S / 2003 (130) 1
| (130) Elektra I (S / 2003 (130) 1) | |
|---|---|
| Provisional or systematic name | S / 2003 (130) 1 |
| Central body | (130) Electra |
| Properties of the orbit | |
| Major semi-axis | 1318 ± 25 km |
| Periapsis | 1146 km |
| Apoapsis | 1489 km |
| eccentricity | 0.13 ± 0.03 |
| Orbit inclination | 3.0 ± 1.0 ° |
| Orbital time | 5.2580 ± 0.0053 d |
| Physical Properties | |
| Albedo | ≈ 0.071 ± 0.011 |
| Apparent brightness | 14.5 mag |
| Medium diameter | 6.0 ± 1.5 km |
| Dimensions | ~ 4.0 · 10 14 kg |
| surface | 113 km 2 |
| Medium density | ≈ 1.3 ± 0.3 g / cm 3 |
| Surface temperature | 157 K |
| discovery | |
| Explorer |
|
| Date of discovery | August 15, 2003 |
| Remarks | Larger moon of the Elektra system |
S / 2003 (130) 1 is the outer and larger of the two moons of the main belt asteroid (130) Elektra . Its mean diameter is about 6 kilometers.
Discovery and naming
S / 2003 (130) 1 was published on August 15, 2003 by William J. Merline, Peter M. Tamblyn, Christophe Dumas, Laird M. Close, Clark R. Chapman and François Menard using adaptive optics with the 10 m Keck -Telescope II discovered on Mauna Kea in Hawaii . The discovery was announced two days later on August 17, 2003; the moon was given the provisional designation S / 2003 (130) 1 .
In 2016, the Very Large Telescope was discovered, a further companion from Elektra, which made the system the sixth known asteroid multiple system in the main belt and the tenth in total.
Track properties
S / 2003 (130) 1 orbits Elektra on a retrograde , elliptical orbit at an average distance of 1318 kilometers from its center (about 14.6 Elektra radii). The orbital eccentricity is 0.13, the orbit is inclined 3 ° with respect to the pole of Elektra . The orbit of the inner moon S / 2014 (130) 1 is on average about 858 km from the orbit of S / 2003 (130) 1.
S / 2003 (130) 1 orbits Elektra in 5 days, 6 hours and 11.5 minutes, which corresponds to about 384.7 orbits in one Elektra year (about 5.5 earth years). The orbit of S / 2003 (130) 1 is assumed to be stable, because it is well within Electra's Hill radius of 38,000 km, but also well outside the synchronous orbit.
Physical Properties
_1_by_SPHERE-VLT_2014.jpg)
According to current data, S / 2003 (130) 1 has a diameter of 6 km (about 1/30 of the central body), based on Electra's density and the corresponding assumed equal reflectivity of 7%. The surface is therefore extremely dark.
Assuming a mean diameter of 6 km, the surface area is about 113 km 2 , which roughly corresponds to the area of the German Müritz or the Swiss Lake Lucerne .
Determination of the diameter for S / 2003 (130) 1
| year | Dimensions km | source |
|---|---|---|
| 2003 | 4.0 | IAU |
| 2015 | 7.0 ± 3.0 | Johnson |
| 2016 | 6.0 ± 1.5 | Yang et al. |
The current determination is marked in bold .
internal structure
Since S / 2003 (130) 1 has a similar color to the mother body, it is assumed that the moon is made of the same material as Elektra and therefore has the same spectral type (G or Ch). Based on the same density and albedo, the mass could so far be calculated to be about 4 · 10 14 .
The mean surface temperature is around 157 K (−116 ° C) and can rise to a maximum of 251 K (−22 ° C) at noon; at night it can drop to 63 K (−210 ° C).
See also
Web links
- Wm. Robert Johnston: (130) Elektra, S / 2003 (130) 1, and S / 2014 (130) 1 (English)
- ESO: Elektra: A new triple asteroid with photo
Individual evidence
- ^ A b Daniel WE Green: IAUC No. 8183: S / 2003 (130) 1 discovery publication. Retrieved September 10, 2017 .
- ^ Wm. Robert Johnson: (130) Elektra, S / 2003 (130) 1, and S / 2014 (130) 1 (March 2015). Retrieved September 10, 2017 .
- ↑ Bin Yang et al .: Extreme AO Observations of Two Triple Asteroid Systems with SPHERE (March 2016). Retrieved September 10, 2017 .