Results 31 to 40 of about 32,900 (194)

Evidence for a 304-day Orbital Period for GX 1+4 [PDF]

, 1999
In this paper we report strong evidence for a ~304-day periodicity in the spin history of the accretion-powered pulsar GX 1+4 that is very likely to be a signature of the orbital period of the system.
Braga, Joao, Jablonski, Francisco J., Pereira, Marildo G.   +2 more
core   +3 more sources

A cyclical period variation detected in the updated orbital period analysis of TV Columbae [PDF]

, 2010
The two CCD photometries of the intermediate polar TV Columbae are made for obtaining the two updated eclipse timings with high precision. There is an interval time \sim 17yr since the last mid-eclipse time observed in 1991.
A. Retter, B.A. Cooke, C. Hellier, C. Hellier, C. Motch, D.A. Smith, Eduardo Fernández Lajús, G. L. Baume, G. Ramsey, J. Schrijver, J.B. Hutchings, J.H. Applegate, K. Beuermann, M. Cropper, M. Ishida, S.D. Vrtilek, Shengbang Qian, T. Augusteijn, V.R. Rana, Z.B. Dai, Z.B. Dai, Zhibin Dai   +21 more
core   +3 more sources

Performance of Multi-GNSS in the Asia-Pacific Region: Signal Quality, Broadcast Ephemeris and Precise Point Positioning (PPP)

Remote Sensing, 2022
Since BeiDou Navigation Satellite System (BDS) and Japan’s Quasi-Zenith Satellite System (QZSS) have more visible satellites in the Asia-Pacific region, and navigation satellites of Global Positioning System (GPS), Galileo satellite navigation system ...
Mengyuan Li, Guanwen Huang, Le Wang, Wei Xie, Fan Yue   +4 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, Burwitz, Vadim, Gauza, Bartosz, Gozdziewski, Krzysztof, Haghighipour, Nader, Hinse, Tobias C., Kanbach, Gottfried, Maciejewski, Andrzej J., Nasiroglu, Ilham, Rau, Arne, Schwarz, Robert, Schwope, Axel D., Slonina, Mariusz, Slowikowska, Aga   +13 more
core   +1 more source

Spitzer Observations of GX17+2: Confirmation of a Periodic Synchrotron Source [PDF]

, 2011
GX17+2 is a low-mass X-ray binary (LMXB) that is also a member of a small family of LMXBs known as "Z-sources" that are believed to have persistent X-ray luminosities that are very close to the Eddington limit. GX17+2 is highly variable at both radio and
Bornak, Jillian, Gelino, Christopher R., Gelino, Dawn M., Harrison, Thomas E., McNamara, Bernard J., Rupen, Michael P., Wachter, Stefanie   +6 more
core   +1 more source

Discovery of periodic dips in the light curve of GX 13+1: the X-ray orbital ephemeris of the source [PDF]

, 2013
The bright low-mass X-ray binary (LMXB) GX 13+1 is one of the most peculiar Galactic binary systems. A periodicity of 24.27 d with a formal statistical error of 0.03 d was observed in its power spectrum density obtained with RXTE All Sky Monitor (ASM ...
Burderi, L., D'Ai, A., Di Salvo, T., Iaria, R., Riggio, A., Robba, N. R.   +5 more
core   +2 more sources

Digital Twin‐Based Optimization of Service Availability in LEO Mega Constellations Considering Handover Delays in Open RAN

International Journal of Satellite Communications and Networking, EarlyView.
ABSTRACT As non‐terrestrial networks (NTNs) become integral to future 6G systems, ensuring seamless connectivity and service continuity over low Earth orbit (LEO) satellite constellations is essential. This work investigates the impact of open radio access network (RAN) functional splits on handover performance in NTNs, focusing on minimizing service ...
Siva Satya Sri Ganesh Seeram, Luca Feltrin, Mustafa Ozger, Cicek Cavdar   +3 more
wiley   +1 more source

Improved Chebyshev series ephemeris generation capability of GTDS [PDF]

, 1980
An improved implementation of the Chebyshev ephemeris generation capability in the operational version of the Goddard Trajectory Determination System (GTDS) is described.
Jacintho, J. J., Liu, S. Y., Rogers, J.
core   +1 more source

Holistic Retrieval of Absolute Coseismic Displacement Fields From Single Interferograms via Physics‐Aware GANs

Geophysical Research Letters, Volume 53, Issue 6, 28 March 2026.
Abstract The efficacy of rapid seismic response is fundamentally constrained by the sequential, multi‐step nature of conventional InSAR processing, where error propagation and reliance on auxiliary data hinder automation. Here, we present a holistic framework using Physics‐Aware Generative Adversarial Networks (GANs) to directly retrieve absolute ...
Chuanhua Zhu, Jiaqiao Gan, Zuqi Lan, Chisheng Wang   +3 more
wiley   +1 more source

Updating the orbital ephemeris of Her X-1; rate of decay and eccentricity of the orbit

, 2009
We present an update of the orbital ephemeris of the binary X-ray pulsar Her X-1 and determine an improved value for the rate of orbital decay. In addition, we report the first measurement of the orbital eccentricity.
Bradt, Crampton, D'Souza, D. Klochkov, Deeter, Deeter, Deeter, Gerend, Giacconi, Holt, Howarth, J. Wilms, Kelley, Klochkov, Lampton, Leahy, Liller, Marsh, Nagase, Parmar, Parmar, R. Staubert, Reynolds, Rots, Ruderman, Shakura, Staubert, Staubert, Tananbaum, Ubertini, Vrtilek, Walter, Winkler   +32 more
core   +1 more source