- ID:
- ivo://CDS.VizieR/J/ApJ/743/L23
- Title:
- ^48^Ca heterogeneity in differentiated meteorites
- Short Name:
- J/ApJ/743/L23
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Isotopic heterogeneities of ^48^Ca have been found in numerous bulk meteorites that are correlated with ^50^Ti and ^54^Cr anomalies among differentiated planetary bodies, and the results suggest that a rare subset of neutron-rich Type Ia supernova (nSN Ia) was responsible for contributing these neutron-rich iron-group isotopes into the solar system (SS). The heterogeneity of these isotopes found in differentiated meteorites indicates that the isotopic compositions of the bulk SS are not uniform, and there are significant amounts of nSNe Ia dust incompletely mixed with the rest of SS materials during planetary formation. Combined with the data of now-extinct short-lived nuclide ^60^Fe, which can be produced more efficiently from an nSN Ia than a Type II supernova ejecta, the observed planetary-scale isotopic heterogeneity probably reflects a late input of stellar dust grains with neutron-rich nuclear statistical equilibrium nuclides into the early SS.
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- ID:
- ivo://CDS.VizieR/J/AJ/149/27
- Title:
- Cassini ISS astrometry of Saturnian satellites
- Short Name:
- J/AJ/149/27
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present numerically derived orbits and mass estimates for the inner Saturnian satellites, Atlas, Prometheus, Pandora, Janus, and Epimetheus from a fit to 2580 new Cassini Imaging Science Subsystem astrometric observations spanning 2004 February to 2013 August. The observations are provided as machine-readable and Virtual Observatory tables. We estimate GM_Atlas_=(0.384+/-0.001)x10^-3^km^3^/s^2^, a value 13% smaller than the previously published estimate but with an order of magnitude reduction in the uncertainty. We also find GM_Prometheus_=(10.677+/-0.006)x10^-3^km^3^/s^2^, GM_Pandora_=(9.133+/-0.009)x10^-3^km^3^/s^2^, GM_Janus_=(126.51+/-0.03)x10^-3^km^3^/s^2^, and GM_Epimetheus_=(35.110+/-0.009)x10^-3^km^3^/s^2^, consistent with previously published values, but also with significant reductions in uncertainties. We show that Atlas is currently librating in both the 54:53 co-rotation-eccentricity resonance (CER) and the 54:53 inner Lindblad (ILR) resonance with Prometheus, making it the latest example of a coupled CER-ILR system, in common with the Saturnian satellites Anthe, Aegaeon, and Methone, and possibly Neptune's ring arcs. We further demonstrate that Atlas's orbit is chaotic, with a Lyapunov time of ~10years, and show that its chaotic behavior is a direct consequence of the coupled resonant interaction with Prometheus, rather than being an indirect effect of the known chaotic interaction between Prometheus and Pandora. We provide an updated analysis of the second-order resonant perturbations involving Prometheus, Pandora, and Epimetheus based on the new observations, showing that these resonant arguments are librating only when Epimetheus is the innermost of the co-orbital pair, Janus and Epimetheus. We also find evidence that the known chaotic changes in the orbits of Prometheus and Pandora are not confined to times of apse anti-alignment.
