The moon of Jupiter – Eurydome (XXXII) – was previously temporarily designated as S/2001 J4.
It was discovered in mid-December 2001 by the following team of astronomers: S.S. Sheppard
,
D.C. Jewitt
i J. Kleyna. This discovery was achieved by the 3.6-m Canada-France-Hawaii telescope atop Mauna Kea (Hawaii). You can read additional details in Minor Planet Electronic Circular (MPEC).
Eurydome is one of eleven new satellites discovered since the →Voyager-2
Jupiter system fly-by which occured 22 years ago (1979). With this moon, the
team discovered also: Autonoe, Thyone, Hermippe, Sponde,
Pasithee, Euanthe, Kale, Orthosie, Euporie and Aitne.
The name of that moon is of mythological origin. Eurydome was mother of the the Charites (gr. Chárites
– they were better known as the Roman Graces)
by Zeus as his forth wife. ,Eurydome's daughters was a personifications of charm
and joy. Most authors name three of them being the famous Three Graces: Euphrosyne
(''Mirth''), Aglaea (''Splendor'') and Thalia
(''Good Cheer''). They were often depicted in sculptures and paintings
as three naked beauties already since the Hellenistic Times...
The moon by this name is in elliptical retrograde orbit (→eccentricity
e = 0.2759) with a →semimajor axis a = 22,865,000 km. At pericenter (closest to the planet) Eurydome is separated from the Jupiter a distance of q = 16,556,547 km. At apocenter (furthest from the planet) this moon is separated from the Jupiter a distance of Q = 29,173,454 km.
In future these parameters may vary due to a large orbital distance from Jupiter and the orbital motion being disturbed by the Sun and other factors. Perhaps it is a captured asteroid (with a microscopic mass: ~4.4960×1013 kg – it equals
163 times less than a mountain like Giewont
!),
and in future will possibly return to heliocentric orbit.
The orbital period is a somewhat less than 2
earthly years, which means that the average speed of its celestial motion is
only 0°30'07'' per day. When this motion was detected and compared to the changes in Jupiter's position, this body was classified as a true planetary satellite (and not a distant celestial body with its position projected near the planet).
Other obstacle in detecting this moon earlier was its brightness of only 22.7m
(almost 4.8 million times fainter than the faintest stars visible to naked eye). For comparison: Jupiter's brightness is about –2.7m,
so Eurydome is shining fainter by about 25.4m.
The corresponding difference in brightness is over 14.5 billion times!
I have given some crucial data of Eurydome below. Table one
contains the basic information. Whereas table two gives more detailed parametrs
of its orbit (calculated using the following formulae).
Translated by Karol Pankowski
|
Eurydome
|
|---|
| Mean distance from the planet [×103 km] |
22,865.0
|
| Mean distance from the planet [planetary R] |
319.8
|
| Orbital period [days] |
717.33
|
| Orbital eccentricity [e] |
0.2759
|
| Orbit inclination [degrees] |
150.3
|
| Mean diameter [km] |
3.0
|
| Main discoverer and year of the discovery |
S.S. Sheppard 2001
|
| Visual magnitude [mag] |
22.7
|
| Mass [kg] |
~4.4960 × 1013
|
Orbital Parameters |
Pericenter
[q] |
Apocenter
[Q] |
| Distance from the planet [×103 km] |
16,556.5
|
29,173.5
|
| Distance from the planet [planetary R] |
231.6
|
408.1
|
| Angular size of the moon's orbit observed from the Earth* [degrees] |
1°30'32.01''
|
2°39'33.79''
|
|
| Angular diameter of the planet's disc as observed from the moon [degrees] |
0°29'41.33''
|
0°16'50.94''
|
| Brightness of the planet as observed from the moon** [mag] |
–10.6
|
–9.4
|
| Diameter of the moon's disc as observed from the planet's "surface" [degrees] |
0°00'00.04''
|
0°00'00.02''
|
| Brightness of the moon as observed from the planet's "surface"** [mag] |
14.8
|
16.0
|
|
Orbital velocity [km/sec] |
3.12
|
1.77
|
* This value is calculated for Jupiter at opposition (distance 628.8 million km = 4.2 AU)
** The given value of magnitude is not corrected for some decreasing factors (e.g. the changing phase of illumination)
|
See other related links:
Monde
des Monats
– PASIPHAEGRUPPE
Jupiter's 2002 Satellites
The Astronomy Workshop – Satellite Viewer
Planetary Satellite Mean Orbital Parameters
Natural Satellite Physical Parameters
