Report on Satellites for the period July 2002- June 2005(J.E. Arlot)


1) Activities of the Working Group on Natural Planetary Satellites (J.E. Arlot, chairman)

The activities of the working group on Natural planetary satellites were
mainly dedicated to the maintenance of the data base of astrometric
observations of the natural planetary satellites:

- mutual events of the galilean satellites: most of the events observed during 
the past campaigns are available; the lightcurves are available for 1985, 1991 and 1997

- astrometric observations: most of the observations made in the countries
of the former soviet union before 1990 are now available and old data are under scanning to
be added to the data base which has been presented by Emelianov and Arlot at the
American Astronomical Society, DPS meeting #37, #47.06.

- bibliographic data: all the astrometric data are documented
through the data base of the papers where they were published. Theoretical papers 
are also included in the database.

An effort has been made to use the best dynamical theories to build
ephemerides for use by the observers of the natural planetary satellites.

The site of the working group is available at the address:
http://www.imcce.fr/iauwg
The data base is available at the address:
http://www.imcce.fr/nsdc


2) Astrometric observations performed during the triennum 2002-2005

Numerous discoveries were made thanks to large telescopes
exploring the sky where new faint satellites may be found. The
known satellites were observed either from ground-based
telescopes, or from space in order to maintain the quality
of the dynamical models of their motions. 

a) Discovery of new satellites

Many new outer satellites of the giant planets were discovered during
the past triennum such as S/2001 U 3 (Marsden et al., 2003), S/2001 U 2 
and S/2002 N 4 (Holman et al. 2003), S/2001 U 1 (Holman et al. 2002),
S/2002 J 1 (Sheppard et al. 2002), S/2003 J 22 (Sheppard et al. 2004),
S/2003 J 19 and S/2003 J 20 (Gladman et al. 2003), S/2003 J 8 (Sheppard
et al. 2003), S/2003 U 3 (Sheppard et al. 2003), S/2003 U 1 and S/2003 U 2
(Showalter et al. 2003), S/2005 S 1 (Porco, 2005. Other new satellites 
of Saturn were announced by Sheppard et al. (2005) and by Jewitt et al.
(2005).
A Survey for Outer Satellites of Mars and determination of the Limits to 
Completeness was made by Sheppard et al. in AJ, 128, 2542 (2005). 


b) Observations of known satellites

Mutual events and phenomena of the galilean satellites observed in 1997 and 
2003 were published by Dourneau et al. in A&A 437, 711 (Bordeaux Observatory, 
France), by Pauwels et al. in A&A 437, 705 (Uccle-Bruxelles Observatory, Belgium),
by Loader in New-Zealand (2004) and by Vienne et al. at Lille Observatory, 
France (2003).

U.S. Naval Observatory (USA):
Using Hubble Space Telescope Astrometric Observations, Pascu et al. made Orbital 
Mean Motion Corrections for the Inner Satellites of Neptune in AJ 127, 2988.
Upgrades to the Flagstaff Astrometric Scanning Transit Telescope were made
by Stone et al. in AJ 126, 2060.

China:
Astrometry is under development in China as shown by Jin Weng-Jing et al.(2004) and 
1997-2000 CCD astrometric observations of Saturn's satellites and comparison 
with theories have been published by Qiao et al. in A&A 422, 377 (2004)

Institut de mecanique celeste (Paris, France):
CCD observations of Phoebe have been published by Fienga et al. in A&A 391, 767 (2002).

Ukraine:
Astrometric CCD observations of the inner Jovian satellites in 1999-2000
were published by Kulyk et al. in A&A 383, 724 (2002)

Minor Planet Center, Cambridge (USA):
The Minor Planet Center has concerned itself with
announcing new discoveries of planetary satellites (in collaboration with
CBAT, which is responsible for assigning designations to new discoveries),
determining preliminary orbits, publishing follow-up astrometry and updating
orbits as necessary and disseminating observational and orbital information
via the MPECs and Minor Planet Circulars. 

Rio de Janeiro Observatory, CNPq, (Brazil):
Many sets of observations were published: CCD astrometric observations of 
Amalthea and Thebe by Veiga and Vieira Martins in A&A 437, 1147 (2005); 
CCD astrometric observations of Saturnian satellites by Veiga et al. in
A&A 400, 1095 (2003); Positions of Uranus and Its Main Satellites by
Veiga et al. in AJ, 125, 2714; Systematic astrometric observations of Proteus
by Vieira Martins et al. in A&A 425 1107 (2004)

JPL, Pasadena (USA):
A paper on Groundbased Radar Investigations of Asteroids and Planetary 
Satellites was published by Ostro in AJ 123, 1776.

