Статті в журналах: "Planetary ephemerides"

1

Standish, E. M. "The Dynamical Reference Frame." Symposium - International Astronomical Union 166 (1995): 109–16. http://dx.doi.org/10.1017/s0074180900227939.

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Planetary and lunar ephemerides continue to improve in accuracy as they continue to be adjusted to newer and more accurate observational data. An additional improvement will be that of the orientation of the ephemerides; in the future, the ephemerides produced at JPL will be based upon the reference frame of the radio source catalogues. Recent planetary observations have been made directly with respect to the radio reference frame, and these observations have shown a satisfying degree of absolute accuracy and internal consistency; they enable the automatic orientation of the ephemerides onto the radio reference system during the ephemeris adjustment process.

2

Fukushima, Toshio, George H. Kaplan, George A. Krasinsky, Jean Eudes Arlot, John A. Bangert, Catherine Y. Hohenkerk, George A. Krasinsky, et al. "COMMISSION 4: EPHEMERIDES." Proceedings of the International Astronomical Union 4, T27A (December 2008): 5–11. http://dx.doi.org/10.1017/s1743921308025234.

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JPL planetary ephemeris development has been very active assimilating measurements from current planetary missions and supporting future missions. The NASA Mars Science Laboratory (MSL) mission with launch in 2009 requires knowledge of the Earth and Mars ephemerides with 30m accuracy. By comparison, the accuracy of the Mars ephemeris in the widely used DE405 ephemeris was about 3 km. Meeting the MSL needs requires an ongoing program of range and very-long baseline interferometry measurements of Mars orbiting spacecraft. The JPL ephemeris DE421 was released three months before the landing of the Phoenix mission on Mars, and has met the 300m requirement. Continued measurements are planned to support the MSL landing.

3

Standish, E. Myles. "Numerical planetary and lunar ephemerides: present status, precision and accuracies." Symposium - International Astronomical Union 114 (1986): 71–83. http://dx.doi.org/10.1017/s0074180900148016.

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The Ephemeris Development Program has been in existence for nearly 20 years at JPL, providing high precision present-day knowledge of the positions of the moon and major planets. The resultant ephemerides are used extensively in the navigation of spacecraft and in the reduction of astrometric observations. They also provide a key element in the testing of various theories of gravitation and a means for the determination of various relevant astronomical constants. The ephemerides and the process of creating them are both shown to be viable tools for the measurement of various gravitational effects which govern the motions of the objects in the solar system.This paper gives an outline of the least-squares adjustment of the ephemerides to the observations, the present physical (dynamical) model, the present observations to which the ephemerides are fit, the expected accuracies of various ephemeris elements, recent and future observations and features of the solar system which are poorly determined (and thereby place limits upon the accuracies). Recent comparisons with similar work at the Center for Astrophysics (formerly at MIT) are serving as valuable independent checks on formulations and procedures used at each institution; they also lend insight toward what are the realistic accuracies being attained. The export procedure, by which an outside user may obtain and use the JPL ephemerides, is described.

4

Krasinsky, George, Toshio Fukushima, J. Chapront, E. M. Standish, C. Hohenkerk, G. Kaplan, P. K. Seidelmann, J. Bangert, S. Urban, and J. Vondrak. "Commission 4: Ephemerides." Proceedings of the International Astronomical Union 1, T26A (December 2005): 3–6. http://dx.doi.org/10.1017/s1743921306004285.

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JPL continues to be active in creating ephemerides in support of spacecraft navigation as well as various other functions. Many of the products are available on web sites: (a) “Horizons”, the interactive web site, updated on an hourly basis, is located at http://ssd.jpl.nasa.gov. As of August, 2005, it contains orbital elements and ephemerides for the sun and 9 planets, 150 natural satellites (including the Moon), 291, 655 asteroids, 1631 comets, and 34 Spacecraft. Horizons uses the full precision of the JPL DE405.(b)JPL's Planetary and Lunar Ephemerides in “export” format are available via FTP from the Internet: ftp://ssd.jpl.nasa.gov/pub/eph/export/ or on a CD-ROM: http://www.willbell.com/software/jpl.htm We advise to read the attached README.(c)The observational data used in fitting the planetary ephemerides is available at the following web site, updated periodically: http://ssd.jpl.nasa.gov/plan-eph-data/(d)SPICE Toolkit is a subroutine package for experienced programmers who write their own main driving programs for astrometrical computations. SPICE is available at http://naif.jpl.nasa.gov/. It contains a large library of subroutines useful in reading SPICE format ephemeris files (SPK) and in computing many solar system observation geometry parameters associated with the various JPL solar system missions. Available in Fortran, C, and IDL for most popular computing platforms.

5

Pang, Kevin D., and Kevin K. Yau. "The need for more accurate 4000-year ephemerides, based on lunar and spacecraft ranging, ancient eclipse and planetary data." Symposium - International Astronomical Union 172 (1996): 113–16. http://dx.doi.org/10.1017/s0074180900127202.

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Long planetary and lunar ephemerides like the JPL DE102 and LE51 (Newhall et al., 1983) and the Bureau des Longitudes VSOP (Bretagnon, 1982) and ELP (Chapront-Touze and Chapront, 1983) have enabled more positive ancient eclipse, planetary and cometary identifications, which have in turn refined ephemerides, e.g., the reconstruction of the orbit of comets Halley and Swift-Tuttle (Yeomans and Kiang, 1981; and Yau et al., 1994). The data used to initialize DE102 are pre-1977. Much more observational data have been collected since. The lunar ephemeris has also been improved. The secular lunar acceleration, , from laser ranging, is −25.9±0.5″/cen2 (Williams et al., 1992). We can now uniquely solve for ΔT, the clock error, from ancient eclipse records. The lack of ΔT values before 700 B.C. has left the early timescale of the ephemerides unconstrained (Morrison, 1992). Our solution of this problem is outlined here.

