The Miriade project aims to provide a VO-compliant suite of services to compute positional and physical ephemerides of known solar system bodies, offering:

• ephemerides of planets, natural satellites, asteroids and comets for any location on Earth, as well as various location in space (HST, SPITZER, Gaia, etc.)
• radial velocity map, and in a near future albedo and thermal maps
• original features for the modelling of the physical aspect of asteroids, taking into account their spin and shape models made available from light-curve inversion techniques [15] and/or high resolution imaging from optical telescopes and radar observations
• different visualizations and data-format outputs for uploading and directly usable in any application. For instance, a FITS file showing the size, orientation brightness distribution, etc. of a given target at any epoch
• possibility to be used for further convolution with an instrument PSF or a transfer function
• computation of rise, set and transit of the major solar system bodies (Sun, Moon and planets)
• computation of visibility of Sso to prepare observing nights

The Miriade Web service provides the following methods (HTTP+XML+SOAP+WSDL):

ephemcc - position ephemeris

This method allows to compute the ephemerides of position of the known solar system bodies

ephemph - physical ephemeris

This method allows to compute the apparent aspect of some known solar system bodies

rts - rise, set and transit

This method allows to compute the rise, set and transit of the Sun, the Moon and the planets

vision - visibility service for observing nights

This method allows to compute the visibility of Sso to prepare their observations

And administrative methods:

Miriade availability

This method provides the availability of the Miriade web-service. Check now!

The Miriade service is an XML Web service that lives on the Web. You can access the published methods to compute the Sso ephemerides by making so called SOAP requests, or by using VO applications such as Aladin [16] (screenshot), Topcat, ... The underlying technology (XML+SOAP+WSDL) being inherently interoperable, you can use them and implement them regardless of what your favourite platform and operating system are. For that, you can freely download toolkits (client or plugin) to help you to make the integration of the Miriade service seamless with your code.

The easiest way to compute ephemerides with Miriade is to use the Miriade's query form or to use a non-interactive network downloader (e.g. curl, wget) to send HTTP requests and to receive the ephemerides "on your desktop".

Ephemerides of solar system objects (SSO) are highly needed in many applications of planetary science research. They are useful to the astronomer to prepare his observations proposal and to analyze observational data, for accurate modelling of space-probe orbits to simulate their fly-by and their encounter with planetary systems, for predicting instruments performances of moving and extended objects, etc.

Since more than 2 centuries, the Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), an institute of the CNRS / Observatoire de Paris (France), studies dynamics and physics of solar system bodies, and conceives planetary theories (VSOP [2,4], INPOP [14]). This research work has led IMCCE to be a major actor of ephemerides computation of planets, natural satellites, asteroids, comets, meteoroids and meteor streams.

Since the 1990's, IMCCE has started to design and develop various services of computation of positional and physical ephemeris of SSO. Since the 2000's, the advent of the Virtual Observatory offered a new vision of the delivery of services to astronomers with the arrival of the concept of interoperability. Prior the VO, numerous services was existing but they required to manage by hand the inter-connexion between resources and applications. Nowadays, the VO framework allows applications and data to be easily interoperable such that astronomers have access on top of their desktop to many applications that enable them to explore and bookmark resources from around the world, to query databases, to plot and manipulate tables, and to realize complex calculations. This is in this framework that IMCCE started to put at the disposal of astronomers a suite of tools dedicated to solar system objects.

The planetary ephemerides provided by Miriade are based on the use of the calculation algorithms of the solar system bodies' ephemerides described by Kaplan et al. (1989) [1]. The geometry is Euclidean and movements are newtonniens and take into account the post-newtonian approximation. The masses of planets are those of UAI 1976 and IERS 1992 according to the choice of planetary theory (UAI 1976 for VSOP82 [2], DE200 [3] and VSOP87 [4]; IERS 1992 for DE40x [5] except for Saturn and Uranus masses which are specific to DE40x). The references systems are the FK5 (for VSOP82, DE200 and VSOP87) and the ICRF (for DE40x). The astronomical constants are those of UAI 1976, UAI 1982 and IERS 1992 systems according to case.

The osculatory elements of asteroids come from the ASTORB database of the Lowell observatory [17]. The osculatory elements of comets come from the IMCCE's Cometary Notes [18].

The physical properties of the solar system bodies come from various published works. The spin elements of the planets and satellites come from the reports of the IAU Working Group on Cartographic Coordinates and Rotational Elements [21].

A detailed description of the solar system bodies's ephemerides calculations are available in the Introduction aux éphémérides astronomiques [10], or in brief in Definitions relatives aux éphémérides de position des corps célestes (in french) [11], and Définitions relatives aux éphémérides pour l'observation physique des corps du système solaire (in french) [19], and in the bibliographic references listed below.

The thermal flux of asteroids is computed according to the Near-Earth Asteroid Thermal Model (NEATM) [20] implemented by the Lagrange laboratory (Observatoire de la Côte d'Azur) and IMCCE.

The Miriade service has been designed and developed by the IMCCE (Observatoire de Paris / CNRS) in the framework of the IMCCE Virtual Observatory project (2004-2012). It is supported by the VO-Paris Data Centre, the french VO, and the EuroPlaNet project. The Miriade service is hosted by IMCCE, and is accessible through HTTP query methods and XML+SOAP+WSDL Web service.

