The moon of Jupiter – S/2003
J19 – was discovered in April 2003 by B. Gladman
.
This discovery was achieved by the 3.6-m Canada-France-Hawaii telescope atop Mauna Kea (Hawaii). You can read additional details in The International Astronomical Union Circular
(→IAU).
S/2003 J19 is one of two new satellites Jupiter's new satellites
discovered since the →Voyager-2
Jupiter system fly-by which occured 24 years ago (1979). With this moon, the
astronomer discovered also Carpo.
The moon is in elliptical retrograde orbit (→eccentricity
e = 0.2559) with a →semimajor axis a = 23,535,000 km. At pericenter (closest to the planet) S/2003 J19 is separated from the Jupiter a distance of q = 17,512,394 km. At apocenter (furthest from the planet) this moon is separated from the Jupiter a distance of Q = 29,557,607 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: ~1.4987×1013 kg – it equals 490 times
less than a mountain like Giewont
!),
and in future will possibly return to heliocentric orbit.
The orbital period is over 2 earthly years, which means that the average speed of its celestial motion is
only 0°29'10'' 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 23.7m
(over 12 million times fainter than the faintest stars visible to naked eye). For comparison: Jupiter's brightness is about –2.7m,
so S/2003 J19 is shining fainter by about 26.4m.
The corresponding difference in brightness is over 36 billion times!
I have given some crucial data of S/2003 J19 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
|
S/2003 J19
|
|---|
| Mean distance from the planet [×103 km] |
23,535.0
|
| Mean distance from the planet [planetary R] |
329.2
|
| Orbital period [days] |
740.43
|
| Orbital eccentricity [e] |
0.2559
|
| Orbit inclination [degrees] |
165.2
|
| Mean diameter [km] |
2.0
|
| Main discoverer and year of the discovery |
B. Gladman 2003
|
| Visual magnitude [mag] |
23.7
|
| Mass [kg] |
~1.4987 × 1013
|
Orbital Parameters |
Pericenter
[q] |
Apocenter
[Q] |
| Distance from the planet [×103 km] |
17,512.4
|
29,557.6
|
| Distance from the planet [planetary R] |
245.0
|
413.4
|
| Angular size of the moon's orbit observed from the Earth* [degrees] |
1°35'45.69''
|
2°41'39.95''
|
|
| Angular diameter of the planet's disc as observed from the moon [degrees] |
0°28'04.10''
|
0°16'37.80''
|
| Brightness of the planet as observed from the moon** [mag] |
–10.5
|
–9.3
|
| Diameter of the moon's disc as observed from the planet's "surface" [degrees] |
0°00'00.02''
|
0°00'00.01''
|
| Brightness of the moon as observed from the planet's "surface"** [mag] |
15.9
|
17.1
|
|
Orbital velocity [km/sec] |
3.01
|
1.79
|
* 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:
AstroNEWS
– "Five dozen of the Jupiter's moons"
Monde
des Monats
– CARMEGRUPPE
New
Satellites of Jupiter 2003
The Astronomy Workshop – Satellite Viewer
Planetary
Satellite Mean Orbital Parameters
Natural
Satellite Physical Parameters