6

Tang, K., Y. Z. Song, K. X. Shen, R. C. Qiao, Z. H. Tang, Y. Yu, H. Y. Zhang, and D. Yan. "The orbit of Triton with new precise observations and the INPOP19a ephemeris." Astronomy & Astrophysics 641 (September 2020): A108. http://dx.doi.org/10.1051/0004-6361/202038556.

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Aims. The Gaia catalogue brings new opportunities and challenges to high-precision astronomy and astrometry. The precision of data reduction is therefore improved by a large number of reference stars with high-precision positions and proper motions. Numerous precise positions for Triton are obtained from the latest observations using the Gaia catalogue. Furthermore, the new INPOP19a planetary ephemeris, which also fits the observations from the Gaia Data Release 2, has recently become available. In this paper, a new orbit of Triton is calculated using the latest precise charge-coupled device (CCD) observations and the INPOP19a ephemeris. Methods. Triton’s orbital solution is calculated using a numerical integrator, while the orientation of Neptune’s pole in particular is obtained by integrating the simplified Euler’s equations of motion. We determine the orbit of Triton over 170 yr based on 11 040 Earth-based observations made between 1847 and 2016 and on Voyager 2 data. The positions of the Sun and planets are provided by the INPOP19a ephemeris. We compare our results to those from other previous works to check the influences on Triton’s orbit from different planetary ephemerides. Results. A new orbit of Triton is provided here. The root-mean-square of the residuals for the Earth-based CCD absolute observations are 0.102″ in right ascension and 0.142″ in declination. Although most different planetary ephemerides have large differences in Neptune’s position, the orbits of Triton using different planetary ephemerides are still close, under similar dynamical models. The Voyager 2 data add a constraint on Triton’s orbit here.

7

Standish, E. M. "Celestial Reference Frames: Definitions and Accuracies." Symposium - International Astronomical Union 129 (1988): 309–15. http://dx.doi.org/10.1017/s0074180900134813.

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The determination of a specific catalogue or ephemeris reference frame is a highly over-determined problem, depending on the particular selection of which coordinates, which objects and at what time(s) the determination is made. The consistency which various determinations exhibit is dependent upon the accuracy of the catalogue or ephemeris itself. This paper discusses the accuracies of the three most prominent celestial reference frames: stellar catalogues, the lunar and planetary ephemerides and the radio source catalogues.The FK4 stellar catalogue contains known systematic errors amounting to a few tenths of an arcsecond; the FK5 will yield nearly an order of magnitude improvement; HIPPARCOS and Space Telescope expectby the mid 1990's optical interferometry should approachwithin a couple of years, tens of micro(!)arcseconds after a couple of decades. Present-day lunar and planetary ephemerides have accuracies at the level offor the moon and inner four planets;for the outer planets. Further observational data will permit continued improvement. Radio source catalogues now show internal consistency of

8

Capistrano, Abraão J. S., Joice A. M. Penagos, and Manuel S. Alárcon. "Heuristic Approach on Anomalous Apsidal Precession of Planets." International Journal of Modern Physics: Conference Series 45 (January 2017): 1760074. http://dx.doi.org/10.1142/s2010194517600746.

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In this paper we study the anomalous movement of planet precession as compared with different observational data from Ephemerides of the Planets and the Moon (EPM2008 and EPM2011) and the Planetary and Lunar Ephemeris (INPOP10a). Using a heuristic methodology we obtain a very close results to observations.

9

Standish, E. M., and X. X. Newhall. "New accuracy levels for solar system ephemerides." Symposium - International Astronomical Union 172 (1996): 29–36. http://dx.doi.org/10.1017/s0074180900127081.

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DE403/LE403 is the latest JPL Planetary and Lunar Ephemeris. It represents a number of changes and improvements to previous JPL ephemerides: the reference frame is now that of the IERS, newer and more accurate observations are used in the adjustment process, some of the data reduction techniques have been refined, and improved dynamical modeling has been incorporated into the equations of motion. As a result, the internal accuracy of the inner four planets has been improved. Further, various measurements accurately tie Jupiter onto the IERS Reference Frame. In the future, use of CCD measurements and the Hipparcos Catalogue should improve the ephemerides of the outermost four planets.DE403/LE403 has been integrated over 6000 years, from 3000 BC to 3000 AD. A more condensed representation has been made from this, named DE404/LE404. It replaces DE102 as the new JPL “Long Ephemeris”.

10

Coma, J. C., M. Lara, and T. López Moratalla. "Uniform approximation of planetary ephemerides." Astronomy and Astrophysics Supplement Series 129, no. 2 (April 1998): 425–30. http://dx.doi.org/10.1051/aas:1998194.

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11

Newhall, X. X. "Numerical representation of planetary ephemerides." Celestial Mechanics 45, no. 1-3 (March 1988): 305–10. http://dx.doi.org/10.1007/bf01229014.

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12

Kammeyer, Peter. "Compressed planetary and lunar ephemerides." Celestial Mechanics 45, no. 1-3 (March 1988): 311–16. http://dx.doi.org/10.1007/bf01229015.

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13

Standish, E. M. "Fundamental Arguments of the Current Nutation Theory: Dynamical Reference Frame." Highlights of Astronomy 11, no. 1 (1998): 168. http://dx.doi.org/10.1017/s1539299600020347.

