach, A., Scherler, O.   +42 more
core  

Space astrometry in the Gaia era and beyond

, 2015
In this contribution I provide some thoughts on the options for future space astrometry missions, with a focus on global astrometry. The next big step in space astrometry ideally would open up a new accuracy or wavelength domain (or a combination of both)
A.G.A. Brown
core   +1 more source