Français
Understanding > Astronomical calculations
Phenomena of the Galilean satellites of Jupiter - GUIDE
The four Galilean satellites of Jupiter, whose orbits are coplanar in the equatorial plane of the planet, show phenomena involving the planet Jupiter. During their revolutions around Jupiter, the satellites enter regularly into its shadow cone and we observe from Earth either an eclipse (E.C. or EC.D at the entrance and E.F. or EC.F at the exit from the shadow). They are also hidden regularly by the planet and we observe from Earth an occultation (IM. or OC.D as immersion at the beginning and EM. or OC.F as emersion at the end). More, they project their shadows on the disc of the planet and we observe the transit of the shadow of the satellite on the disc (O.C. or TR.D at the beginning and O.F. and TR.F at the end), and finally, they pass in front of the disc of the planet (P.C. or OM.D at the beginning and P.F. or OM.F at the end).
Because they are the farthest from Jupiter, the satellites Ganymede and Callisto, have no phenomena when the Sun is too high on the equatorial plane of Jupiter. The two satellites do not enter the shadow of Jupiter passing above or below.
These pages provide the predictions of the dates of the beginning and the end of all the phenomena chronologically, month by month. The timing provided corresponds to a drop of half the light flux of the satellites for the eclipses and the bissection of the disc of the satellite by the limb of the planet for the occultations or for the transits.
Notations
The dates of the predictions of these phenomena are given for every day (j) in hours (hh) and minutes (mm.m), to the nearest minute, except for the eclipses where the tenth of a minute is given. They are given on four columns. From 2024, more information is provided and explanations are given in the file of data.
j hhmm.m sat ph. j hhmm.m sat ph. j hhmm.m sat ph. j hhmm.m sat ph.
0 15 9 I P.C. 8 1216 II P.C. 15 1959 III O.F. 24 12 1 II IM. 0 1626 I O.C. 8 1355 III O.C. 24 1237 I IM. 0 1718 I P.F. 8 1418 I IM. 16 1327 I P.C. 24 1437 II EM. 0 1835 I O.F. 8 1447 II P.F. 16 1447 I O.C. 24 1446.9 II E.C. 8 1453 II O.C. 16 1537 I P.F. 24 16 7.0 I E.F. 1 430 III P.C. 8 1557 III O.F. 16 1656 I O.F. 24 1719.7 II E.F. 1 648 III P.F. 8 1722 II O.F. 1 944 II P.C. 8 1747.4 I E.F. 17 921 II IM. 25 952 I P.C. .../...
The satellites are designated in Roman numbers, I for Io, II for Europe, III for Ganymede and IV for Callisto. The different phases of the phenomena are designated as follows:
- E.C. and E.F. for eclipse, beginning and end,
- IM. and EM. for immersion and emersion (occultation) behind Jupiter,
- P.C. and P.F. for transit of the satellite in front of Jupiter, beginning and end,
- O.C. and O.F. for transit of its shadow on the disc of Jupiter, beginning and end.
From 2024, satellites were denoted 501 for Io, 502 for Europe, 503 for Ganymedes and 504 for Callisto. The codes became:
- EC.D and EC.F for eclipse, beginning and end,
- OC.D and OC.F for immersion or beginning of occultation and emersion or end of occultation by Jupiter,
- TR.D and TR.F for transit of the satellite in front of Jupiter, beginning and end,
- SH.D and SH.F for transit of the shadow of the satellite on the disc of Jupiter, beginning and end.
On figure 1, it is possible to see the positions of the satellites at the time of the following events: beginning of transit of Io (I P.C.), beginning of occultation of Europe (II IM.), end of eclipse of Ganymede (III E.F.), beginning of the transit of the shadow of Callisto (IV O.C.).
Time scale
the dates t of these phenomena is given in TT
(Terrestrial Time) which is close to TAI + 32.184 s) except for the years 2024 and 2025 provided in UTC. The dates tUT in the
time scale of the Universal Time may be obtained from t using:
tUT = t - (TT - TU) when the value of TT-TU is known.
It is the case for the past and current years through the table available here. For dates in the future, it is
possible to use the last value or a
parabolic extrapolation.
Observability
These predictions are given without taking into account the observability of the Jovian system. The observers will verify the local observing conditions thanks, for example, to the page on rising and setting of the solar system objects.
Sources
These predictions are made using the ephemerides of the Galilean satellites of Jupiter G-5 (Arlot, 1982) based upon the Sampson-Lieske's theory (Sampson 1921, Lieske, 1977) until 2012 then upon NOE-5-2021 (Lainey, 2004a et 2004b). The algorithm used for the prediction of the phenomena is described in (Thuillot, 1983, 1989, 1997) for events until 2022 and in (Thuillot, Arlot, 2021) after. More information is available in the following papers:
- Arlot, J.-E. : 1982, Astron. Astrophys. 107, 305
- Lainey, V. : 2004a, Astron. Astrophys. 420, 1171
- Lainey, V. : 2004b, Astron. Astrophys. 427, 371
- Lieske, J.H. : 1977, Astron. Astrophys., 56, 333
- Sampson, R.A. : 1921, Mem. Roy. Astron. Soc. 63,1
- Thuillot, W. : 1983, Astron. Astrophys. 127, 63
- Thuillot, W. : 1989, Prédictions des phénomènes des satellites galiléens. Note Scientifique et Technique du Bureau des longitudes S015, Bureau des longitudes, Paris.
- Thuillot, W. : 1997, Les phénomènes des satellites galiléens, Introduction aux éphémérides astronomiques - Supplément explicatif à la Connaissance des Temps, , EDP Science, 275-278
- Thuillot, W., Arlot, J.E. : 2021, Les phénomènes des satellites galiléens, Introduction aux éphémérides et phénomènes astronomiques - Supplément explicatif à la Connaissance des Temps, , EDP Science, p.661-682