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The latest JPL planetary and lunar ephemerides, DE405, are now referenced to the ICRF with an accuracy of about 1 mas. This has been accomplished mainly by fitting the ephemerides to 18 VLBI observations of the Magellan Spacecraft in orbit around Venus, 1990-1994, and to 2 VLBI observations of the Phobos Spacecraft in its approach to Mars, 1989. The orientation of DE405 is discussed in more detail elsewhere in this volume (Standish, 1997). Since all of the parameters of the inner solar system are now determined to 1 mas or better, one should be able to extract numerically the fundamental arguments of the nutation theories to the level of 1 mas.There are two ways of extracting the ecliptic, for example, from a numerical ephemeris: 1) one computes the node and obliquity of the instantaneous ecliptic at multiple points in time and then fits these with analytic functions, or 2) one fits an analytical planetary theory to the ephemerides and then computes the node and obliquity from the theory’s parameters. This paper relates a short example using method #1 and concludes that method #2 is probably more preferable.

14

Xi, X. J., and A. Vienne. "Analytical representation for ephemeride with short time spans." Astronomy & Astrophysics 635 (March 2020): A91. http://dx.doi.org/10.1051/0004-6361/201937148.

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Context. The ephemerides of natural satellites resulting from numerical integration have a very good precision on the fitting to recent observations, in a limited interval. Meanwhile, synthetic ephemerides like the Théorie Analytique des Satellites de Saturne (TASS) by Vienne and Duriez describe in detail the dynamical system by a representation based on the combinations of the proper frequencies. Some theoretical studies need to have both advantages. For example, to study the rotation of Titan, one needs to know the representation of its longitude. Aims. We aim to use these two types of ephemerides in order to rebuild a long-lasting and high-precision ephemeris with proper frequencies based on the numerical integration ephemeris. The aim is to describe the numerical ephemerides with formulas similar to analytical ones. Methods. We used the representation of the orbital elements from the TASS ephemeris analysed over 10 000 years as a reference template. We obtained the proper frequencies with both numerical and the TASS ephemeris over 1000 years only. A least-square procedure allowed us to get the analytical representation of an orbital element in this limited interval. Results. We acquire the representation of the mean longitude of Titan from JPL ephemeris over 1000 years. For almost all components, the corresponding amplitudes and phases are similar to the relative terms from TASS. The biggest difference between our representation and the mean longitude of Titan of JPL is less than 100 km over 1000 years, and the standard deviation is about 26 km.

15

Coma, J. C., M. Lara, and T. J. López Moratalla. "Fast evaluation of ephemerides by polynomial approximation in the Chebyshev norm." Symposium - International Astronomical Union 172 (1996): 345–46. http://dx.doi.org/10.1017/s0074180900127640.

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Normally the planetary and satellite ephemerides are provided in tabular form, where the user interpolates between points in order to obtain the ephemerides. There are other methods of providing ephemerides by means of polynomial representations. The user is supplied with the coefficients of a set of polynomials which allow him a fast ephemerides evaluation.

16

Di Ruscio, A., A. Fienga, D. Durante, L. Iess, J. Laskar, and M. Gastineau. "Analysis of Cassini radio tracking data for the construction of INPOP19a: A new estimate of the Kuiper belt mass." Astronomy & Astrophysics 640 (July 28, 2020): A7. http://dx.doi.org/10.1051/0004-6361/202037920.

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Context. Recent discoveries of new trans-Neptunian objects have greatly increased the attention by the scientific community to this relatively unknown region of the solar system. The current level of precision achieved in the description of planet orbits has transformed modern ephemerides in the most updated tools for studying the gravitational interactions between solar system bodies. In this context, the orbit of Saturn plays a primary role, especially thanks to Cassini tracking data collected during its 13-year mission around the ringed planet. Planetary ephemerides are currently mainly built using radio data, in particular with normal points derived from range and Doppler observables exchanged between ground stations and interplanetary probes. Aims. We present an analysis of Cassini navigation data aimed at producing new normal points based on the most updated knowledge of the Saturnian system developed throughout the whole mission. We provide additional points from radio science dedicated passes of Grand Finale orbits and Titan flybys. An updated version of the INPOP planetary ephemerides based upon these normal points is presented, along with a new estimate of the mass of trans-Neptunian object rings located in the 2:1 and 3:2 mean motion resonances with Neptune. Methods. We describe in detail the orbit determination process performed to construct the normal points and their associated uncertainties and how we process those points to produce a new planetary ephemeris. Results. From the analysis, we obtained 623 new normal points for Saturn with metre-level accuracy. The ephemeris INPOP19a, including this new dataset, provides an estimated mass for the trans-Neptunian object rings of (0.061 ± 0.001)M⊕.

17

Fienga, A., A. Di Ruscio, L. Bernus, P. Deram, D. Durante, J. Laskar, and L. Iess. "New constraints on the location of P9 obtained with the INPOP19a planetary ephemeris." Astronomy & Astrophysics 640 (July 28, 2020): A6. http://dx.doi.org/10.1051/0004-6361/202037919.

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Context. We used the new released INPOP19a planetary ephemerides benefiting from Jupiter-updated positions by the Juno mission and reanalyzed Cassini observations. Aims. We test possible locations of the unknown planet P9. To do this, we used the perturbations it produces on the orbits of the outer planets, more specifically, on the orbit of Saturn. Methods. Two statistical criteria were used to identify possible acceptable locations of P9 according to (i) the difference in planetary positions when P9 is included compared with the propagated covariance matrix, and (ii) the χ2 likelihood of postfit residuals for ephemerides when P9 is included. Results. No significant improvement of the residuals was found for any of the simulated locations, but we provide zones that induce a significant degradation of the ephemerides. Conclusions. Based on the INPOP19a planetary ephemerides, we demonstrate that if P9 exists, it cannot be closer than 500 AU with a 5 M⊕ and no closer than 650 AU with a 10 M⊕. We also show that there is no clear zone that would indicate the positive existence of planet P9, but there are zones for which the existence of P9 is compatible with the 3σ accuracy of the INPOP planetary ephemerides.

