Context. There is a need in some research facilities for deriving ephemerides, controlling observations, verifying various models of motion, and calculating the coordinates in space of natural planetary satellites. Aims. The goal of our work is to elaborate the ephemerides of all natural satellites based upon all observations available to date and readily accessible for any user via the Internet. Methods. For all outer planetary satellites, original numerical models of motion are used that are based on all published observations. For other satellites, the theoretical models of the motion are taken from publications that are as recent as possible. Complete collection of the theories and models of motion is realized as a software for the ephemerides of natural satellites available on the web pages of the so-called server MULTI-SAT. Results. A new facility for producing ephemerides of all natural satellites of planets (except the Moon) has been created at IMCCE and SAI. Special features of the ephemerides are realized, such as predicting the phenomena and providing configurations useful for the observers. The server MULTI-SAT is accessible through the Internet. The URL addresses are http://www.imcce.fr/sat (English and French versions at IMCCE) and http://www.sai.msu.ru/neb/nss/index.htm (English, French, and Russian versions at SAI). This paper includes a complete review of the most precise theories of motion of all natural satellites that we used and an analysis of the precision of the proposed ephemerides.

Context. Any study of the dynamics of the Natural Planetary satellites needs to gather as many astrometric observations as possible of those that have been observed for centuries. This kind of work is partially made by each astronomer starting this kind of study but has never been done for all the satellite systems. Aims. The goal of our work is to build a database of all the available astrometric observations, together with all the information needed for efficient use of these data, and to avoid astronomers interested in the dynamics of Planetary satellites have to redo this data search. Methods. To do this we had to find and carefully read all the publications including observational data, international journals, or internal reports to be able to add the observations in the database knowing the reference frame used by the observer, the corrections and reduction made, and the time scale needed to link all the data. We also had to contact observatories and observers to be sure to have the raw data available. We gathered the bibliographic references related to the observations put in the database. Results. A new database containing about 90 percent of all the observations useful for studying the dynamics of the satellites is now available for the interested community of astronomers. NSDB is accessible on the Internet: http://www.imcce.fr/nsdc (IMCCE) and http://lnfm1.sai.msu.ru/neb/nss/nssnsdcme.htm (trilingual version of SAI).

Context. In 2009, the Sun and the Earth passed through the equatorial plane of Jupiter and therefore the orbital planes of its main satellites. It was the equinox on Jupiter. This occurrence made mutual occultations and eclipses between the satellites possible. Experience has shown that the observations of such events provide accurate astrometric data able to bring new information on the dynamics of the Galilean satellites. Observations are made under the form of photometric measurements, but need to be made through the organization of a worldwide observation campaign maximizing the number and the quality of the data obtained. Aims. This work focuses on processing the complete database of photometric observations of the mutual occultations and eclipses of the Galilean satellites of Jupiter made during the international campaign in 2009. The final goal is to derive new accurate astrometric data. Methods. We used an accurate photometric model of mutual events adequate with the accuracy of the observation. Our original method was applied to derive astrometric data from photometric observations of mutual occultations and eclipses of the Galilean satellites of Jupiter. Results. We processed the 457 lightcurves obtained during the international campaign of photometric observations of the Galilean satellites of Jupiter in 2009. Compared with the theory, for successful observations, the r.m.s. of O-C residuals are equal to 45.8 mas and 81.1 mas in right ascension and declination, respectively; the mean O-C residuals are equal to -2 mas and -9 mas in right ascension and declination, respectively, for mutual occultations; and -6 mas and +1 mas in right ascension and declination, respectively, for mutual eclipses.

Ephemerides of natural satellites are needed to carry out space missions to planets and to study the dynamics of Solar system bodies. Continuous observations of planetary satellites allow new, more accurate ephemerides to be derived. In this paper a new model of the motion of the Neptunian satellite Nereid is developed. The model is based on all published (736) and unpublished (140) ground‐based observations and 72 observations made by the Voyager spacecraft in 1989. The root‐mean‐square (rms) deviations of the observed satellite coordinates from their theoretical values are equal to 0.30 and 0.32 arcsec in right ascension and declination, respectively. The main contributors to these deviations are early ground‐based observations of Nereid. Estimations of the precision of the ephemeris of Nereid made by our original method show that the errors of the ephemeris do not exceed 0.03 arcsec (1σ) up to 2020. Comparing our ephemeris of Nereid with the Jet Propulsion Laboratory (JPL) results, the discrepancies do not exceed 0.04 arcsec in right ascension and declination over the 1980–2011 time period. A new ephemeris of Nereid is proposed via the MULTI‐SAT ephemeris facility.

Abstract. In 1998 and 1999, we started observations of the 9th satellite of Saturn. We made 163 observations using the 120 cmtelescope of Observatoire de Haute-Provence, France. We used the USNO A2 catalogue 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 with the most recent theories was made.