Remus (moon)
- F. Marchis
- P. Descamps
- D. Hestroffer
- J. Berthier
Remus is the inner and smaller of the two moons of main belt asteroid (87 ) Sylvia ( Cybele group). Its average diameter is about 7 kilometers, which corresponds to about 1/40 of Sylvia diameter.
Discovery and designation
Remus was on August 9, 2004 by Franck Marchis ( University of California, Berkeley ), Pascal Descamps, Daniel Hestroffer and Jérôme Berthier ( Observatoire de Paris ) with the VLT 8.2 -m telescope of the European Southern Observatory Yepun on Cerro Paranal in Chile discovered. The project Marchis waited with the data processing, as he waited for the completion of a new image processing program. He received shortly before his scheduled vacation trip in March 2005 by Pascal Descamps a little note with the title " 87 Sylvia is three times? " By which this was to suggest that he could make out on several images of Sylvia two companions. The whole team went out immediately to the analysis of the data, sent a treatise on the Asteroid Comet Meteor Conference in August in Armacao dos Buzios near Rio de Janeiro and sent the same day a name proposed to the International Astronomical Union ( IAU). The discovery was announced almost exactly a year after the discovery on 10 August 2005; the moon was given the provisional designation S/2004 (87 ) 1 The discovery was made by the system for the first known triple asteroid system.
On August 11, both moons were officially named. Since Sylvia was named after Rhea Silvia, suggested the team to Franck Marchis, to name the two satellites by Sylvia- Romulus and Remus, the children of Rhea Sylvia and the god Mars, were raised by a she-wolf. In Roman mythology, Romulus killed his twin brother Remus in a quarrel, when it came, after whom the newly founded city of Rome should now be named.
Web properties
Remus surrounded Sylvia on a prograde, nearly perfect circular orbit at an average distance of 706 kilometers to the center, which corresponds to less than 5 Sylvia radii. The orbital eccentricity is not more than 0.016, the orbit is inclined 2.0 ° relative to the equator of Sylvia. The orbit of the outer moon Romulus ' Orbit removed on average about 650 km from Remus.
Remus surrounded Sylvia in 1 days, 9 hours and 5.5 minutes, resulting in a Sylvia- year corresponds to approximately 1,727.4 rounds (about 6.52 Earth years ). From the orbit of Remus is assumed that it is stable, because it is well within Sylvia's Hill sphere ( about 1/100 of the Hill radius of Sylvia ), but also far outside the synchronous orbit.
Physical Properties
The result, the system is probably due to a collision of two asteroids. From the large fragments of such a collision is accordingly formed the great mother asteroid, during the moons probably smaller debris are the collision that were attracted by the new asteroid. Remus is therefore as the parent body of the type Rubble Pile.
Research
Since the discovery in 2004 Remus could only be observed by ground-based telescopes, while its orbital elements are determined. If the mode of origin of the system confirm the group to Franck Marchis anticipates the discoveries of triple systems in the main belt are piling up. So far (as of May 2010) are those known five.
From the surface of the parent body Remus Sylvia seems huge, it would cover an area of approximately 30 ° by 18 °, while the size of the second companion Romulus varies between 1.6 ° and 0.5 °.