18

Folkner, W. M. "Relativistic aspects of the JPL planetary ephemeris." Proceedings of the International Astronomical Union 5, S261 (April 2009): 155–58. http://dx.doi.org/10.1017/s1743921309990329.

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AbstractThe orbits of the planets as represented by the JPL planetary ephemerides are now primarily determined by radio tracking of spacecraft. Analysis of the data and propagation of the orbits relies on an internally consistent set of equations of motion and propagation of radio signals including relativistic effects at the centimeter level. The planetary ephemeris data set can be used to test some aspects of the underlying theory such as estimates of PPN parameters γ and β, time variation in the gravitational constant G, rotation of the solar system relative to distant objects (Mach's principle), and place stringent limits on the possible violation of the inverse-square law.

19

Cionco, Rodolfo G., and Dmitry A. Pavlov. "Solar barycentric dynamics from a new solar-planetary ephemeris." Astronomy & Astrophysics 615 (July 2018): A153. http://dx.doi.org/10.1051/0004-6361/201732349.

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Aims. The barycentric dynamics of the Sun has increasingly been attracting the attention of researchers from several fields, due to the idea that interactions between the Sun’s orbital motion and solar internal functioning could be possible. Existing high-precision ephemerides that have been used for that purpose do not include the effects of trans-Neptunian bodies, which cause a significant offset in the definition of the solar system’s barycentre. In addition, the majority of the dynamical parameters of the solar barycentric orbit are not routinely calculated according to these ephemerides or are not publicly available. Methods. We developed a special version of the IAA RAS lunar–solar–planetary ephemerides, EPM2017H, to cover the whole Holocene and 1 kyr into the future. We studied the basic and derived (e.g., orbital torque) barycentric dynamical quantities of the Sun for that time span. A harmonic analysis (which involves an application of VSOP2013 and TOP2013 planetary theories) was performed on these parameters to obtain a physics-based interpretation of the main periodicities present in the solar barycentric movement. Results. We present a high-precision solar barycentric orbit and derived dynamical parameters (using the solar system’s invariable plane as the reference plane), widely accessible for the whole Holocene and 1 kyr in the future. Several particularities and barycentric phenomena are presented and explained on dynamical bases. A comparison with the Jet Propulsion Laboratory DE431 ephemeris, whose main differences arise from the modelling of trans-Neptunian bodies, shows significant discrepancies in several parameters (i.e., not only limited to angular elements) related to the solar barycentric dynamics. In addition, we identify the main periodicities of the Sun’s barycentric movement and the main giant planets perturbations related to them.

20

Standish, E. M., X. X. Newhall, J. G. Williams, and J. O. Dickey. "The reference frame of the ephemerides." Symposium - International Astronomical Union 128 (1988): 49–53. http://dx.doi.org/10.1017/s0074180900119254.

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Complete ephemerides of the moon and the four inner planets could be created solely from ranging data alone. Such ephemerides would then be independent from any outside astronomical reference system, and, therefore, would define their own unique reference frame. In fact, this is nearly the case with present-day ephemerides; the accuracy of the ranging data tends to dominate most of the least squares adjustment.This paper outlines the process of creating the lunar and planetary ephemerides along with the orientation of the ephemerides onto the dynamical equinox. The resulting accuracies of these processes are given and a number of uses for the ephemerides are highlighted.

21

Fienga, A. "How GAIA can improve planetary ephemerides?" Planetary and Space Science 73, no. 1 (December 2012): 44–46. http://dx.doi.org/10.1016/j.pss.2012.06.016.

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22

Fienga, A., J. Laskar, P. Kuchynka, C. Leponcin-Lafitte, H. Manche, and M. Gastineau. "Gravity tests with INPOP planetary ephemerides." Proceedings of the International Astronomical Union 5, S261 (April 2009): 159–69. http://dx.doi.org/10.1017/s1743921309990330.

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AbstractWe present here several gravity tests made with the latest INPOP08 planetary ephemerides. We first propose two methods to estimate the PPN parameter β and its correlated value, the Sun J2, and we discuss the correlation between the Sun J2 and the mass of the asteroid ring. We estimate a possible advance in the planet perihelia. We also show that no constant acceleration larger than 1/4 of the Pioneer anomaly is compatible with the observed motion of the planets in our Solar System.

23

Standish, E. M. "Linking the Dynamical Reference frame to the ICRF." Highlights of Astronomy 11, no. 1 (1998): 310–12. http://dx.doi.org/10.1017/s1539299600020839.

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AbstractThe latest JPL planetary and lunar ephemerides, DE405, are referenced to the International Celestial Reference Frame (ICRF) with an accuracy that approaches 1 mas for the four innermost planets, the sun, and the moon. This has been accomplished mainly by 18 VLBI observations of the Magellan Spacecraft in orbit around Venus. The ephemeris of Jupiter, however, is not well-determined since the various observations are not consistent within each other. The outer four planets continue to rely almost entirely upon optical observations; their ephemeris uncertainties lie in the 100-200 mas range.

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Belikov, M. L., V. N. Boyko, N. I. Glebova, G. I. Eroshkin, L. I. Rumyantseva, M. L. Sveshnikov, E. S. Sveshnikova, et al. "The Main Stages of the Construction of AE89—The Numerical Ephemeris of the Planets and the Moon." Symposium - International Astronomical Union 141 (1990): 183–85. http://dx.doi.org/10.1017/s0074180900086733.

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The realization of theoretical and applied researches in the domain of ephemeris astronomy, connected with analysis of precision of existing planetary and lunar theories, the construction of an inertial coordinate system and investigation of physical properties of space-time, necessitated the elaboration in ITA of the numerical theory of the motion of heavenly bodies suitable for calculation of high-precision ephemerides at large time-spans, and fit also for the maintenance of space experiments.

