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A. Fienga

Publications and source records attributed to A. Fienga.

At least 19 recordsLinked to original sources
arXiv2023

Constraining massless dilaton theory at Solar system scales with the planetary ephemeris INPOP

We expose the phenomenology of the massless dilaton theory in the Solar system for a non universal quadratic coupling between the scalar field which represents the dilaton, and the matter. Modified post-Newtonian equations of motion of an $N$-body system and the light time travel are derived from the action of the theory. We use the physical properties of the main planets of the Solar system to reduce the number of parameters to be tested to 3 in the linear coupling case. In the linear case, we have an universal coupling constant $\alpha_0$ and two coupling constants $\alpha_T$ and $\alpha_G$ related respectively to the telluric bodies and to the gaseous bodies. We then use the planetary ephemeris, INPOP19a, in order to constrain these constants. We succeeded to constrain the linear coupling scenario and the constraints read $\alpha_0=(1.01\pm23.7)\times 10^{-5}$, $\alpha_T=(0.00\pm24.5)\times 10^{-6}$, $\alpha_G=(-1.46\pm12.0)\times 10^{-5}$, at the 99.5 \% C.L.

gr-qc↗
arXiv2022

INPOP Planetary ephemerides and applications in the frame of the BepiColombo mission including new constraints on the graviton mass and dilaton parameters

We present here the new results obtained with the INPOP planetary ephemerides and BepiColombo radio-science simulations. We give new constraints for the classic General Relativity tests in terms of violation of the PPN parameters $\beta$ and $\gamma$ and the time variation of the gravitational constant G. We also present new limits for the mass of the graviton and finally we obtain new acceptable intervals for the dilaton parameters $\alpha_{0}$, $\alpha_{T}$ and $\alpha_{G}$. Besides these tests of gravitation, we also study the possibility of detecting the Sun core rotation.

gr-qc↗
arXiv2022

Gaia-DR2 asteroid observations and INPOP planetary ephemerides

We used the INPOP19a planetary ephemerides to perform the orbital adjustment of 14099 asteroids based on Gaia-DR2 observations, and compare for 23 of them the resulting orbits to radar data. As Gaia-DR2 has been processed using the planetary ephemeris INPOP10e, the primary goal of this paper is to confirm the portability of the data when using an updated version of the solar system model. In particular, we point out the fact that the Gaia satellite positions -- provided with respect to the INPOP10e solar system barycenter -- must be corrected when using another planetary ephemeris . We also present a convenient least square formalism that only handles small matrices and allows the adjustment of global parameters, such as masses. In order to check the consistency of the Gaia observations with other types of observations, we perform an orbital adjustment in combining Gaia and radar range observations for 23 objects, together with a careful post-fit analysis including an estimation of the Gaia systematic errors. Finally, we show that to ensure the combined use of Gaia angular DR2 observations and radar ranging, a more developed than firstly proposed dynamical modeling is required together with the addition of the systematic Gaia bias in the fit procedure.These results give promising directions for the next Gaia delivery, Gaia-DR3.

astro-ph.EP↗
arXiv2021

Evolution of INPOP planetary ephemerides and Bepi-Colombo simulations

We give here a detailed description of the latest INPOP planetary ephemerides INPOP20a. We test the sensitivity of the Sun oblateness determination obtained with INPOP to different models for the Sun core rotation. We also present new evaluations of possible GRT violations with the PPN parameters $\beta$,$\gamma$ and $\dot{\mu}/\mu$. With a new method for selecting acceptable alternative ephemerides we provide conservative limits of about $7.16 \times 10^{-5}$ and $7.49 \times 10^{-5}$ for $\beta-1$ and $\gamma-1$ respectively using the present day planetary data samples. We also present simulations of Bepi-Colombo range tracking data and their impact on planetary ephemeris construction. We show that the use of future BC range observations should improve these estimates, in particular $\gamma$. Finally, interesting perspectives for the detection of the Sun core rotation seem to be reachable thanks to the BC mission and its accurate range measurements in the GRT frame.

