3671 Dionysus is a small binary Amor asteroid

Amor asteroid

The Amor asteroids are a group of near-Earth asteroids named after the asteroid 1221 Amor. They approach the orbit of the Earth from beyond, but do not cross it. Most Amors do cross the orbit of Mars...

, orbiting between the Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 and the asteroid belt

Asteroid belt

The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...

. It was discovered by Carolyn and Gene Shoemaker at Palomar Observatory

Palomar Observatory

Palomar Observatory is a privately owned observatory located in San Diego County, California, southeast of Pasadena's Mount Wilson Observatory, in the Palomar Mountain Range. At approximately elevation, it is owned and operated by the California Institute of Technology...

 on 27 May 1984. It is named after Dionysus

Dionysus

Dionysus was the god of the grape harvest, winemaking and wine, of ritual madness and ecstasy in Greek mythology. His name in Linear B tablets shows he was worshipped from c. 1500—1100 BC by Mycenean Greeks: other traces of Dionysian-type cult have been found in ancient Minoan Crete...

, the Greek god of wine. Its provisional designation was 1984 KD. It is an outer Earth grazer because its perihelion is within Earth's aphelion.

Dionysus is a B-type asteroid

B-type asteroid

B-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-group. In the asteroid population, B-class objects are abundant in the outer asteroid belt, and also dominate the high-inclination Pallas family which includes the second-largest asteroid 2 Pallas...

 and measures approximately 1.5km in diameter.

In 1997, a team of astronomers at the European Southern Observatory

European Southern Observatory

The European Southern Observatory is an intergovernmental research organisation for astronomy, supported by fifteen countries...

 announced that lightcurve observations indicate the presence of a small moon orbiting Dionysus. This moon measures 300 meters in diameter, and orbits 3.6km from Dionysus. It has received the provisional designation S/1997 (3671) 1.