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Standish, E. Myles, and James G. Williams. "Models for high-precision spacecraft and planetary and lunar ephemerides." Proceedings of the International Astronomical Union 2, no. 14 (August 2006): 468. http://dx.doi.org/10.1017/s174392130701143x.

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Qiao, Jing, Wu Chen, Shengyue Ji, and Duojie Weng. "Accurate and Rapid Broadcast Ephemerides for Beidou-Maneuvered Satellites." Remote Sensing 11, no. 7 (April 2, 2019): 787. http://dx.doi.org/10.3390/rs11070787.

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The geostationary earth orbit (GEO) and inclined geosynchronous orbit (IGSO) satellites of the Beidou navigation satellite system are maneuvered frequently. The broadcast ephemeris can be interrupted for several hours after the maneuver. The orbit-only signal-in-space ranging errors (SISREs) of broadcast ephemerides available after the interruption are over two times larger than the errors during normal periods. To shorten the interruption period and improve the ephemeris accuracy, we propose a two-step orbit recovery strategy based on a piecewise linear thrust model. The turning points of the thrust model are firstly determined by comparison of the kinematic orbit with an integrated orbit free from maneuver; afterward, precise orbit determination (POD) is conducted for the maneuvered satellite by estimating satellite orbital and thrust parameters simultaneously. The observations from the IGS Multi-Global Navigation Satellite System (GNSS) Experiment (MGEX) network and ultra-rapid products of the German Research Center for Geosciences (GFZ) are used for orbit determination of maneuvered satellites from Sep to Nov 2017. The results show that for the rapidly recovered ephemerides, the average orbit-only SISREs are 1.15 and 1.0 m 1 h after maneuvering for GEO and IGSO respectively, which is comparable to the accuracy of Beidou broadcast ephemerides in normal cases.

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Battley, Matthew P., Michelle Kunimoto, David J. Armstrong, and Don Pollacco. "Revisiting theKeplerfield withTESS: Improved ephemerides usingTESS2 min data." Monthly Notices of the Royal Astronomical Society 503, no. 3 (March 10, 2021): 4092–104. http://dx.doi.org/10.1093/mnras/stab701.

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ABSTRACTUp to date planet ephemerides are becoming increasingly important as exoplanet science moves from detecting exoplanets to characterizing their architectures and atmospheres in depth. In this work, ephemerides are updated for 22 Kepler planets and 4 Kepler planet candidates, constituting all Kepler planets and candidates with sufficient signal to noise in the TESS 2 min data set. A purely photometric method is utilized here to allow ephemeris updates for planets even when they do not posses significant radial velocity data. The obtained ephemerides are of very high precision and at least seven years ‘fresher’ than archival ephemerides. In particular, significantly reduced period uncertainties for Kepler-411d, Kepler-538b, and the candidates K00075.01/K00076.01 are reported. O–C diagrams were generated for all objects, with the most interesting ones discussed here. Updated TTV fits of five known multiplanet systems with significant TTVs were also attempted (Kepler-18, Kepler-25, Kepler-51, Kepler-89, and Kepler-396), however these suffered from the comparative scarcity and dimness of these systems in TESS. Despite these difficulties, TESS has once again shown itself to be an incredibly powerful follow-up instrument as well as a planet-finder in its own right. Extension of the methods used in this paper to the 30 min-cadence TESS data and TESS extended mission has the potential to yield updated ephemerides of hundreds more systems in the future.

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Pireaux, Sophie, E. Myles Standish, Elena V. Pitjeva, and Jean-Pierre Rozelot. "Solar quadrupole moment from planetary ephemerides: present state of the art." Proceedings of the International Astronomical Union 2, no. 14 (August 2006): 473. http://dx.doi.org/10.1017/s1743921307011489.

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29

Standish, E. M. "The Orientation of Future JPL Planetary Ephemerides." Highlights of Astronomy 10 (1995): 204. http://dx.doi.org/10.1017/s153929960001100x.

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AbstractIn the future, the ephemerides produced at JPL will be based upon the reference frame of the radio source catalogues. Recent planetary observations have been made directly with respect to the radio frame, and these observations have shown a satisfying degree of absolute accuracy and internal consistency; they provide an automatic frame-tie.

30

Fienga, A., C. Avdellidou, and J. Hanuš. "Asteroid masses obtained with INPOP planetary ephemerides." Monthly Notices of the Royal Astronomical Society 492, no. 1 (December 5, 2019): 589–602. http://dx.doi.org/10.1093/mnras/stz3407.

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ABSTRACT In this paper, we present masses of 103 asteroids deduced from their perturbations on the orbits of the inner planets, in particular Mars and the Earth. These determinations and the INPOP19a planetary ephemerides are improved by the recent Mars orbiter navigation data and the updated orbit of Jupiter based on the Juno mission data. More realistic mass estimates are computed by a new method based on random Monte Carlo sampling that uses up-to-date knowledge of asteroid bulk densities. We provide masses with uncertainties better than 33${{\ \rm per\ cent}}$ for 103 asteroids. Deduced bulk densities are consistent with those observed within the main spectroscopic complexes.

31

Walter, H. G. "Effects of precession uncertainties on planetary ephemerides." Symposium - International Astronomical Union 172 (1996): 475–76. http://dx.doi.org/10.1017/s0074180900127901.

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Several methods of data analysis applied recently to precise astrometric observations give evidence for a correction of the luni-solar precession (ψ) of the order of Δψ = −3 milliarcseconds per year (Williams et al., 1994). When studying the motion of bodies of the planetary system from photographic observations, an inertial stellar reference frame is required. Thus, any imperfection of the luni-solar precession would have repercussions on the determination of the orbit dynamics of the celestial body under investigation.