astro-ph.EP↗
arXiv2020

Gaia Early Data Release 3: The astrometric solution

Gaia Early Data Release 3 (Gaia EDR3) contains results for 1.812 billion sources in the magnitude range G = 3 to 21 based on observations collected by the European Space Agency Gaia satellite during the first 34 months of its operational phase. We describe the input data, the models, and the processing used for the astrometric content of Gaia EDR3, as well as the validation of these results performed within the astrometry task. The processing broadly followed the same procedures as for Gaia DR2, but with significant improvements to the modelling of observations. For the first time in the Gaia data processing, colour-dependent calibrations of the line- and point-spread functions have been used for sources with well-determined colours from DR2. In the astrometric processing these sources obtained five-parameter solutions, whereas other sources were processed using a special calibration that allowed a pseudocolour to be estimated as the sixth astrometric parameter. Compared with DR2, the astrometric calibration models have been extended, and the spin-related distortion model includes a self-consistent determination of basic-angle variations, improving the global parallax zero point. Gaia EDR3 gives full astrometric data (positions at epoch J2016.0, parallaxes, and proper motions) for 1.468 billion sources (585 million with five-parameter solutions, 882 million with six parameters), and mean positions at J2016.0 for an additional 344 million. Solutions with five parameters are generally more accurate than six-parameter solutions, and are available for 93% of the sources brighter than G = 17 mag. The median uncertainty in parallax and annual proper motion is 0.02-0.03 mas at magnitude G = 9 to 14, and around 0.5 mas at G = 20. Extensive characterisation of the statistical properties of the solutions is provided, including the estimated angular power spectrum of parallax bias from the quasars.

astro-ph.IM↗
arXiv2020

Constraint on the Yukawa suppression of the Newtonian potential from the planetary ephemeris INPOP19a

We use the latest solution of the ephemeris INPOP (19a) in order to improve our previous constraint on the existence of a Yukawa suppression to the Newtonian potential, generically associated to a graviton's mass. Unlike the ephemeris INPOP17a, several residuals are found to degrade significantly at roughly the same amplitudes of the Compton wavelength $\lambda_g$. As a consequence, we introduce a novel statistical criterion in order to derive the constraint with INPOP19a. After checking that it leads to a constraint consistent with our previous result when applied on INPOP17b, we apply the method to the new solution INPOP19a. We show that the residuals of Mars orbiters, Cassini, Messenger, and Juno, degrade significantly when $\lambda_g \leq$ $3.43 \times 10^{13}$ km with a 99,7% confidence level -- corresponding to a graviton mass bigger than $3.62 \times 10^{-23}$ eV$/c^2$. This is a stronger constraint on the Compton wavelength than the one obtained from the first gravitational-wave transient catalog by the LIGO-Virgo collaboration in the radiative regime, since our 90% C.L. limit reads $\lambda_g >3.93 \times 10^{13}$ km ($m_g <3.16 \times 10^{-23}$ eV$/c^2$).

gr-qc↗
arXiv2019

Constraining the mass of the graviton with the planetary ephemeris INPOP

We use the planetary ephemeris INPOP17b to constrain the mass of the graviton in the Newtonian limit. We also give an interpretation of this result for a specific case of fifth force framework. We find that the residuals for the Cassini spacecraft significantly (90\% C.L.) degrade for Compton wavelengths of the graviton smaller than $1.83\times 10^{13}$ km, corresponding to a graviton mass bigger than $6.76\times 10^{-23} eV/c^2$. This limit is comparable in magnitude to the one obtained by the LIGO-Virgo collaboration in the radiative regime. We also use this specific example to illustrate why constraints on alternative theories of gravity obtained from postfit residuals are generically overestimated.

gr-qc↗
arXiv2019

The homogeneous internal structure of CM-like asteroid (41) Daphne

Context. CM-like asteroids (Ch and Cgh classes) are a major population within the broader C-complex, encompassing about 10% of the mass of the main asteroid belt. Their internal structure has been predicted to be homogeneous, based on their compositional similarity as inferred from spectroscopy (Vernazza et al., 2016, AJ 152, 154) and numerical modeling of their early thermal evolution (Bland & Travis, 2017, Sci. Adv. 3, e1602514). Aims. Here we aim to test this hypothesis by deriving the density of the CM-like asteroid (41) Daphne from detailed modeling of its shape and the orbit of its small satellite. Methods. We observed Daphne and its satellite within our imaging survey with the Very Large Telescope extreme adaptive-optics SPHERE/ZIMPOL camera (ID 199.C-0074, PI P. Vernazza) and complemented this data set with earlier Keck/NIRC2 and VLT/NACO observations. We analyzed the dynamics of the satellite with our Genoid meta-heuristic algorithm. Combining our high-angular resolution images with optical lightcurves and stellar occultations, we determine the spin period, orientation, and 3-D shape, using our ADAM shape modeling algorithm. Results. The satellite orbits Daphne on an equatorial, quasi-circular, prograde orbit, like the satellites of many other large main-belt asteroids. The shape model of Daphne reveals several large flat areas that could be large impact craters. The mass determined from this orbit combined with the volume computed from the shape model implies a density for Daphne of 1.77+/-0.26 g/cm3 (3 {\sigma}). This density is consistent with a primordial CM-like homogeneous internal structure with some level of macroporosity (~17%). Conclusions. Based on our analysis of the density of Daphne and 75 other Ch/Cgh-type asteroids gathered from the literature, we conclude that the primordial internal structure of the CM parent bodies was homogeneous.

