3996 Fugaku, provisional designation 1988 XG1, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 5.5 kilometers in diameter. It was discovered on 5 December 1988, by Japanese amateur astronomers Masaru Arai and Hiroshi Mori at Yorii Observatory in central Japan.[9] It was named for Mount Fuji, Japan.[2]
Discovery [1] | |
---|---|
Discovered by | M. Arai H. Mori |
Discovery site | Yorii Obs. |
Discovery date | 5 December 1988 |
Designations | |
(3996) Fugaku | |
Named after | Mount Fuji (Japan)[2] |
1988 XG1 · 1939 FZ 1957 TB · 1981 SO5 1981 UM16 | |
main-belt · Flora [3] | |
Orbital characteristics [1] | |
Epoch 4 September 2017 (JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 78.22 yr (28,570 days) |
Aphelion | 2.4941 AU |
Perihelion | 2.0254 AU |
2.2597 AU | |
Eccentricity | 0.1037 |
3.40 yr (1,241 days) | |
338.50° | |
0° 17m 24.36s / day | |
Inclination | 2.2842° |
90.755° | |
156.18° | |
Physical characteristics | |
Dimensions | 5.151±0.074 km[4] 5.231±0.032 km[5] 5.40 km (calculated)[3] 5.88±1.10 km[6] |
7.1912±0.0016 h[7] | |
0.24 (assumed)[3] 0.34±0.17[6] 0.4086±0.0152[5] 0.420±0.066[4] | |
S [3] | |
13.0[1][5][6] · 13.055±0.003 (R)[7] · 13.5[3] · 13.57±0.25[8] | |
Fugaku is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun in the inner main-belt at a distance of 2.0–2.5 AU once every 3 years and 5 months (1,241 days). Its orbit has an eccentricity of 0.10 and an inclination of 2° with respect to the ecliptic.[1] It was first identified as 1939 FZ at Turku Observatory in 1939, extending the asteroid's observation arc by 49 years prior to its official discovery observation.[9]
Fugaku has been characterized as a stony S-type asteroid, the most common type in the inner main-belt.[1]
In March 210, a rotational lightcurve of Fugaku was obtained from photometric observations at the Palomar Transient Factory in California. It gave a rotation period of 7.1912 hours with a change in brightness of 0.86 magnitude (U=2).[7]
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Fugaku measures between 5.15 and 5.88 kilometers in diameter, and its surface has an albedo between 0.34 and 0.42.[4][5][6] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the largest member and namesake of this family – and calculates a diameter of 5.40 kilometers with an absolute magnitude of 13.5.[3]
This minor planet was named for the ancient name of Mount Fuji, Japan's highest mountain and a well-known symbol. Another minor planet, 1584 Fuji, is also named for this mountain.[2] The official naming citation was published by the Minor Planet Center on 4 May 1999 (M.P.C. 34619).[10]