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Related papers: Difficulties of Preserving the Leap Second

200 papers

The Hipparcos catalog and its Double and Multiple System Annex (DMSA) lists 4099 components with individual proper motions and coordinates on the epoch 1991.25. Many of these long-period binary stars are also present in the Gaia Data…

Solar and Stellar Astrophysics · Physics 2020-12-02 Valeri V. Makarov

We discuss the latest constraints on a Taylor-expanded scalar inflaton potential, obtained focusing on its observable part only. This is in contrast with other works in which an extrapolation of the potential is applied using the slow-roll…

Astrophysics · Physics 2009-06-23 Wessel Valkenburg

We propose to use a modest fraction of the re-purposed Kepler mission time and apertures to greatly increase the quantity and quality of our knowledge of near-Earth asteroids (NEAs) rotation and shape. NEAs are important for understanding…

Earth and Planetary Astrophysics · Physics 2013-09-11 Martin Elvis , José Luis Galache , Gareth V. Williams

Analysis of transit times in exoplanetary systems accurately provides an instantaneous orbital period, $P(t)$, of their member planets. A long-term monitoring of those transiting planetary systems puts limits on the variability of $P(t)$,…

General Relativity and Quantum Cosmology · Physics 2016-03-21 Kento Masuda , Yasushi Suto

Run II of the Tevatron Collider is reviewed, emphasizing operations through March 15, 2004. The Run II Luminosity Upgrade plans and luminosity projections through 2009 are discussed.

High Energy Physics - Experiment · Physics 2007-05-23 Peter H. Garbincius

It is customary to perform analysis of the Earth's rotation in two steps: first, to present results of estimation of the Earth orientation parameters in the form of time series based on a simplified model of variations of the Earth's…

Astrophysics · Physics 2010-12-14 L. Petrov

Stellar rotation is a complex function of mass, metallicity, and age and can be altered by binarity. To understand the importance of these parameters in main sequence stars, we have assembled a sample of observations that spans a range of…

We present time-series Doppler images of the rapidly-rotating active binary star EI Eri from spectroscopic observations collected during the MUSICOS multi-site campaign in 1998, since the critical rotation period of 1.947 days makes it…

Astrophysics · Physics 2015-05-13 Zs. Kővári , A. Washuettl , B. H. Foing , K. Vida , J. Bartus , K. Oláh , the MUSICOS 98 team

As new concepts of sending interstellar spacecraft to the nearest stars are now being investigated by various research teams, crucial questions about the timing of such a vast financial and labor investment arise. If humanity could build…

Popular Physics · Physics 2017-07-18 René Heller

We present 25 new eclipse times of the white dwarf binary NN Ser taken with the high-speed camera ULTRACAM on the WHT and NTT, the RISE camera on the Liverpool Telescope, and HAWK-I on the VLT to test the two-planet model proposed to…

Solar and Stellar Astrophysics · Physics 2015-06-17 T. R. Marsh , S. G. Parsons , M. C. P. Bours , S. P. Littlefair , C. M. Copperwheat , V. S. Dhillon , E. Breedt , C. Caceres , M. R. Schreiber

Duration of the extended solar cycles is taken into the consideration. The beginning of cycles is counted from the moment of polarity reversal of large-scale magnetic field in high latitudes, occurring in the sunspot cycle n till the…

Astrophysics · Physics 2009-11-13 A. G. Tlatov

Before atomic timekeeping, clocks were set to the skies. But starting in 1972, radio signals began broadcasting atomic seconds and leap seconds have occasionally been added to that stream of atomic seconds to keep the signals synchronized…

Instrumentation and Methods for Astrophysics · Physics 2011-06-17 David Finkleman , Steve Allen , John Seago , Rob Seaman , P. Kenneth Seidelmann

The stellar Rotation $vs.$ Age relation is commonly considered as a useful tool to derive reliable ages for Sun-like stars. However, in the light of \kepler\ data, the presence of apparently old and fast rotators that do not obey the usual…

We imaged comet 10P/Tempel 2 on 32 nights from 1999 April through 2000 March. R-band lightcurves were obtained on 11 of these nights from 1999 April through 1999 June, prior to both the onset of significant coma activity and perihelion.…

Earth and Planetary Astrophysics · Physics 2015-05-20 Matthew M. Knight , Tony L. Farnham , David G. Schleicher , Edward W. Schwieterman

After observing WASP-12 in the second year of the primary mission, the Transiting Exoplanet Survey Satellite (TESS) revisited the system in late 2021 during its extended mission. In this paper, we incorporate the new TESS photometry into a…

Earth and Planetary Astrophysics · Physics 2022-03-22 Ian Wong , Avi Shporer , Shreyas Vissapragada , Michael Greklek-McKeon , Heather A. Knutson , Joshua N. Winn , Björn Benneke

We re-analyze the pristine eclipsing binary data from the $\textit{Kepler}$ and TESS missions, focusing on eccentricity measurements at short orbital periods to emperically constrain tidal circularization. We find an average circularization…

Solar and Stellar Astrophysics · Physics 2022-05-04 J. J. Zanazzi

This paper investigates the influence of Earth's dipole tilt angle on the reverse convection cells (sometimes referred to as lobe cells) in the Northern Hemisphere ionosphere during northward IMF, which we relate to high-latitude…

Space Physics · Physics 2020-09-16 J. P. Reistad , K. M. Laundal , N. Østeward , A. Ohma , E. G. Thomas , S. Haaland , K. Oksavik , S. E. Milan

SLR technique has being used for determination of ERP during over twenty years. Most of results contributed to IERS are based on analysis of observations of Lageos 1&2 satellites collected at the global tracking network of about 40…

Geophysics · Physics 2011-02-04 Zinovy Malkin

The {\it Kepler} mission revealed a population of compact multiple-planet systems with orbital periods shorter than a year, and occasionally even shorter than a day. By analyzing a sample of 102 {\it Kepler} and {\it K2} multi-planet…

Earth and Planetary Astrophysics · Physics 2018-09-24 Fei Dai , Kento Masuda , Joshua N. Winn

Long-term variations of solar differential rotation and sunspot activity are investigated through re-analyzing the data on parameters of the differential rotation law obtained by Makarov, Tlatov, and Callebaut (1997), Javaraiah, Bertello,…

Solar and Stellar Astrophysics · Physics 2015-06-05 K. J. Li , W. Feng , X. J. Shi , J. L. Xie , P. X. Gao , H. F. Liang