astro-ph.EP↗
arXiv2018

Gaia Data Release 2: The astrometric solution

Gaia Data Release 2 (Gaia DR2) contains results for 1693 million sources in the magnitude range 3 to 21 based on observations collected by the European Space Agency Gaia satellite during the first 22 months of its operational phase. We describe the input data, models, and processing used for the astrometric content of Gaia DR2, and the validation of these results performed within the astrometry task. Some 320 billion centroid positions from the pre-processed astrometric CCD observations were used to estimate the five astrometric parameters (positions, parallaxes, and proper motions) for 1332 million sources, and approximate positions at the reference epoch J2015.5 for an additional 361 million mostly faint sources. Special validation solutions were used to characterise the random and systematic errors in parallax and proper motion. For the sources with five-parameter astrometric solutions, the median uncertainty in parallax and position at the reference epoch J2015.5 is about 0.04 mas for bright (G<14 mag) sources, 0.1 mas at G=17 mag, and 0.7 mas at G=20 mag. In the proper motion components the corresponding uncertainties are 0.05, 0.2, and 1.2 mas/yr, respectively. The optical reference frame defined by Gaia DR2 is aligned with ICRS and is non-rotating with respect to the quasars to within 0.15 mas/yr. From the quasars and validation solutions we estimate that systematics in the parallaxes depending on position, magnitude, and colour are generally below 0.1 mas, but the parallaxes are on the whole too small by about 0.03 mas. Significant spatial correlations of up to 0.04 mas in parallax and 0.07 mas/yr in proper motion are seen on small (<1 deg) and intermediate (20 deg) angular scales. Important statistics and information for the users of the Gaia DR2 astrometry are given in the appendices.

astro-ph.IM↗
arXiv2018

Exogenous origin of hydration on asteroid (16) Psyche: The role of hydrated asteroid families

Asteroid (16) Psyche, that for long was the largest M-type with no detection of hydration features in its spectrum, was recently discovered to have a weak 3 micron band and thus it eventually was added to the group of hydrated asteroids. Its relatively high density in combination with the high radar albedo, led to classify the asteroid as a metallic object, possibly a core of a differentiated body, remnant of "hit-and-run" collisions. The detection of hydration is, in principle, inconsistent with a pure metallic origin of this body. Here we consider the scenario that the hydration on its surface is exogenous and was delivered by hydrated impactors. We show that impacting asteroids that belong to families whose members have the 3 m band can deliver the hydrated material to Psyche. We developed a collisional model with which we test all the dark carbonaceous asteroid families, which contain hydrated members. We find that the major source of hydrated impactors is the family of Themis, with a total implanted mass on Psyche to be of the order of 10^14 kg. However, the hydrated fraction could be only a few per cent of the implanted mass, as the water content in carbonaceous chondrite meteorites, the best analogue for the Themis asteroid family, is typically a few per cent of their mass.

astro-ph.EP↗
arXiv2017

The new lunar ephemeris INPOP17a and its application to fundamental physics

We present here the new INPOP lunar ephemeris, INPOP17a. This ephemeris is obtained through the numerical integration of the equations of motion and of rotation of the Moon, fitted over 48 years of Lunar Laser Ranging (LLR) data. We also include the 2 years of infrared (IR) LLR data acquired at the Grasse station between 2015 and 2017. Tests of the universality of free fall are performed. We find no violation of the principle of equivalence at the 10-14 level. A new interpretation in the frame of dilaton theories is also proposed.

gr-qc↗
arXiv2017

Lunar laser ranging in infrfared at hte Grasse laser station

For many years, lunar laser ranging (LLR) observations using a green wavelength have suffered an inhomogeneity problem both temporally and spatially. This paper reports on the implementation of a new infrared detection at the Grasse LLR station and describes how infrared telemetry improves this situation. Our first results show that infrared detection permits us to densify the observations and allows measurements during the new and the full Moon periods. The link budget improvement leads to homogeneous telemetric measurements on each lunar retro-reflector. Finally, a surprising result is obtained on the Lunokhod 2 array which attains the same efficiency as Lunokhod 1 with an infrared laser link, although those two targets exhibit a differential efficiency of six with a green laser link.