- ID:
- ivo://CDS.VizieR/J/A+A/659/A38
- Title:
- Catalogs of potential detections of asteroids
- Short Name:
- J/A+A/659/A38
- Date:
- 02 Mar 2022 07:50:46
- Publisher:
- CDS
- Description:
- The store of data collected in public astronomical archives across the world is continuously expanding and, thus, providing a convenient interface for accessing this information is a major concern for ensuring a second life for the data. In this context, Solar System objects (SSOs) are often difficult or even impossible to query, owing to their ever-changing sky coordinates. Our study is aimed at providing the scientific community with a search service for all potential detections of SSOs among the ESA astronomy archival imaging data, called the Solar System Object Search Service (SSOSS). We illustrate its functionalities using the case of asteroid (16) Psyche, for which no information in the far-IR (70-500 $\mu$m) has previously been reported, to derive its thermal properties in preparation for the upcoming NASA Psyche mission. We performed a geometrical cross-match of the orbital path of each object, as seen by the satellite reference frame, with respect to the public high-level imaging footprints stored in the ESA archives. There are about 800000 asteroids and 2000 comets included in the SSOSS, available through ESASky, providing both targeted and serendipitous observations. For this first release, three missions were chosen: XMM-Newton, the Hubble Space Telescope (HST), and Herschel Observatory. We present a catalog listing all potential detections of asteroids within estimated limiting magnitude or flux limit in Herschel, XMM-Newton, and HST archival imaging data, including 909 serendipitous detections in Herschel images, 985 in XMM-Newton Optical Monitor camera images, and over 32000 potential serendipitous detections in HST images. We also present a case study: the analysis of the thermal properties of Psyche from four serendipitous Herschel detections, combined with previously published thermal IR measurements. We see strong evidence for an unusual drop in (hemispherical spectral) emissivity, from 0.9 at 100um down to about 0.6 at 350um, followed by a possible but not well-constrained increase towards 500um, comparable to what was found for Vesta. The combined thermal data set puts a strong constraint on Psyche's thermal inertia (between 20 to 80J/m^2^/s^1/2^/K) and favors an intermediate to low level surface roughness (below 0.4 for the rms of surface slopes). Conclusions: Using the example of Psyche, we show how the SSOSS provides fast access to observations of SSOs from the ESA astronomical archives, regardless of whether the particular object was the actual target. This greatly simplifies the task of searching, identifying, and retrieving such data for scientific analysis.
- ID:
- ivo://CDS.VizieR/VI/140
- Title:
- Catalogue of Lunar Eclipse Crater Timings
- Short Name:
- VI/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue contains lunar eclipse crater timing observations made during 94 lunar eclipses in the period 1842 and 2011, together with a reduction of each observation.
- ID:
- ivo://CDS.VizieR/J/A+A/391/767
- Title:
- CCD observations of Phoebe in 1998-1999
- Short Name:
- J/A+A/391/767
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In 1998 and 1999, we started observations of the 9th satellite of Saturn. We made 163 observations using the 120cm-telescope of Observatoire de Haute-Provence, France. We used the USNO A2 catalogue (Cat. <I/252>) of stars for the astrometric reduction. With the help of observations of optical counterparts of ICRF sources, a zonal correction to the USNO A2.0 catalogue was computed and applied to the Phoebe positions. A comparison to the most recent theories was made.
- ID:
- ivo://CDS.VizieR/J/other/SoSyR/45.523
- Title:
- CCD observations of saturnian satellites
- Short Name:
- J/other/SoSyR/45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The astrometric positions of seven saturnian satellites are presented. Positions were derived from more then 5000 CCD frames taken with 26-inch Zeiss refractor at Pulkovo from Jan 2008 to may 2009. Astrometric reduction algorithm is based on Turner's method with using UCAC2 catalog as reference one. Observed positions were compared with theoretical ones from TASS 1.7 (Viennel & Duriez, 1995A&A...297..588V). The accuracy is about 0.05 arcsec. Also positions of Saturn were obtained from observations of satellites 2-6.
- ID:
- ivo://CDS.VizieR/J/A+A/453/349
- Title:
- CCD positions for eight Jovian irregular satellites
- Short Name:
- J/A+A/453/349
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The astrometric positions of eight irregular Jovian satellites are given for the oppositions of the planet from 1995 to 1999. These positions were measured on 204 CCD frames obtained at the Cassegrain focus of a 1.6m reflector. They are compared with the theoretically calculated positions from JPL Development Ephemeris. The observed minus-calculated standard deviation for all observations of the eight satellites are {sigma}_RA_=0.071" and {sigma}_DE_=0.052". The USNO-A2.0 (<I/252>) catalog was used for the astrometric calibration.
