(6639) Marchis Main-belt Asteroid

Discovered on 25 September 1989 by H. Debehogne at La Silla.

Franck Marchis (b. 1973) exploited the high-resolution capabilities offered by adaptive optics from ground-based telescopes to survey hundreds of main-belt minor planets and Trojans. In 2004 he led the team that discovered (87) Sylvia II (Remus), the only case where a main-belt object is known to have a second satellite.Naming citation (20070402/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL

Where Marchis is today

Seen from above the solar system on 2026-10-14: Marchis is 3.35 au from the Sun and 4.24 au from Earth. Computed from JPL's orbital elements.

Facts

Number	6639
Provisional designation	1989 SO8
Orbit class	Main-belt Asteroid
Diameter	14.1 km (#3,366 largest of 17,440 named asteroids with a measured size)
Albedo	0.0640
Rotation period	59.8 hours
Absolute magnitude (H)	12.88
Orbital period	5.64 years
Semi-major axis	3.17 au
Perihelion – aphelion	2.74 – 3.60 au
Eccentricity	0.136
Inclination	2.50°
Closest distance between its orbit and Earth's (MOID)	1.72 au

Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.

Also named after someone called Franck

All asteroids named after someone called Franck

Also discovered on 25 September 1989

(8357) O'Connor

More named asteroids discovered by H. Debehogne

All 203

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