32

Seidelmann, P. K., E. J. Santoro, and K. F. Pulkkinen. "Systematic differences between planetary observations and ephemerides." Symposium - International Astronomical Union 114 (1986): 99–103. http://dx.doi.org/10.1017/s0074180900148041.

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33

Arlot, Jean-Eudes, Kaare Aksnes, Carlo Blanco, Nikolaj V. Emelianov, Robert A. Jacobson, George A. Krasinsky, Jay H. Lieske, et al. "DIVISION I-III / WORKING GROUP NATURAL PLANETARY SATELLITES." Proceedings of the International Astronomical Union 4, T27A (December 2008): 69–71. http://dx.doi.org/10.1017/s1743921308025337.

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The main goal of the Working Group was to gather astrometric observations made during the triennum as well as old observations not yet published in the data base. The WG encouraged the making of new observations. A Spring School was organized in China in order to teach the observational techniques of natural satellites to students and young astronomers. New theoretical models of the motion of the satellites and fit of the current models to new observations were used in order to make ephemerides of all the planetary satellites with tools useful for observations such as configurations. These ephemerides named MULTISAT are available at <www.imcce.fr/sat> or at <lnfm1.sai.msu.ru/neb/nss/nssephme.htm>.

34

Pitjeva, E. V. "EPM — High-Precision Planetary Ephemerides of IAA RAS for Scientific Research and Astronavigation on the Earth and in Space." Proceedings of the International Astronomical Union 10, H16 (August 2012): 221–22. http://dx.doi.org/10.1017/s174392131400550x.

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AbstractThe last version of the planet part of EPM's ephemerides of IAA RAS (EPM2011) is described briefly. At present EPM ephemerides are the basis for the Russian Astronomical and Nautical Astronomical Yearbooks and are used for scientific research.

35

Pitjeva, E. V. "EPM ephemerides and relativity." Proceedings of the International Astronomical Union 5, S261 (April 2009): 170–78. http://dx.doi.org/10.1017/s1743921309990342.

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AbstractIn the seventies of the last century the EPM ephemerides (Ephemerides of Planets and the Moon) of IAA RAS originated and have been developed since that time. These ephemerides are based upon relativistic equations of motion of celestial bodies and light rays and upon relativistic time scales. The updated model of EPM2008 includes the new values of planet masses and other constants, the improved dynamical model with adding Trans–Neptunian Objects and the expanded database (1913–2008). More than 260 parameters have been determined while improving the planetary part of EPM2008 to 550000 observations. EPM2008 have been oriented to ICRF by including into the total solution the VLBI data of spacecraft near the planets. The real uncertainty of EPM ephemerides has been checked by comparison with the JPL's DE ephemerides. Some estimates of the post–model parameters have been obtained: |1−β| < 0.0002, |1−γ| < 0.0002, /G = (−5.9±4.4) ⋅ 10−14 per year, the statistic zero corrections to the planet perihelion advances.

36

Robustelli, Umberto, and Giovanni Pugliano. "Galileo Single Point Positioning Assessment Including FOC Satellites in Eccentric Orbits." Remote Sensing 11, no. 13 (June 30, 2019): 1555. http://dx.doi.org/10.3390/rs11131555.

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On August 2016, the Milena (E14) and Doresa (E18) satellites started to broadcast ephemeris in navigation message for testing purposes. As the Galileo constellation is not yet complete. It is very important to have two more satellites available since the position accuracy increases as the number of visible satellites increases. In this article, we examine how the inclusion of the Milena (E14) and Doresa (E18) satellites impacts the position accuracy. The analysis was carried out on 20 days of 1-Hz observations collected by a receiver placed in YEL2IGS (International GNSS service) station. Two different scenarios are considered: the first excludes the measurements coming from the analyzed satellites, while the second one includes them. The analysis was conducted by using a suitable software tool developed in the MATLAB® environment able to compute satellites position from both the broadcast and precise ephemerides, to assess DOP (Dilution Of Precision) parameters and to compute single-point positioning for all Galileo frequencies. The analyses are conducted by using both broadcast and precise ephemeris. The inclusion of the two satellites improves the system availability, varying it from 94.1–97.94%, the DOP parameters, and the percentages of achieved positioning solutions by about 5% regardless of the frequency used. Nevertheless, in the positioning domain, when the broadcast ephemerides are used, the inclusion of the satellites worsens both the horizontal and vertical accuracy of the solution. The deterioration of the horizontal accuracy goes from 0.17 m with E5a frequency measurements to 0.74 m with E1 measurements. The reduction of vertical accuracy goes from 0.68 m for E5a to 1.2 m for E1 measurements. However, if precise ephemerides are used, both the horizontal and the vertical accuracy remain stable, actually for the E5b frequency, the DRMS (Distance Root Mean Squared) improves by almost 0.5 m. The results achieved show that the real drawback to overcome is related to the quality of broadcast ephemeris as, when precise ephemeris are used, the number of solutions achieved is increased by about 5% with an accuracy similar to that obtained when the satellites are excluded.

37

Fukushima, Toshio. "Time ephemeris and general relativistic scale factor." Proceedings of the International Astronomical Union 5, S261 (April 2009): 89–94. http://dx.doi.org/10.1017/s1743921309990202.

