Results 51 to 60 of about 41,651 (296)

The Sirius System and Its Astrophysical Puzzles: Hubble Space Telescope and Ground-based Astrometry [PDF]

, 2017
Sirius, the seventh-nearest stellar system, is a visual binary containing the metallic-line A1 V star Sirius A, the brightest star in the sky, orbited in a 50.13 year period by Sirius B, the brightest and nearest white dwarf (WD).
H. Bond, H. E. Bond, Gail Schaefer, R. L. Gilliland, R. L. Gilliland, J. Holberg, Brian D. Mason, I. W. Lindenblad, M. Seitz-McLeese, W. D. Arnett, P. Demarque, F. Spada, Patrick A. Young, M. Barstow, M. Burleigh, D. Gudehus   +15 more
semanticscholar   +1 more source

Structure and kinematics of the Taurus star-forming region from Gaia-DR2 and VLBI astrometry [PDF]

Astronomy & Astrophysics, 2019
Aims. We take advantage of the second data release of the Gaia space mission and the state-of-the-art astrometry delivered from very long baseline interferometry observations to revisit the structure and kinematics of the nearby Taurus star-forming ...
P. Galli, L. Loinard, H. Bouy, L. Sarro, G. Ortiz-Léon, S. Dzib, J. Olivares, M. Heyer, Jesús Hernández, C. Román-Zúñiga, M. Kounkel, K. Covey   +11 more
semanticscholar   +1 more source

Commission 8: Astrometry [PDF]

Proceedings 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, I. Kumkova, Irina, Costa, E., Ducourant, C., W. Evans, D., Jin, W.-J., G. Lattanzi, M., Lu, C.-L., Scholz, R.-D., Sôma, M.   +9 more
openaire   +3 more sources

Orbital Parameter Determination for Wide Stellar Binary Systems in the Age of Gaia

, 2020
The orbits of binary stars and planets, particularly eccentricities and inclinations, encode the angular momentum within these systems. Within stellar multiple systems, the magnitude and (mis)alignment of angular momentum vectors among stars, disks, and ...
Dupuy, Trent J., Kraus, Adam L., Mann, Andrew W., Newton, Elisabeth R., Pearce, Logan A., Tofflemire, Benjamin N., Vanderburg, Andrew   +6 more
core   +1 more source

Reference-less detection, astrometry, and photometry of faint companions with adaptive optics [PDF]

, 2009
We propose a complete framework for the detection, astrometry, and photometry of faint companions from a sequence of adaptive optics corrected short exposures. The algorithms exploit the difference in statistics between the on-axis and off-axis intensity.
Beuzit, Biller, Born, Fitzgerald, Gladysz, Gladysz, Guyon, Hinkley, Itoh, Julian C. Christou, Labeyrie, Lafrenière, Marois, Marois, Masciadri, Roberts, Soummer, Soummer, Sparks, Szymon Gladysz   +19 more
core   +1 more source

Relativity in Astrometry [PDF]

Symposium - 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

Subluminal stochastic gravitational waves in pulsar-timing arrays and astrometry [PDF]

, 2020
The detection of a stochastic background of low-frequency gravitational waves by pulsar-timing and astrometric surveys will enable tests of gravitational theories beyond general relativity.
Wenzer Qin, K. Boddy, M. Kamionkowski
semanticscholar   +1 more source

A focus on L dwarfs with trigonometric parallaxes [PDF]

, 2018
This is an author-created, un-copyedited version of an article published in Publications of the Astronomical Society of the Pacific. Under embargo until 14 May 2019. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the
A. Burgasser, A. Luo, Allers K. N., B. Du, Basri G., Binney J., Blake C. H., Bouy H., Burgasser A. J., Burgasser A. J., Burgasser A. J., Burgasser A. J., Burgasser A. J. ed Mamajek E. E., Burgasser A. J. ed Singh H. P., Dupuy T. J., Dupuy T. J., F. Marocco, Faherty J. K., Faherty J. K., Faherty J. K., Gauza B., Gizis J. E., H. R. A Jones, J. Zhong, Kirkpatrick J. D., Kirkpatrick J. D., Kirkpatrick J. D., Kirkpatrick J. D., Knapp G. R., Luo A.-L., Lépine S., Mendez R. A., Pope B., Prato L., R. L. Smart, Reid I. N., Reiners A., Schmidt S. J., Skrutskie M. F., Stone R. C., Wang Y., Weinberger A. J., Wielen R., Y. Wang, York D. G., Z. Shao, Zapatero Osorio M. R.   +46 more
core   +3 more sources

Precise Dynamical Masses of Directly Imaged Companions from Relative Astrometry, Radial Velocities, and Hipparcos–Gaia DR2 Accelerations [PDF]

Astronomical Journal, 2018
We measure dynamical masses for five objects—three ultracool dwarfs, one low-mass star, and one white dwarf—by fitting orbits to a combination of the Hipparcos–Gaia Catalog of Accelerations, literature radial velocities, and relative astrometry.
Timothy D. Brandt, T. Dupuy, B. Bowler
semanticscholar   +1 more source

Binary deviations from single object astrometry [PDF]

Monthly notices of the Royal Astronomical Society, 2020
Most binaries are undetected. Astrometric reductions of a system using the assumption that the object moves like a single point mass can be biased by unresolved binary stars.
Z. Penoyre, V. Belokurov, N. Evans, A. Everall, Sergey E. Koposov   +4 more
semanticscholar   +1 more source