astro-ph.IM↗
arXiv2016

Gaia Data Release 1: Astrometry - one billion positions, two million proper motions and parallaxes

Gaia Data Release 1 (Gaia DR1) contains astrometric results for more than 1 billion stars brighter than magnitude 20.7 based on observations collected by the Gaia satellite during the first 14 months of its operational phase. We give a brief overview of the astrometric content of the data release and of the model assumptions, data processing, and validation of the results. For stars in common with the Hipparcos and Tycho-2 catalogues, complete astrometric single-star solutions are obtained by incorporating positional information from the earlier catalogues. For other stars only their positions are obtained by neglecting their proper motions and parallaxes. The results are validated by an analysis of the residuals, through special validation runs, and by comparison with external data. Results. For about two million of the brighter stars (down to magnitude ~11.5) we obtain positions, parallaxes, and proper motions to Hipparcos-type precision or better. For these stars, systematic errors depending e.g. on position and colour are at a level of 0.3 milliarcsecond (mas). For the remaining stars we obtain positions at epoch J2015.0 accurate to ~10 mas. Positions and proper motions are given in a reference frame that is aligned with the International Celestial Reference Frame (ICRF) to better than 0.1 mas at epoch J2015.0, and non-rotating with respect to ICRF to within 0.03 mas/yr. The Hipparcos reference frame is found to rotate with respect to the Gaia DR1 frame at a rate of 0.24 mas/yr. Based on less than a quarter of the nominal mission length and on very provisional and incomplete calibrations, the quality and completeness of the astrometric data in Gaia DR1 are far from what is expected for the final mission products. The results nevertheless represent a huge improvement in the available fundamental stellar data and practical definition of the optical reference frame.

astro-ph.GA↗
arXiv2016

Constraints on the location of a possible 9th planet derived from the Cassini data

To explain the unusual distribution of Kuiper Belt objects, several authors have advocated the existence of a super-Earth planet in the outer solar system. It has recently been proposed that a 10 M$_{\oplus}$ object with an orbit of 700 AU semi major axis and 0.6 eccentricity can explain the observed distribution of Kuiper Belt objects around Sedna. Here we use the INPOP planetary ephemerides model as a sensor for testing for an additional body in the solar system. We test the possibility of adding the proposed planet without increasing the residuals of the planetary ephemerides, fitted over the whole INPOP planetary data sample. We demonstrate that the presence of such an object is not compatible with the most sensitive data set, the Cassini radio ranging data, if its true anomaly is in the intervals $[-130^\circ:-100^\circ]$ or $[-65^\circ : 85^\circ]$. Moreover, we find that the addition of this object can reduce the Cassini residuals, with a most probable position given by a true anomaly $v = {117.8^\circ}^{ + 11^\circ}_{ - 10^\circ} $.

astro-ph.EP↗
arXiv2014

Tests of General relativity with planetary orbits and Monte Carlo simulations

Based on the new developped planetary ephemerides INPOP13c, determinations of acceptable intervals of General Relativity violation in considering simultaneously the PPN parameters $\beta$, PPN $\gamma$, the flattening of the sun $J_{2}^\odot$ and time variation of the gravitational mass of the sun $\mu$ are obtained in using Monte Carlo simulation coupled with basic genetic algorithm. Possible time variations of the gravitational constant G are also deduced. Discussions are lead about the better choice of indicators for the goodness-of-fit for each run and limits consistent with general relativity are obtained simultaneously.

astro-ph.EP↗
arXiv2014

Interests of a new lunar laser instrumentation on the ESO NTT Telescope

We analyze the impact of the installation of a lunar laser ranging device on the NTT 3.6m ESO telescope. With such an instrument, the scientific communities of fundamental physics and solar system formation will highly benefit of the only LLR station in the Southern Hemisphere. The quality of the NTT 3.6 meter telescope will also greatly complement the LLR 3.5 meter Apache Point telescope (3.5 m) instrument in the Northern Hemisphere (USA) which is the best instrument for tracking the Moon since 2006. Finally, we also consider the technical characteristics of such installation including the observational constraints.

astro-ph.IM↗
arXiv2014

INPOP new release: INPOP13b

Based on the use of MESSENGER radiotracking data in the construction of new Mercury ephemerides (Verma et al. 2014) a new planetary ephemerides INPOP13b was built including Mercury improvements but also improvements on the Mars orbit and on the tie of INPOP planetary ephemerides to ICRF in general.

astro-ph.EP↗