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AbstractTime ephemeris is the location-independent part of the transformation formula relating two time coordinates such as TCB and TCG (Fukushima 1995). It is computed from the corresponding (space) ephemerides providing the relative motion of two spatial coordinate origins such as the motion of geocenter relative to the solar system barycenter. The time ephemerides are inevitably needed in conducting precise four dimensional coordinate transformations among various spacetime coordinate systems such as the GCRS and BCRS (Soffelet al. 2003). Also, by means of the time average operation, they are used in determining the information on scale conversion between the pair of coordinate systems, especially the difference of the general relativistic scale factor from unity such asLC. In 1995, we presented the first numerically-integrated time ephemeris, TE245, from JPL's planetary ephemeris DE245 (Fukushima 1995). It gave an estimate ofLCas 1.4808268457(10) × 10−8, which was incorrect by around 2 × 10−16. This was caused by taking the wrong sign of the post-Newtonian contribution in the final summation. Four years later, we updated TE245 to TE405 associated with DE405 (Irwin and Fukushima 1999). This time the renewed vale ofLCis 1.48082686741(200) × 10−8Another four years later, by using a precise technique of time average, we improved the estimate of Newtonian part ofLCfor TE405 as 1.4808268559(6) × 10−8(Harada and Fukushima 2003). This leads to the value ofLCasLC= 1.48082686732(110) × 10−8. If we combine this with the constant defining the mean rate of TCG-TT,LG= 6.969290134 × 10−10(IAU 2001), we estimate the numerical value of another general relativistic scale factorLB= 1.55051976763(110) × 10−8, which has the meaning of the mean rate of TCB-TT. The main reasons of the uncertainties are the truncation effect in time average and the uncertainty of asteroids' perturbation. The former is a natural limitation caused by the finite length of numerical planetary ephemerides and the latter is due to the uncertainty of masses of some heavy asteroids. As a compact realization of the time ephemeris, we prepared HF2002, a Fortran routine to compute approximate harmonic series of TE405 with the RMS error of 0.446 ns for the period 1600 to 2200 (Harada and Fukushima 2003). It is included in the IERS Convention 2003 (McCarthy and Petit 2003) and available from the IERS web site;http://tai.bipm.org/iers/conv2003/conv2003_c10.html.

38

Chandler, J. F. "Pulsars and solar-system ephemerides." Symposium - International Astronomical Union 172 (1996): 105–12. http://dx.doi.org/10.1017/s0074180900127196.

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The analysis of pulsar time-of-arrival data is intimately bound up with planetary ephemerides. Highly accurate ephemerides are required for Earth and Moon and, to a lesser degree, for the other planets, in order to make full use of the timing data for millisecond-class pulsars. These data, in turn, present an opportunity for improving planetary ephemerides in a variety of ways. Fitting the Earth and Moon orbital parameters to the timing data is the obvious first step, though it is less valuable in the short term for many applications than using the current accumulation of spacecraft-tracking and lunar laser ranging data. By themselves, the pulsar timing data convey no information on the orientation of Earth's orbit, since each pulsar's position on the sky must be determined from those same data. However, independent pulsar position measurements by VLBI, in combination with the timing-derived positions, can serve to fix the orientation of Earth's orbit with respect to the radio reference frame and thereby link the planetary and radio frames. In the long run, the acquisition of timing data over increasing time spans and with improving precision should prove to be an important factor in determining the shape, as well as the orientation, of Earth's orbit. In addition, pulsar timing over a sufficiently long span can directly measure a planet mass through the reaction of the rest of the solar system. The effect must be observed for a major fraction of the orbital period of the planet in question so that the signature can be separated from that of the ordinary spin-down of each pulsar. Finally, pulsar timing can be used to probe gravitational physics, a field with far-reaching consequences and a basic part of the framework for constructing the ephemerides.

39

Abalakin, Victor K. "Ephemerides and Celestial Mechanics." Highlights of Astronomy 7 (1986): 65–68. http://dx.doi.org/10.1017/s1539299600006195.

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When solving some abstract problems in mechanics related to the dynamics of bodies and systems, the notion of an inertial frame of reference is introduced in an apparently clear and natural way by simply drawing its coordinate axes and then paying no further attention to the system of reference which is then taken for granted. If we turn, however, towards investigations of the real stellar and planetary world, or as Sir James Jeans put it, “… to the Universe around us,” we immediately face the question of how to practically construct a useful and obvious model of the inertial frame of reference sufficiently close to reality.

40

Desmars, J., J. E. Arlot, and A. Vienne. "Influence of the astrometric accuracy of observation on the extrapolated ephemerides of natural satellites." Proceedings of the International Astronomical Union 3, S248 (October 2007): 96–97. http://dx.doi.org/10.1017/s174392130801870x.

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AbstractThe accuracy of planetary satellites ephemerides is determined not only by the accuracy of dynamical model (internal accuracy) but also by the accuracy of the observations (external accuracy) used to fit the initial parameters of a model. This external accuracy extrapolated in the future is unknown most of the time and tends to degrade the global accuracy of ephemerides. Even if we can estimate the quality of the ephemerides by comparison with observations, we do not know how to determinate the evolution of the accuracy outside the period of observations. We will present a statistical method, resampling of observations, which allows a better estimation of the extrapolated accuracy in the future.

41

Emelyanov, Nikolay. "Precision of the ephemerides of outer planetary satellites." Planetary and Space Science 58, no. 3 (February 2010): 411–20. http://dx.doi.org/10.1016/j.pss.2009.11.003.

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42

Standish, E. Myles. "On the Reference Frame of the Planetary Ephemerides." Symposium - International Astronomical Union 109 (1986): 677–83. http://dx.doi.org/10.1017/s0074180900077184.

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The planetary and lunar ephemerides have their own inherent reference frame which is one of the key frames to be considered in the unification of the many present day frames, both celestial and terrestrial. The use of this frame requires an understanding of its own accuracies, both internal (i.e., relative) and external(e.g., w.r.t. the FK4 system or w.r.t. the dynamical equinox). Such accuracies are discussed in this paper. Also noted are the expected improvements in the future which will be obtained from newer data types.

43

Choliy, V. Ya. "On the precision estimation of fundamental planetary ephemerides." Kinematics and Physics of Celestial Bodies 30, no. 6 (November 2014): 304–7. http://dx.doi.org/10.3103/s0884591314060038.

