| Discovery[1] | |
|---|---|
| Discovered by | M. Yanai K. Watanabe |
| Discovery site | Kitami Obs. |
| Discovery date | 15 August 1988 |
| Designations | |
| (3915) Fukushima | |
Named after | Hisao Fukushima (Japanese amateur astronomer)[2] |
| 1988 PA1 · 1926 GQ 1935 UL · 1935 UX 1950 QT · 1975 EX5 1977 TV7 · 1977 TW3 1979 FH1 · 1983 EM | |
| main-belt · (inner)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 91.05 yr (33,256 days) |
| Aphelion | 2.5392AU |
| Perihelion | 2.3394 AU |
| 2.4393 AU | |
| Eccentricity | 0.0410 |
| 3.81yr (1,392 days) | |
| 238.57° | |
| 0° 15m 31.32s / day | |
| Inclination | 14.431° |
| 173.51° | |
| 143.54° | |
| Physical characteristics | |
| Dimensions | 20.38±1.6 km(IRAS:9)[4] 21.993±0.052[5] 22.354±0.031 km[6] 22.82±0.38 km[7] |
| 8.40±0.01h[8] 9.41±0.01 h[9] 9.4177±0.0004 h[10] 9.418±0.001 h[11] | |
| 0.0441±0.0015[6] 0.046±0.002[7] 0.051±0.002[5] 0.0561±0.010(IRAS:9)[4] | |
| P[6] · C[3] | |
| 12.2[3][4][6][7] · 12.3[1] | |
3915 Fukushima, provisional designation1988 PA1, is a carbonaceousasteroid from the inner regions of theasteroid belt, approximately 21 kilometers in diameter.
It was discovered on 15 August 1988, by Japanese astronomersMasayuki Yanai andKazuro Watanabe at theKitami Observatory in eastern Hokkaido, Japan, and named after amateur astronomerHisao Fukushima.[2][12]
Fukushima orbits the Sun in theinner main-belt at a distance of 2.3–2.5 AU once every 3 years and 10 months (1,392 days). Its orbit has aneccentricity of 0.04 and aninclination of 14° with respect to theecliptic.[1] The asteroid was first identified as1926 GQ atHeidelberg Observatory in 1926, extending the body'sobservation arc by 62 years prior to its official discovery observation at Kitami.[12]
Fukushima has been characterized as a reddishP-type asteroid by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer.[6] It is also an assumedC-type asteroid.[3]
Several high-quality rotationallightcurves were obtained from photometric observations since 2003. An observation byBrian D. Warner at the U.S. Palmer Divide Observatory in Colorado rendered arotation period of9.418±0.001 hours with a high brightness variation of 0.67 in magnitude (U=3), indicating that the body has a non-spherical shape.[11] This observation concurs with another measurement taken at theOakley Observatory that rendered a period of9.41±0.01 and an amplitude of 0.50 mag (U=3),[9] superseding a less accurate lightcurve produced by the PDS of 8.40 hours (U=2).[8] In 2011, an observation by René Roy gave another concurring period of9.4177±0.0004 hours and an amplitude of 0.79 mag (U=3).[10] On 16 December 2012, the asteroid occulted the star HIP 4315 over parts of Europe and North America. At the time the body's brightness was 16.3 inmagnitude (mag) and that of the star was 8.5 mag.[13]
According to the space-based surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and the NEOWISE mission, the asteroid has a lowalbedo in the range of 0.044 and 0.056 with a diameter between 20.3 and 22.8 kilometers.[4][5][6][7] TheCollaborative Asteroid Lightcurve Link gives preference to the results obtained by IRAS with an albedo of 0.0561 and a diameter of 20.38 kilometers.[3]
Thisminor planet was named in honor of Japanese researcher and amateur astronomer, Hisao Fukushima (1910–1997), known for his research in hydrodynamics. He was professor emeritus atHokkaido University, and, as an activeamateur astronomer, a member of theHokkaido Astronomical Liaison Group.[2] The approved naming citation was published by theMinor Planet Center on 23 December 1988 (M.P.C. 14030).[14]
