(8191) Mersenne Main-belt Asteroid

Discovered on 20 July 1993 by E. W. Elst at La Silla.

Named for Marin Mersenne (1588-1648), French mathematician and philosopher, best known for his discovery of prime numbers of the form 2n-1 and that n is then necessarily also prime. The number 8191 = 213-1 is the fifth Mersenne prime. Mersenne correctly verified that the numbers are prime also for n = 17, 19 and 31---and that they are not prime for n = 11, 23 and 29. The largest prime Mersenne correctly established was for n = 127. Name proposed by the discoverer, following a suggestion by B. G. Marsden, who wrote the citation.Naming citation (19980411/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL

Where Mersenne is today

Seen from above the solar system on 2026-10-14: Mersenne is 2.51 au from the Sun and 3.45 au from Earth. Computed from JPL's orbital elements.

Facts

Number	8191
Provisional designation	1993 OX9
Orbit class	Main-belt Asteroid
Diameter	2.89 km (#15,472 largest of 17,440 named asteroids with a measured size)
Albedo	0.306
Absolute magnitude (H)	14.89
Orbital period	3.40 years
Semi-major axis	2.26 au
Perihelion – aphelion	2.01 – 2.51 au
Eccentricity	0.110
Inclination	2.83°
Closest distance between its orbit and Earth's (MOID)	1.03 au

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

Also named after someone called Marin

All asteroids named after someone called Marin

Also discovered on 20 July 1993

More named asteroids discovered by E. W. Elst

All 1035

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