Observations from Space:
Solar eclipses of Phobos and Deimos were observed from the surface of Mars 
and published by Bell et al. in Nature 436, 55 (2005). A paper on the possible
observation of the Natural Satellites of Solar System Bodies with Gaia was
published by Tanga and Mignard in the Proceedings of the Gaia Symposium 
"The Three-Dimensional Universe with Gaia" (ESA SP-576). 
Jovian satellite positions from Hubble Space Telescope images were published
by Mallama et al. in Icarus 167,320.


3) Processing of observations

The processing and re-processing of existing observations allowed to
get new data very useful for dynamical purpose.

U.S. Naval Observatory, Washington D.C. (USA):
From scanning of the large USNO photographic plates archive new observations were
deduced from unmeasured plates by Pascu et al. (2005).

Institut de mecanique celeste (Paris, France) and IIA, Bangalore (India):
Observation and reduction of mutual events in the solar system were published by
Noyelles et al. in the Proceedings of IAU Colloquium #196, held 7-11 June, 2004 in 
Preston, U.K. and Astrometry from CCD photometry of mutual events of Jovian 
satellites from VBO during 1997 were published by Vasundhara in A&A 389,325 (2002).
Astrometry from mutual events of Jovian satellites in 1997 were published by 
Vasundhara et al. in A&A 410, 337 (2003).
 
China:
Image-processing techniques in precisely measuring positions of Jupiter and its 
Galilean satellites were published by Peng et al. in A&A 401, 773 (2003) and 
New confirmation of image-processing techniques for astrometry of Saturn and 
its satellites by Peng in MNRAS, 359, 1597. 


4) Ephemerides

Ephemerides of the natural planetary satellites are available
through Internet on the JPL site, the IMCCE and SAI sites and,
for the outer satellites of the giant planets, on the MPC site.

Sternberg Astronomical Institute SAI (Moscow, Russia):
Ephemerides of the outer Jovian satellites were published by Emelyanov in
A&A 435, 1173. 

Minor Planet Center, Cambridge (USA):
Ephemerides of the outer satellites of the giant planets are continuously
produced at the MPC and provided through Internet.

Institut de mecanique celeste IMCCE (Paris, France):
The mutual events of the Galilean Satellites of Jupiter for 2002-2003 
were calculated  by Arlot (2002) and are available through Internet together
with an interactive software allowing the calculation of the local
observational conditions. The mutual events including Amalthea were
also published by Vachier et al. in A&A 394, L19 (2002)
Concerning the Galilean satellites, ephemerides were published thanks to
a brand new theory by Lainey et al. in A&A 427, 371 (2004).

IMCCE (Paris, France) and SAI (Moscow, Russia):
Ephemerides of all the natural planetary satellites are available through
Internet on the web server of IMCCE and SAI.


5) Theoretical works 

Theoretical works were of two kinds: either developments allowing to make
ephemerides or analysis of the evolution of the dynamics of some
satellite system.

Theoretical works were continued on the motion of the satellites systems
and we will note the following works: Saturn's moon Phoebe as a captured body 
from the outer Solar was published by Johnson and Lunine in Nature 435, 69 
(2005). Cuk and Gladman published a paper on the Constraints on the Orbital 
Evolution of Triton in the Astrophysical Journal, Volume 626, p. L113.
Numerical Simulations of the Orbits of the Galilean Satellites were performed by
Musotto et al. published in Icarus 159, 500. A Collisional Origin of Families 
of Irregular Satellites was studied by Nesvorný et al. and published in
AJ 127, 1768. Nesvorný et al. also published a paper on Orbital and Collisional 
Evolution of the Irregular Satellites in AJ 126, 398. The Orbital Evolution of 
the Distant Satellites of the Giant Planets was studied by Vashkov'yak and Teslenko
in Astronomy Letters 31, 140 (2005).

