165 citations · 611 across the 13 of their papers we have counts for
13 papers
The precious set of radio-optical reference frame objects in the light of Gaia DR2 data
Valeri V. Makarov, Ciprian T. Berghea, Julien Frouard +2
We investigate a sample of 3412 {\it International Celestial Reference Frame} (ICRF3) extragalactic radio-loud sources with accurate positions determined by VLBI in the S/X band, m…
Towards the ICRF3: astrometric comparison of the USNO 2016A VLBI solution with ICRF2 and Gaia DR1
Julien Frouard, Megan C. Johnson, Alan Fey +2
The VLBI USNO 2016A (U16A) solution is part of a work-in-progress effort by USNO towards the preparation of the ICRF3. Most of the astrometric improvement with respect to the ICRF2…
Double stars and astrometric uncertainties in Gaia DR1
Valeri V. Makarov, Claus Fabricius, Julien Frouard
A significant number of double stars with separations up to 2.5 arcsec are present in the Gaia Data Release 1 astrometric catalogs. Limiting our analysis to a well-studied sample o…
UCAC5: New Proper Motions using Gaia DR1
Norbert Zacharias, Charlie Finch, Julien Frouard
New astrometric reductions of the US Naval Observatory CCD Astrograph Catalog (UCAC) all-sky observations were performed from first principles using the TGAS stars in the 8 to 11 m…
Tides in a body librating about a spin-orbit resonance. Generalisation of the Darwin-Kaula theory
Julien Frouard, Michael Efroimsky
The Darwin-Kaula theory of bodily tides is intended for celestial bodies rotating without libration. We demonstrate that this theory, in its customary form, is inapplicable to a li…
Astrometric evidence for a population of dislodged AGN
Valeri V. Makarov, Julien Frouard, Ciprian T. Berghea +5
We investigate a sample of 2293 ICRF2 extragalactic radio-loud sources with accurate positions determined by VLBI, mostly active galactic nuclei (AGN) and quasars, which are cross-…
Tidal spin down rates of homogeneous triaxial viscoelastic bodies
Alice C. Quillen, Andrea Kueter-Young, Julien Frouard +1
We use numerical simulations to measure the sensitivity of the tidal spin down rate of a homogeneous triaxial ellipsoid to its axis ratios by comparing the drift rate in orbital se…
Precession Relaxation of Viscoelastic Oblate Rotators
Julien Frouard, Michael Efroimsky
Perturbations of all sorts destabilise the rotation of a small body and leave it in a non-principal spin state. In such a state, the body experiences alternating stresses generated…
Numerical Simulation of Tidal Evolution of a Viscoelastic Body Modelled with a Mass-Spring Network
Julien Frouard, Alice C. Quillen, Michael Efroimsky +1
We use a damped mass-spring model within an N-body code to simulate the tidal evolution of the spin and orbit of a self-gravitating viscoelastic spherical body moving around a poin…
Forced libration of tidally synchronized planets and moons
Valeri V. Makarov, Julien Frouard, Bryan Dorland
Tidal dissipation of kinetic energy, when it is strong enough, tends to synchronize the rotation of planets and moons with the mean orbital motion, or drive it into long-term stabl…
Identification of 1.4 Million AGNs in the Mid-Infrared using WISE Data
Nathan Secrest, Rachel Dudik, Bryan Dorland +5
We present an all-sky sample of ~ 1.4 million AGNs meeting a two color infrared photometric selection criteria for AGNs as applied to sources from the Wide-Field Infrared Survey Ex…
Spin-orbit evolution of Mercury revisited
Benoit Noyelles, Julien Frouard, Valeri Makarov +1
While it is accepted that the eccentricity of Mercury (0.206) favours entrapment into the 3:2 spin-orbit resonance, open is the question how and when the capture took place. A rece…
Instability zones for satellites of asteroids. The example of the (87) Sylvia system
Julien Frouard, Audrey Compère
We study the stability of the (87) Sylvia system and of the neighborhood of its two satellites. We use numerical integrations considering the non-sphericity of Sylvia, as well as t…