Results 111 to 120 of about 41,651 (296)

Tycho Astrometry and Photometry [PDF]

open access: yesSymposium - International Astronomical Union, 1986
The HIPPARCOS Star Mappers were designed to determine the satellite attitude by observation of stars with known positions. ESA has now enhanced them so that the continuous photon counts from two photo multipliers with B and V response will be recorded.
openaire   +4 more sources

Macho Photometry and Astrometry [PDF]

open access: yesSymposium - International Astronomical Union, 1995
MACHOs (Massive Astrophysical Compact Halo Objects) have been discovered by their relativistic amplification of light from distant stars as they crossed very near to the line-of-sight. The very few events were detected from more than a billion photometric measurements of millions of stars in the LMC.
Høg, E.   +2 more
openaire   +3 more sources

Review of asteroid, meteor, and meteorite‐type links

open access: yesMeteoritics &Planetary Science, Volume 60, Issue 4, Page 928-973, April 2025.
Abstract With the goal to determine the origin of our meteorites in the asteroid belt, video and photographic observations of meteors have now tracked 75 meteorite falls. Six years ago, there were just hints that different meteorite types arrived on different orbits, but now, the number of orbits (N) is high enough for distinct patterns to emerge.
Peter Jenniskens   +1 more
wiley   +1 more source

Detection of the nearest Jupiter analogue in radial velocity and astrometry data [PDF]

open access: yesMonthly notices of the Royal Astronomical Society, 2019
The presence of Jupiter is crucial to the architecture of the Solar system and models underline this to be a generic feature of planetary systems. We find the detection of the difference between the position and motion recorded by the contemporary ...
F. Feng   +6 more
semanticscholar   +1 more source

Overview of the Observing System and Initial Scientific Accomplishments of the East Asian VLBI Network (EAVN)

open access: yesGalaxies, 2022
The East Asian VLBI Network (EAVN) is an international VLBI facility in East Asia and is operated under mutual collaboration between East Asian countries, as well as part of Southeast Asian and European countries.
Kazunori Akiyama   +104 more
doaj   +1 more source

Micro-Arcsecond Radio Astrometry

open access: yes, 2013
Astrometry provides the foundation for astrophysics. Accurate positions are required for the association of sources detected at different times or wavelengths, and distances are essential to estimate the size, luminosity, mass, and ages of most objects ...
Honma, M., Reid, M. J.
core   +1 more source

Isolated Neutron Stars as Science Validation for XMM2ATHENA: Ensuring Robust Data for Future X‐Ray Astronomy

open access: yesAstronomische Nachrichten, Volume 346, Issue 3-4, March-May 2025.
ABSTRACT The discovery of radio‐quiet, x‐ray thermally emitting isolated neutron stars (XINSs) in the ROSAT All‐Sky Survey revealed a previously overlooked component of the neutron star population. Advancements in x‐ray instrumentation and the availability of deep, wide‐area optical surveys now enable us to explore XINSs at fainter x‐ray fluxes and ...
Adriana Mancini Pires   +11 more
wiley   +1 more source

Detecting dark photon dark matter with Gaia-like astrometry observations [PDF]

open access: yesJournal of Cosmology and Astroparticle Physics, 2019
A class of dark photon dark matter models with ultralight masses would lead to oscillation of a test body through a coupling with baryons or B−L charge. This periodical oscillation of an observer results in swing of a star's apparent position due to the ...
Huai-Ke Guo   +5 more
semanticscholar   +1 more source

Prospects of dynamical determination of General Relativity parameter beta and solar quadrupole moment J2 with asteroid radar astronomy

open access: yes, 2017
We evaluated the prospects of quantifying the parameterized post-Newtonian parameter beta and solar quadrupole moment J2 with observations of near-Earth asteroids with large orbital precession rates (9 to 27 arcsec century$^{-1}$). We considered existing
Greenberg, Adam H.   +2 more
core   +1 more source

Pulsar Astrometry [PDF]

open access: yesSymposium - International Astronomical Union, 1984
High precision measurements of the celestial coordinates of pulsars are desirable for a number of reasons. If carried out at several epochs, the measurements can yield angular proper motions; together with distance estimates based on dispersion measure, the proper motion of a pulsar reveals two of three components of its space velocity, and ...
Joseph H. Taylor   +3 more
openaire   +1 more source

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