| Discovery [1] | |
|---|---|
| Discovered by | Y. Mizuno T. Furuta |
| Discovery site | Kani Obs. ( 403 ) |
| Discovery date | 21 January 1990 |
| Designations | |
| (4951) Iwamoto | |
Named after | Masayuki Iwamoto (Japanese astronomer) [2] |
| 1990 BM ·1931 UQ 1985 QN6 ·1985 RH5 1989 WS3 | |
| main-belt ·(inner) [3] | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 85.45 yr (31,210 days) |
| Aphelion | 2.6318 AU |
| Perihelion | 1.8824 AU |
| 2.2571 AU | |
| Eccentricity | 0.1660 |
| 3.39 yr (1,239 days) | |
| 79.093° | |
| 0° 17m 26.52s / day | |
| Inclination | 7.5269° |
| 101.08° | |
| 339.95° | |
| Known satellites | 1 [4] [lower-alpha 1] (≥ 0.76 Ds/Dp; P: 118 h) |
| Physical characteristics | |
| Dimensions | 4.39±0.02 km [4] 5.192±0.043 km [5] 5.515±0.033 km [6] 5.528 km (revised WISE) [7] 5.53 km (taken) [3] |
| 118 h [8] 118.0±0.2 h [lower-alpha 2] | |
| 0.1844(revised WISE) [7] 0.1859±0.0324 [6] 0.218±0.038 [5] | |
| SMASS = S [1] · S [3] V–R = 0.480±0.030 [lower-alpha 2] | |
| 13.3 [1] ·13.74±0.06 [3] [7] [lower-alpha 2] ·13.74 [6] ·14.01±1.40 [9] | |
4951 Iwamoto, provisional designation 1990 BM, is a stony, synchronous binary [lower-alpha 1] asteroid and slow rotator from the inner regions of the asteroid belt, approximately 5.5 kilometers in diameter. It was discovered on 21 January 1990, by Japanese astronomers Yoshikane Mizuno and Toshimasa Furuta at Kani Observatory ( 403 ) in Japan. [10]
Iwamoto orbits the Sun in the inner main-belt at a distance of 1.9–2.6 AU once every 3 years and 5 months (1,239 days). Its orbit has an eccentricity of 0.17 and an inclination of 8° with respect to the ecliptic. [1] It was first identified as 1931 UQ at Lowell Observatory in 1931, extending the body's observation arc by 59 years prior to its official discovery observation at Kani. [10]
In the SMASS classification, Iwamoto is a common S-type asteroid. [1]
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Iwamoto measures 5.192 and 5.515 kilometers in diameter, and its surface has an albedo of 0.218 and 0.186, respectively. [6] [5] The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-data, that is, an albedo of 0.1844 and a diameter of 5.528 kilometers with on an absolute magnitude of 13.74. [3] [7]
From 25 December 2006 to 23 March 2007, photometric observations of Iwamoto were obtained by the international community of photometrists at Badlands Observatory (SD, USA), Ondřejov Observatory (Czech Republic), Modra Observatory (Slovakia), Carbuncle Hill Observatory (RI, USA), Sonoita Research Observatory (AZ, USA), Kharkiv Observatory (Ukraine), McDonald Observatory (TX, USA), Ironwood Observatory (HI, USA), Leura Observatory (Australia), Skalnaté pleso Observatory (Slovakia), Shed of Science Observatory (MN, USA), Pic du Midi Observatory (France). [lower-alpha 1]
Lightcurve analysis gave a rotation period of 118 hours with a brightness variation of 0.34 magnitude ( U=3 ). [lower-alpha 2] In May 2011, astronomers Etienne Morelle, Raoul Behrend obtained another lightcurve with a concurring period of 118 hours and an amplitude of 0.38 magnitude.( U=3 ). [8] With such a long period, Iwamoto is also a slow rotator, as the vast majority of asteroids have a much shorter rotation period of 2.2 to 20 hours.
During the photometric observations in 2006/7, it was revealed that Iwamoto ("primary") is a synchronous binary system with a minor-planet moon ("secondary") orbiting it every 4.917 days (or 118 hours, which identical to the primary's rotation). Based on the secondary-to-primary mean-diameter ratio (Ds/Dp) of at least 0.76, it was estimated that Iwamoto and its moon measure 4.0 and 3.5 kilometers, respectively. [lower-alpha 2] The diameter of Iwamoto has since increased to 5.5 kilometers (see above). The "Jonstonarchive" estimates that the moon has a semi-major axis of 31 kilometers. [4]
This minor planet was named in honor of Japanese astronomer Masayuki Iwamoto (born 1954), a discoverer of minor planets at the Tokushima Observatory ( 872 ). [2] The approved naming citation was published by the Minor Planet Center on 5 March 1996 ( M.P.C. 26763). [11]
1509 Esclangona, provisional designation 1938 YG, is a rare-type Hungaria asteroid and binary system from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It is named after French astronomer Ernest Esclangon.
11264 Claudiomaccone, provisional designation 1979 UC4, is a stony background asteroid and binary system from the middle regions of the asteroid belt, approximately 3 kilometers in diameter. It was discovered 16 October 1979, by Nikolai Chernykh at Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula. It was named after the Italian astronomer Claudio Maccone.