The asteroid database used by Miriade is updated once a week (monday early morning) to include lately discovered bodies, and to be synchronized with the ASTORB database hosted by CDS. The comet database is updated three times per week with the lately discovered objects published by the Minor Planet Center. For planets and natural satellites, the update occurs when new orbital solutions are published in peer-review papers. The hardware infrastructure of Miriade allows the service to be available all the time, even when the update process runs.

Each response sent back by the Miriade service contains a ticket number. This 12 digits number (e.g. 123003240449) identifies each request and may be used to retrieve information on its processing. If you face with errors by using the Miriade service (it could occur that no relevant error message is returned), please report us the ticket number corresponding to the problem. It will help you to anderstand and solve it, and you will help us to improve the service.

The information regarding requests sent to Miriade is stored in a dedicated database. No personal information is stored, except the IP address provided by the client, which is employed to make statistics on the geographical localization of the Miriade users. The Miriade logs are never disseminated nor sent on request. You can access to the public logs by using the following URL:

http://vo.imcce.fr/webservices/miriade/showLog.php?ticket=[#ticket]&method=[method]

where:

#ticket

Ticket number of the request

method

Keyword defining the service: Miriade(ephemcc), Miriade(ephemph), Miriade(rts), Miriade(vision), Miriade(getAvailability)

If you are confronted with a bug, or if you would like to request improvements or special needs, please use the IMCCE Mantis Bug Tracker (quick access: use the Report issue menu in the portal menubar).

The numerical precision of the Miriade ephemerides differ from one target to another, mainly depending on the accuracy of the orbital elements. As a consequence, you should not consider the accuracy of the computed positions as the number of digit which is provided. It is only a numerical accuracy that is given to avoid truncation error.

In any case, the IMCCE cannot be held for person in charge for a misuse or interpretation of the Miriade service and the data that are provided.

If Miriade was helpful for your research work, the following acknowledgment would be appreciated: "This research has made use of IMCCE's Miriade VO tool"

1. G.H. Kaplan, J.A. Hughes, P.K. Seidelmann, C.A. Smith. Mean and apparent place computations in the new IAU system. III. Apparent, topocentric, and astrometric places of planets and stars. Astronomical Journal, 97(4), 1989
2. P. Bretagnon. Theory for the motion of all the planets - The VSOP82 solution, Astron. & Astrophys., 114, 1982
3. E.M. Standish. The observational basis for JPL's DE200, the planetary ephemerides of the Astronomical Almanac, Astron. & Astrophys., 233, 1990
4. P. Bretagnon, G. Francou. Planetary theories in rectangular and spherical variables. VSOP87 solutions, Astron. & Astrophys., 202, 1988
5. E.M. Standish, X.X. Newhall, J.G. Williams, W.F. Folkner. JPL planetary and lunar ephemerides, DE403/LE403, JPL IOM, 314, 1995
6. V. Lainey, V. Dehant, M. Patzold First numerical ephemerides of the Martian moons, Astron. & Astrophys., 465, 2007
7. V. Lainey, J.E. Arlot, A. Vienne New accurate ephemerides for the Galilean satellites of Jupiter. II. Fitting the observations Astron. & Astrophys., 427, 2004
8. A. Vienne, L. Duriez. TASS 1.6: Ephemerides of the major Saturnian satellites, Astron. & Astrophys., 297, 1995
9. J. Laskar. GUST86 - An analytical ephemeris of the Uranian satellites, Astron. & Astrophys., 188, 1987
10. Introduction aux éphémérides astronomiques, supplément explicatif à la Connaissance des temps, Bureau des longitudes (Les Editions de Physique), 1997 (more info)
11. J. Berthier, Définitions relatives aux éphémérides de position des corps célestes, Note scientifique et technique du Bureau des longitudes, S060, Bureau des longitudes, 1998 (download)
12. H. Yan, A new expression for astronomical refraction. Astron., Journal, 112(3), 1996
13. M. Chapront-Touzé J. Chapront, The lunar ephemeris ELP 2000, Astron. & Astrophys., 124, 1983
14. A. Fienga, H. Manche, J. Laskar, M. Gastineau, INPOP06: a new numerical planetary ephemeris, Astron. & Astrophys., 477, 2008
15. J. Durech, M. Kaasalainen, A. Marciniak, W. H. Allen, R. Behrend, C. Bembrick, T. Bennett, L. Bernasconi, J. Berthier, G. Bolt, and 32 coauthors, Physical models of ten asteroids from an observers' collaboration network, Astron. & Astrophys., 465, 2007 (more info)
16. F. Bonnarel, P. Fernique, O. Bienaymé, D. Egret, F. Genova, M. Louys, F. Ochsenbein, M. Wenger, J. G. Bartlett, The ALADIN interactive sky atlas. A reference tool for identification of astronomical sources, Astron. & Astrophys. Supplement, 143, 2000 (more info)
17. T. Bowell, Asteroid Orbital Elements Database, Lowell Observatory, 2009 (more info)
18. P. Rocher, Notes cométaires, IMCCE, 2009 (more info)
19. J. Berthier, Définitions relatives aux éphémérides pour l'observation physique des corps du système solaire, Note scientifique et technique du Bureau des longitudes, S061, Bureau des longitudes, 1998 (download)
20. A. W. Harris, A Thermal Model for Near-Earth Asteroids, Icarus, vol. 131; issue 2, 1998 (link)
21. B. A. Archinal, M. F. A'Hearn, E. Bowell, et al., Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2009, Celestial Mechanics and Dynamical Astronomy, 109, 101, 2011 (link)