Results 101 to 110 of about 41,139 (300)
Uncertainties in Ground‐Based Visual Double Star Measures
Astronomische Nachrichten, Volume 346, Issue 2, February 2025.ABSTRACT Stellar masses are found from the orbital elements of binary systems which are, in turn, computed from weighted astrometric measures. Astrometric measures of double stars (their position angle and separation) rarely include uncertainties, and published binary star orbits rarely include the weighting systems used in the determination of the ...
Roderick R. Letchford, Graeme L. White
wiley +1 more source
NavigationPlans to establish a satellite network around the Moon to support communication, position, navigation, and timing services are rapidly evolving. Satellites that are part of this system broadcast their ephemeris as finite parameters to lunar users for ...
Marta Cortinovis +2 more
doaj +1 more source
On the HU Aquarii planetary system hypothesis
, 2012 In this work, we investigate the eclipse timing of the polar binary HU Aquarii that has been observed for almost two decades. Recently, Qian et al. attributed large (O-C) deviations between the eclipse ephemeris and observations to a compact system of ...
Beuermann, Klaus +13 more
core +1 more source
The Orbital Ephemeris and X-Ray Light Curve of Cyg X-3 [PDF]
, 1997 The orbital dynamics of Cyg X-3 are a key to understanding this enigmatic X-ray binary. Recent observations by the RXTE ASM and the OSSE instrument on GRO enable us to extend the baseline of arrival time measurements and test earlier models of orbital ...
Matz, Steven M.
core +3 more sources
The optical ephemeris and X-ray variability of 4U 1735-44 (V926 Sco) [PDF]
arXiv, 2012 Optical observations of the low mass X-ray binary 4U 1735-44 were obtained during 1997-2007 and combined with earlier published observations from 1984-1993 to refine the ephemeris for the system. The linear fit for the time of maximum optical light has the ephemeris HJD = 2445904.0494(90) + [ N x 0.19383222(29)] with a value of chi^2 = 253.5$ for 16 ...
arxiv
Validity of the relations between the synodic and sidereal rotation velocities of the Sun [PDF]
, 2013 Existing methods for conversion between synodic and sidereal rotation velocities of the Sun are tested for validity using state of the art ephemeris data. It is found that some of them are in good agreement with ephemeris calculations, while the other ones show a discrepancy of almost 0.01 deg per day.
arxiv +1 more source
Ecology and Evolution, Volume 15, Issue 2, February 2025.Our study shows that the landscape‐scale environmental gradient represented as ecotone and as local environmental factors can alternately determine the spatial structures of the floodplain biota across seasons. The study highlights the understudied yet important linkages of spatial and temporal biotic assemblages and advance understanding of ecology ...
Hiromi Uno +5 more
wiley +1 more source
Transit observations at the observatory in Grossschwabhausen: XO-1b and TrES-1 [PDF]
, 2008 We report on observations of transit events of the transiting planets XO-1b and TrES-1 with the AIU Jena telescope in Grossschwabhausen. Based on our IR photometry (in March 2007) and available transit timings (SuperWASP, XO and TLC-project-data) we ...
A. Koeltzsch +12 more
core +2 more sources
AGU Advances, Volume 6, Issue 1, February 2025.Abstract The magnetometer investigation of the Galileo mission used the phenomenon of magnetic induction to produce the most compelling evidence that subsurface oceans exist within our solar system. Although there is high certainty that the induced field measured at Europa is attributed to a global‐scale subsurface ocean, there is still uncertainty ...
Corey J. Cochrane +4 more
wiley +1 more source