Peneius (moon)
| Peneius | |
|---|---|
| Provisional or systematic name | S / 2008 (41) 1 |
| Central body | (41) Daphne |
| Properties of the orbit | |
| Major semi-axis | 405 km |
| Periapsis | unknown |
| Apoapsis | unknown |
| Orbital time | 1.1 d |
| Physical Properties | |
| Medium diameter | <2 km |
| discovery | |
| Explorer |
|
| Date of discovery | March 28, 2008 |
| Remarks | Smallest diameter in relation to the mother asteroid |
Peneius (provisional designation S / 2008 (41) 1 ) is a moon of the main belt - asteroid (41) Daphne . Its estimated diameter is less than 2 kilometers. It has the smallest size ratio of all asteroid systems in the solar system .
Discovery and naming
Peneius was discovered on March 28, 2008 by a team of astronomers consisting of AR Conrad, William J. Merline, JD Drummond, PM Tamblyn, Christophe Dumas, BX Carry, RD Campbell, RW Goodrich, WM Owen and Clark R. Chapman during observations of (41 ) Daphne discovered using adaptive optics with the 10 m Keck Telescope II on Mauna Kea in Hawaii . At the time of discovery, Daphne was approximately 1.09 AU away and had an angular diameter of 0.22 ”.
The discovery was announced by the International Astronomical Union (IAU) on March 31, 2008, the moon was given the provisional designation S / 2008 (41) 1 . Unofficially, the moon was named Leucippos , after Leukippos from Greek mythology . On March 6, 2019, the Minor Planet Center announced that it had received the name Peneius, which is a Latinized form of the name of the Greek river god Peneios .
Track properties
Peneius orbits Daphne on a prograde orbit at a distance of 405 km from its center (around 4 Daphne radii) within 1.1 days, which corresponds to just under 3.2 rotations by Daphne. Originally a distance of 443 km was determined, which was later corrected down to 405 km. With that, the moon moves well within Daphne's Hill sphere of 31,000 km.
Peneius orbits Daphne in 26.4 hours, which corresponds to about 4.4 turns by Daphne.
Physical Properties
The diameter of Peneius is estimated to be less than 2 km. The discovery of the moon had no notable influence on the determination of the size of the mother asteroid, as it is currently estimated to have a size of around 205 km. Peneius therefore only has about 1.1% of the diameter of Daphne, which is the most extreme size ratio of all known asteroid systems in the solar system to date . If one also counts the four companions of the dwarf planet system Pluto / Charon as asteroid moons - Pluto is formally also listed as an asteroid - Peneius is surpassed by Styx (0.25%); In third place is the Pluto moon Kerberos with 1.2%.
If the Pluto moons are not counted, Daphne / Peneius follows the systems Camilla / S / 2016 (107) 1 (1.6%) and Alauda / Pichi üñëm (1.7%).
Peneius is 10 magnitudes fainter than Daphne, and the mass ratio is 1 to a million.
See also
Individual evidence
- ^ Daniel WE Green: IAUC No. 8930: S / 2008 (41) 1 Discovery Publication (2008). Retrieved September 1, 2017 .
- ↑ A: R. Conrad et al .: Asteroid (41) Daphne and its moon (2008) (PDF). Retrieved September 1, 2017 .
- ↑ Gareth V. Williams: MPEC 2019-E58: Satellite of (41) Daphne. Retrieved September 24, 2019 .
- ↑ WJ Merline et al .: Discovery of an extreme mass-ratio satellite of (41) Daphne in a close orbit (2008) (PDF). Retrieved September 1, 2017 .