- ID:
- ivo://CDS.VizieR/J/A+A/636/A45
- Title:
- CEGM03 model and related gravity anomaly data
- Short Name:
- J/A+A/636/A45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Chinese lunar missions have grown in number over the last ten years, with an increasing focus on radio science investigations. In previous work, we estimated two lunar gravity field models, CEGM01 and CEGM02. The recently lunar mission, Chang'e 5T1, which had an orbital inclination between 18 and 68 degree, and collected orbital tracking data continually for two years, made an improved gravity field model possible. We aimed to estimate a new lunar gravity field model up to degree and order 100, CEGM03, and a new tidal Love number based on the Chang'e 5T1 tracking data combined with the historical tracking data ever used in the solution of CEGM02. The new model makes use of tracking data with this particular inclination, which has not been used in previous gravity field modeling. The solution for this new model was based on our in-house software, LUGREAS. The gravity spectrum power, postfit residuals after precision orbit determination (POD), lunar surface gravity anomalies, correlations between parameters, admittance/coherence with topography model, and accuracy of POD were analyzed to validate the new CEGM03 model. We analyzed the tracking data of the Chang'e 5T1 mission and estimated the CEGM03 lunar gravity field model. We found that the two-way Doppler measurement accuracy reached the 0.2 mm/s with 10 s integration time. The error spectrum shows that the formal error for CEGM03 was at least reduced by about 2 times below the harmonic degree of 20, when compared to the CEGM02 model. The gravity and topography admittance/correlation was also improved when compared to the correlations for the CEGM02 model. The lunar potential Love number k2 was estimated to be 0.02430+/-0.0001 (ten times the formal error). From the model analysis and comparison of the various models, we identified improvements in the CEGM03 model after introducing Chang'e 5T1 tracking data. Moreover, this study illustrates how the low and middle inclination orbits could contribute better accuracy for a low degree of lunar gravity field.
- ID:
- ivo://CDS.VizieR/J/A+A/654/A156
- Title:
- Chaotic diffusion of fundamental frequencies
- Short Name:
- J/A+A/654/A156
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The long-term variations of the orbit of the Earth govern the insolation on its surface and hence its climate. The use of the astronomical signal, whose imprint has been recovered in the geological records, has revolutionized the determination of the geological time scales (e.g. Gradstein & Ogg, 2020, in Geologic Time Scale (Amsterdam: Elsevier), 21). However, the orbital variations beyond 60Myr cannot be reliably predicted because of the A,chaotic dynamics of the planetary orbits in the Solar System (Laskar, 1989Natur.338..237L). Taking into account this dynamical uncertainty is necessary for a complete astronomical calibration of geological records. Our work addresses this problem with a statistical analysis on 120000 orbital solutions of the secular model of the Solar System ranging from 500Myr to 5Gyr. We obtain the marginal probability density functions of the fundamental secular frequencies using kernel density estimation. The uncertainty of the density estimation is also obtained here in the form of confidence intervals determined by the moving block bootstrap method. The results of the secular model are shown to be in good agreement with those of the direct integrations of a comprehensive model of the Solar System. Applicationof our work is illustrated on two geological data: the Newark-Hartford
- ID:
- ivo://CDS.VizieR/J/A+A/652/A141
- Title:
- Chariklo's system from stellar occultations
- Short Name:
- J/A+A/652/A141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Centaur (10199) Chariklo has the first rings system discovered around a small object. It was first observed using stellar occultation in 2013. Stellar occultations allow the determination of sizes and shapes with kilometre accuracy and obtain characteristics of the occulting object and its vicinity. Using stellar occultations observed between 2017 and 2020, we aim at constraining Chariklo's and its rings physical parameters. We also determine the rings' structure, and obtain precise astrometrical positions of Chariklo. We predicted and organised several observational campaigns of stellar occultations by Chariklo. Occultation light curves were measured from the data sets, from which ingress and egress times, and rings' width and opacity were obtained. These measurements, combined with results from previous works, allow us to obtain significant constraints on Chariklo's shape and rings' structure. We characterise Chariklo's ring system (C1R and C2R), and obtain radii and pole orientations that are consistent with, but more accurate than, results from previous occultations. We confirmed the detection of W-shaped structures within C1R and an evident variation of radial width. The observed width ranges between 4.8 and 9.1km with a mean value of 6.5km. One dual observation (visible and red) does not reveal any differences in the C1R opacity profiles, indicating ring particle's size larger than a few microns. The C1R ring eccentricity is found to be smaller than 0.022 (3-sigma), and its width variations may indicate an eccentricity higher than 0.005. We fit a tri-axial shape to Chariklo's detections over eleven occultations and determine that Chariklo is consistent with an ellipsoid with semi-axes of 143.8, 135.2 and 99.1km. Ultimately, we provided seven astrometric positions at a milliarcseconds accuracy level, based on Gaia EDR3, and use it to improve Chariklo's ephemeris.