2006 Polonskaya (provisional designation: 1973 SB3) is a stony Flora asteroid and asynchronous binary system from the inner regions of the asteroid belt, approximately 5 kilometers (3.1 miles) in diameter. It was discovered on 22 September 1973, by Soviet astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula, and later named after Ukrainian astronomer Elena Kazimirtchak-Polonskaïa. Its one-kilometer-sized satellite was discovered by an international collaboration of astronomers in November 2005.
3309 Brorfelde, provisional designation 1982 BH, is a nearly spheroidal, binary Hungaria asteroid from the inner regions of the asteroid belt, approximately 4 kilometers in diameter. It was discovered on 28 January 1982, by Danish astronomers Kaare Jensen and Karl Augustesen at the Brorfelde Observatory near Holbæk, Denmark. It was named for the discovering observatory and the village where it is located.
3673 Levy, provisional designation 1985 QS, is a binary Flora asteroid from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 22 August 1985, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station near Flagstaff, Arizona, United States. The asteroid was named after Canadian astronomer David H. Levy.
1717 Arlon, provisional designation 1954 AC, is a binary Florian asteroid from the inner regions of the asteroid belt, approximately 8.5 kilometers in diameter.
6084 Bascom, provisional designation 1985 CT, is a binary Phocaea asteroid from the inner regions of the asteroid belt, approximately 6.3 kilometers in diameter. It was discovered on 12 February 1985, by American astronomer couple Carolyn and Eugene Shoemaker at Palomar Observatory in California. It is named after American geologist Florence Bascom. Its satellite measures approximately 2.3 kilometers and has an orbital period of 43.51 hours.
4029 Bridges, provisional designation 1982 KC1, is a stony asteroid and binary system from the middle regions of the asteroid belt, approximately 8 kilometers in diameter.
1338 Duponta, provisional designation 1934 XA, is a stony Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 7.8 kilometers in diameter.
1453 Fennia, provisional designation 1938 ED1, is a stony Hungaria asteroid and synchronous binary system from the innermost regions of the asteroid belt, approximately 7 kilometers in diameter. Discovered by Yrjö Väisälä at the Turku Observatory in 1938, the asteroid was later named after the Nordic country of Finland. The system's minor-planet moon was discovered in 2007. It has a derived diameter of 1.95 kilometers and is orbiting its primary every 23.55 hours.
5474 Gingasen, provisional designation 1988 XE1, is a Vestian asteroid and suspected binary system from the inner regions of the asteroid belt, approximately 6 kilometers in diameter.
7225 Huntress, provisional designation 1983 BH, is a binary Florian asteroid from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 22 January 1983, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station in Flagstaff, Arizona, United States. It is named after astrochemist Wesley Huntress.
5905 Johnson, provisional designation 1989 CJ1, is a Hungaria asteroid and synchronous binary system from the innermost regions of the asteroid belt, approximately 4 kilometers (2.5 miles) in diameter. It was discovered on 11 February 1989, by American astronomer Eleanor Helin at Palomar Observatory in California, United States. Its satellite measures approximately 1.6 km (1 mi) in diameter and orbits its primary every 21.8 hours. It was named after American astronomer and engineer Lindley N. Johnson.
5481 Kiuchi, provisional designation 1990 CH, is a bright binary Vestian asteroid from the inner regions of the asteroid belt, approximately 4 kilometers in diameter. It was discovered on 15 February 1990, by Japanese astronomers Kin Endate and Kazuro Watanabe at Kitami Observatory in Hokkaidō, Japan, and named after their colleague Tsuruhiko Kiuchi. The V-type asteroid has a rotation period of 3.6 hours.
2815 Soma, provisional designation 1982 RL, is a binary Florian asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 15 September 1982, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station in Flagstaff, Arizona, in the United States. It is named for the mechanical puzzle Soma cube.
4786 Tatianina, provisional designation 1985 PE2, is a bright background asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 3.4 kilometers (2.1 miles) in diameter. It was discovered on 13 August 1985, by Soviet astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula. It was named after Tatiana Somova, a friend of the discoverer. The E-/Xc-subtype has a short rotation period of 2.9 hours. Its sub-kilometer minor-planet moon was discovered on 20 March 2006 and announced the following month.
3982 Kastelʹ, provisional designation 1984 JP1, is a Florian asteroid and a suspected binary system from the inner regions of the asteroid belt, approximately 6.9 kilometers in diameter.
10208 Germanicus, provisional designation 1997 QN1, is a stony Florian asteroid and binary system from the inner regions of the asteroid belt, approximately 3.5 kilometers in diameter.
20325 Julianoey, provisional designation 1998 HO27, is a Vestian asteroid and a synchronous binary system from the inner regions of the asteroid belt, approximately 5 kilometers (3 miles) in diameter. It was discovered on 21 April 1998, by astronomers of the Spacewatch survey at Kitt Peak National Observatory near Tucson, Arizona. The asteroid was named after Australian photometrist Julian Oey. The discovery of its minor-planet moon was announced in December 2014.
(15700) 1987 QD, provisional designation 1987 QD, is a Mars-crossing asteroid and a binary candidate from inside the innermost region of the asteroid belt, approximately 3 kilometers in diameter. It was discovered on 24 August 1987, by American astronomer Stephen Singer-Brewster at the Palomar Observatory in California. The likely spherical X-type asteroid has a rotation period of 3.1 hours. The suspected presence of a kilometer-sized minor-planet moon was announced in November 2000.