JPL, Pasadena, USA:
A paper on the Orbits of the Major Saturnian Satellites and the Gravity Field of 
Saturn from Spacecraft and Earth-based Observations was published by Jacobson
in AJ 128, 492. The Origin of chaos in the Prometheus-Pandora system was studied by
Goldreich and Rappaport in Icarus 166, 320. Jacobson and Owen published a paper on
The Orbits of the Inner Neptunian Satellites from Voyager, Earth-based, and Hubble 
Space Telescope Observations in AJ 128, 1412.

Cornell University, USA:
Chaos and the Effects of Planetary Migration on the Orbit of S/2000 S5 Kiviuq 
was studied by Carruba et al. in AJ 128, 1899 and a paper on the Inclination 
Distribution of the Jovian Irregular Satellites was published by Carruba
et al. in Icarus 158, 434.

Queen Mary, University of London, UK:
The Dynamical Influences on the Orbits of Prometheus and Pandora were studied by
Cooper and Murray in AJ 127, 1204.

Torun Centre for Astronomy, N. Copernicus University, Poland:
An Analytical theory of the motion of Phobos and A comparison with numerical 
integration were studied in A&A 416, 1187 (2004).

Goddard NASA Center, USA:
Free and forced obliquities of the Galilean satellites of Jupiter were studied
by Bills in Icarus 175, 233.

Sternberg Astronomical Institute (Moscow, Russia):
The mass of Himalia from the perturbations on other satellites was determined
by Emelyanov in A&A 438, L33 and the Dynamics of Planetary Satellites in the 
Solar system were studied by Ural'skaya in Solar System Research 37, 337 (2003).

Institut de mecanique celeste (Paris, France):
A brand new theory of the motion of the Galilean satellites of Jupiter 
was made thanks to frequency analysis by Lainey et al. and published
in A&A 420, 1171 (2004) and and will be applied to make new 
ephemerides after fit to the available observations (Lainey and Vienne 2001,
in Colloq. CELMECIII, Rome,Italy). 
The masses and orbital positions of Prometheus and Pandora during the Cassini 
tour were published by Renner et al. in Icarus 174, 230.

University N-D de la Paix, Namur, Belgium:
The Rotation of Europa was studied by Henrard and published in Celestial 
Mechanics and Dynamical Astronomy, Volume 91, p. 131, using a semi-analytical 
theory of the rotation of Europa the Galilean satellite of Jupiter. The theory 
is semi-analytical in the sense that it is based on a synthetic theory of the 
orbit of Europa developed by Lainey. The theory is developed in the framework 
of Hamiltonian mechanics, using Andoyer variables and assumes that Europa is a 
rigid body. This theory is a first step toward the modelization of 
a non rigid Europa covered by an ocean.

Universidade Estadual Paulista, Brazil:
A study on the dynamics of some resonances of Phobos in the future was
published by Yokoyama et al. in A&A 429, 731 (2005). Yokoyama et al.
published also a study fn the orbits of the outer satellites of Jupiter 
in A&A 401, 763 (2003).
 
China:
A Re-determination of Phoebe's orbit was made by Shen et al. and published
in A&A 437, 1109 (2005).


6) Satellites of asteroids

Very few astrometric positions are available for the fit of a dynamical model
for any discovered satellite of asteroid and an effort is to be made to
gather these data for dynamical purpose. Publications are, most of time, made
in order to present discoveries.

A probable detection of a moon of asteroid 98 Ianthe and a moon of asteroid 
1024 Hale was published by Venable in Occultation Newsletter, (IOTA) Vol. 11, 
p. 5 and 8 (2004). A paper by Ryan et al. is entitled 3782 Celle: Discovery 
of a binary system within the Vesta family of asteroids and was published in
Planetary and Space Science, Volume 52, p. 1093. IAU Circ. 8232, 2 (2003)
announced the discovery of S/2003 (22899) 1 by Merline et al. and IAU Circ., 
7980, 2 (2002), also by Merline et al. announced the discovery of S/2002 (121) 1.


7) Rings

Most of the publications concerning the rings are dedicated to planetology
and few deal with the dynamics of the particles of the rings.

Local N-Body Simulations for the Rotation Rates of Particles in Planetary Rings
were published by Ohtsuki and Toyama in AJ 130, 1302. Three-dimensional Dynamics 
of Narrow Planetary Rings were published by Chiang and Culter in the Astrophysical
Journal, Volume 599, p. 675. A paper On the stability of Saturn's rings to gravity 
disturbances was published by Griv et al. in A&A 400, 375 (2003).