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44

Pitjeva, E. V., and N. P. Pitjev. "Development of planetary ephemerides EPM and their applications." Celestial Mechanics and Dynamical Astronomy 119, no. 3-4 (August 2014): 237–56. http://dx.doi.org/10.1007/s10569-014-9569-0.

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45

Standish, E. M. "Early Observations and Modern Ephemerides." Highlights of Astronomy 12 (2002): 326–29. http://dx.doi.org/10.1017/s1539299600013666.

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AbstractThere is a great variety of planetary and lunar observations recorded throughout history. Even today, some of these are useful for the improvement of ephemerides, though one must use a lot of judgment and caution - for surprising reasons. Five different sets of observations are presented, each with a story and a lesson: Galileo’s observations of Neptune, Lalande’s observations of Neptune, Williams’ measurements of the 1780 solar eclipse, Robertson’s 1811 transit timings, and solar eclipses in general.

46

Arlot, J. E., A. Bec-Borsenberger, and G. Dourneau. "Observations of the Planetary Satellites Europa and Titan by Hipparcos." International Astronomical Union Colloquium 127 (1991): 206–9. http://dx.doi.org/10.1017/s0252921100063776.

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AbstractObservations of the satellites Europa and Titan will be obtained from the European Astrometric Satellite HIPPARCOS. These observations will be used to obtain “observed” positions of the planets Jupiter and Saturn; these positions have the advantages, first to be given in the reference frame defined by the Hipparcos system, and second, the accuracy on these positions is better than the accuracy of the ground-based observations of these planets. To obtain the positions of the planets from those of their satellites, we have to take the calculated positions of these satellites by means of their ephemerides. The accuracy of the computed positions of Europa and Titan relatively to their primary is of the order of 0ʺ.l, better than the one of the direct observation of Jupiter and Saturn. An efficient comparison of the different ephemerides of these planets will be possible that way.

47

Hilton, James L., Charles Acton, Jean-Eudes Arlot, Steven A. Bell, Nicole Capitaine, Agnès Fienga, William M. Folkner, et al. "Appendix: Final Update of the IAU Division A Commission 4 Working Group on Standardizing Access to Ephemerides and File Format Specification." Proceedings of the International Astronomical Union 11, T29A (August 2015): 22–23. http://dx.doi.org/10.1017/s1743921316000600.

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AbstractThe IAU Commission 4 Working Group on Standardizing Access to Ephemerides recommends the use of the Spacecraft and Planet Kernel (SPK) format to provide a uniform format for the position ephemerides of planets and other natural solar system bodies, and the use of the Planetary Constants Kernel (PCK) for the orientation of these bodies. These formats are used by the SPICE system, developed by the Navigation and Ancillary Information Facility of NASA's Jet Propulsion Laboratory. The working group's final report is currently undergoing final preparations for publication. A long version of this report will be available at the IAU Commission 4: Ephemerides (or its successor) web site. This long version will contain a full description of that portion of the SPK and PCK formats required to duplicate these file types for this application.

48

Folkner, W. M., and J. S. Border. "Linking the planetary ephemeris to the International Celestial Reference Frame." Proceedings of the International Astronomical Union 10, H16 (August 2012): 219–20. http://dx.doi.org/10.1017/s1743921314005493.

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AbstractThe largest uncertainty in the ephemerides for the inner planets is in the orientation of the dynamical system to the celestial reference frame. A program of VLBI measurements of spacecraft in orbit about Venus and Mars has been performed to reduce the orientation uncertainty to 0.2 milliarcseconds.

49

Standish, E. M. "Comments on Recommendation III of the IAU Working Group on Reference Systems." Highlights of Astronomy 9 (1992): 151–53. http://dx.doi.org/10.1017/s153929960000887x.

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IAU Recommendations should 1) help to avoid confusion and 2) help to enhance scientific capability. Recommendation III does neither. It would create confusion while doing nothing to improve scientific results.If Recommendation III is ever implemented, the result will be sheer chaos. This recommendation proposes that the rate of the basic ephemeris time scale be changed – by an amount of nearly one-half second per year. This implies that all existing planetary, lunar, satellite, spacecraft, asteroid and comet ephemerides would be referenced to an obsolete time scale; all existing sets of orbital elements would need a modification; that epoch J2000 (JED 2451545.0) would differ from the presently defined one by nearly 15 seconds.

50

Fukushima, T. "Determination of LC and LB." Highlights of Astronomy 10 (1995): 205. http://dx.doi.org/10.1017/s1539299600011011.

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The location-independent part of TCB-TCG, the difference between the two new time scales adopted by the IAU (1992), was integrated numerically for three JPL planetary/lunar ephemerides; DE102, DE200, and DE245. The differences among these three integrations were mostly explained by the difference in the adopted constants of the ephemerides. It was shown that the post-Newtonian correction and the perturbation by asteroids are negligible except for the mean rate, LC. The comparison of these numerical integrations with the analytical formulas of Hirayama et al. (1987) and Fairhead and Bretagnon (1990) as well as their extended versions lead to the best estimate of LC asCombining this with the recent value of the geoid potential in Bursa et al. (1992), we estimated the value of LB, the scale difference between TCB and TT, asTable I summarizes these conclusions. These estimates of LC and LB are more reliable than the former values we gave (Fukushima et al. 1986). The new estimate of LB will be useful in converting the numerical values of some precisely determined astronomical constants such as AU measured in meter from those in TDB to those in TCB. Also the numerically integrated TCB-TCG, which are to be called Time Ephemeris, will be useful when converting between TCB and TDB, i.e. the time scales themselves. The full paper will be appeared in A & A with the title of Time Ephemeris.

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