3671 Dionysus
Binary Amor asteroid with a moon and Earth-grazing orbit.
3671 Dionysus is a small binary Amor asteroid that travels between Earth and the main asteroid belt. Discovered by Carolyn and Gene Shoemaker at Palomar Observatory on May 27, 1984, it was given the provisional designation 1984 KD and later named for the Greek god of wine. It is classified as an outer Earth grazer because its closest approach to the Sun falls just inside Earth's orbit.
The asteroid is considered a potentially hazardous object (PHA) because its minimum orbit intersection distance (MOID) with Earth is less than 0.05 AU and its diameter exceeds 150 meters. Its Earth-MOID is 0.01989 AU (about 2.98 million kilometers). The orbit is well understood for the next several hundred years. Dionysus makes modestly close passes by Earth: on June 19, 1984, it came within 0.0305 AU (roughly 4.56 million kilometers), and on June 18, 2085, it will pass at 0.028 AU (about 4.2 million kilometers).
In 1997, astronomers at the European Southern Observatory reported that lightcurve observations indicate a small moon orbits Dionysus. Designated S/1997 (3671) 1, this moon is about 300 meters in diameter and circles the asteroid at a distance of 3.6 km, with an orbital eccentricity of 0.07 and a period of 27.72 hours. From Dionysus's surface, the moon would appear about 3.02 degrees across—roughly six times the apparent size of the Sun as seen from Earth.
Quick Facts
- Minorplanet
- yes
- Background
- #FFC2E0
- Discoverer
- C. S. Shoemaker / E. M. Shoemaker
- Discovery Site
- Palomar Observatory
- Discovered
- 27 May 1984
- Mpc Name
- (3671) Dionysus
- Pronounced
- d · aɪ · ə · ˈ · n · aɪ · s · ə · s
- Adjective
- Dionysian d · aɪ · ə · ˈ · n · ɪ · s · i · ə · n
- Named After
- Διόνυσος Dionȳsos
- Mp Category
- PHA
- Epoch
- 13 January 2016 (JD 2457400.5)
- Aphelion
- 3.389527126 AU
Facts from the source article.
Lore & Background
3671 Dionysus was discovered by Carolyn and Gene Shoemaker at Palomar Observatory on 27 May 1984. It is named after Dionysus, the Greek god of wine. Its provisional designation was 1984 KD. It is classified as an outer Earth grazer because its perihelion lies just within Earth's orbit. The asteroid is considered a potentially hazardous object (PHA) because its minimum orbit intersection distance (MOID) with Earth is less than 0.05 AU and its diameter exceeds 150 meters. The Earth-MOID is 0.01989 AU (2,976,000 km; 1,849,000 mi). Its orbit is well-determined for the next several hundred years. Dionysus makes modestly close approaches to Earth: on 19 June 1984 it passed 0.0305 AU (4,560,000 km; 2,840,000 mi) from Earth, and on 18 June 2085 it will pass 0.028 AU (4,200,000 km; 2,600,000 mi) from Earth.
Reader's Guide
3671 Dionysus holds significance as a binary asteroid and a potentially hazardous object. Its binary nature was revealed in 1997 when a team of astronomers at the European Southern Observatory announced that lightcurve observations indicated the presence of a small moon, provisionally designated S/1997 (3671) 1. This moon measures 300 meters in diameter and orbits 3.6 km from Dionysus with an eccentricity of 0.07 and an orbital period of 27.72 hours. From the surface of Dionysus, the moon would have an apparent diameter of roughly 3.02 degrees, compared to the Sun's apparent diameter of 0.5° from Earth. As a PHA, its close approaches are monitored; its orbit is well-determined for several hundred years. The asteroid's classification as an outer Earth grazer and its binary system contribute to its interest for studies of near-Earth objects and asteroid dynamics.
Did You Know?
- 3671 Dionysus has a moon, S/1997 (3671) 1, discovered in 1997 via lightcurve observations.
- The moon orbits 3.6 km from Dionysus with an orbital period of 27.72 hours.
- Dionysus is an outer Earth grazer, meaning its perihelion lies just within Earth's orbit.
- On 18 June 2085, Dionysus will pass 0.028 AU (4,200,000 km) from Earth.
More in Notable Asteroids, Part 2 1-24
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