3671 Dionysus is a small binary

Amor asteroid The Amor asteroids are a group of near-Earth asteroids named after the archetype object 1221 Amor . The orbital perihelion of these objects is close to, but greater than, the orbital aphelion of Earth (i.e., the objects do not cross Earth's orbi ...

, orbiting between

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

and the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, c ...

. It was discovered by Carolyn and

Gene Shoemaker Eugene Merle Shoemaker (April 28, 1928 – July 18, 1997) was an American geologist. He co-discovered Comet Shoemaker–Levy 9 with his wife Carolyn S. Shoemaker and David H. Levy. This comet hit Jupiter in July 1994: the impact was televis ...

at Palomar Observatory on 27 May 1984. It is named after

Dionysus In ancient Greek religion and myth, Dionysus (; grc, Διόνυσος ) is the god of the grape-harvest, winemaking, orchards and fruit, vegetation, fertility, insanity, ritual madness, religious ecstasy, festivity, and theatre. The Roma ...

, the

Greek god The following is a list of gods, goddesses, and many other divine and semi-divine figures from ancient Greek mythology and ancient Greek religion. Immortals The Greeks created images of their deities for many purposes. A temple would house the ...

of wine. Its

provisional designation Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been cal ...

was 1984 KD. It is an outer Earth grazer because its perihelion is just within Earth's orbit.

Potentially hazardous object

3671 Dionysus is a

potentially hazardous asteroid A potentially hazardous object (PHO) is a near-Earth object – either an asteroid or a comet – with an orbit that can make close approaches to the Earth and is large enough to cause significant regional damage in the event of impact. They are ...

(PHA) because its

minimum orbit intersection distance Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits o ...

(MOID) is less than 0.05 AU and its diameter is greater than 150 meters. The Earth-MOID is . Its orbit is well-determined for the next several hundred years. Dionysus makes modestly close approaches to Earth. On 19 June 1984 Dionysus passed from Earth. On 18 June 2085 it will pass from Earth.

Moon

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

lightcurve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular freq ...

observations indicate the presence of a small moon orbiting Dionysus. Its provisional designation is S/1997 (3671) 1. This moon measures 300 meters in diameter, and orbits 3.6 km from Dionysus with an

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.07 and an

orbital period The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...

of 27.72 hours.Johnston's Archive: (3671) Dionysus and S/1997 (3671) 1
/ref> From the surface of Dionysus, S/1997 (3671) 1 would have an apparent diameter of roughly 3.02 degrees.Calculated by solving the equation

\scriptstyle

. For comparison, the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

appears to be 0.5° from Earth.

Notes

References

External links

Asteroids with Satellites
Robert Johnston, johnstonsarchive.net * * * {{DEFAULTSORT:Dionysus 003671 Discoveries by Eugene Merle Shoemaker Discoveries by Carolyn S. Shoemaker Named minor planets 003671 003671 003671 19840527