(4951) Iwamoto

Asteroids with Satellites Database--Johnston's Archive

(4951) Iwamoto

compiled by Wm. Robert Johnston
last updated 21 September 2014

--Orbital and physical data--

(See this page for definitions of quantities; source codes in brackets, see this link for full references; *A, *D, and *E indicate assumed, derived, and estimated values, respectively.)

dynamical type, primary: main belt asteroid
orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 2.256428848 AU
orbital period P: 3.389539251 yr
(= 1238.029211 d)
eccentricity e: 0.166530009
perihelion distance q: 1.88066573 AU
aphelion distance Q: 2.632191963 AU
inclination i: 7.5280874°
argument of perihelion ω: 339.861910°
ascending node Ω: 101.089519°
mean anomaly M: 90.323691°
perihelion passage T_P: 2013 Jul 16.37953
Epoch: 2014 May 23
data arc: 1931-2014 (1168 obs.)
Earth MOID: 0.897826 AU
Jupiter Tisserand invariant T_J: 3.593

orbital data, secondary:

binary dynamical type: B [M09a]
semimajor axis a_s: 31 km [*E]
separation/primary radius a_s/r_p: 14 [*E]
separation/Hill radius a_s/r_H: 0.043 [*E]
orbital period P_s: 4.917 ± 0.008 d [R07b]
eccentricity e_s: ?
normalized ang. mom. α_L: 2.31 [M09a]

other data, system (combined):

absolute mag. H: 13.2 [MPC]
13.74 ± 0.06 [R07b]
slope parameter G: (0.15) [*A]
effective diameter d_E: 5.52 ± 0.03 km [M11b]
geometric albedo: 0.186 ± 0.032 [M11b]
color index U-B: ?
color index B-V: ?
taxonomic type: S (SMASSII) [JPL]
mass m: ?
density ρ: (1.6 g/cm³) [*A]
Hill radius r_H: 730 km [*E]
other data, primary:

diameter d_p: 4.39 ± 0.02 km [*D]
rotation period RP_p: 118.0 ± 0.2 h [R07b]
amplitude in mag., rotational ΔM: 0.34 [R07b]
pole direction Β, λ: ? , ?

other data, secondary:

diameter d_s: 3.34 km [*D]
diameter ratio d_s/d_p: >0.76 [R07b]
component mag. difference ΔM: <0.60 [*D]
rotation period RP_s: 118.0 ± 0.2 h [R07b]

-- (4951) Iwamoto --discovery and notes:

Primary discovered 1990 Jan 21 from Kani, Japan by Y. Mizuno and T. Furuta. Alternate designation(s): 1990 BM, 1931 UQ, 1985 QN6, 1985 RH5, 1989 WS3. Linked to prediscovery observations from 1931 Oct 17. Permanent number assigned 1991 Sep 23.

Named 1996 Mar 05 for Masayuki Iwamoto (1954-) [MPC26763].

Companion discovered 2007 May 11 by V. Reddy, R. Dyvig, P. Pravec, P. Kusnirak, A. Galad, L. Kornos, S. Gajdos, J. Vilagi, D. Pray, W. Cooney, J. Gross, D. Terrell, Yu. Krugly, J. Ries, K. Archer, J. Oey, M. Pikler, M. Husarik, R. Durkee, F. Colas, and A. Harris using lightcurve observations from University of North Dakota, Grand Forks; Badlands Observatory, Quinn, South Dakota, USA; Ondrejov Observatory, Czech Republic; Modra Observatory, Slovakia; Carbuncle Hill Observatory, Greene, Rhode Island, USA; Sonoita Research Observatory, Sonoita, Arizona, USA; Kharkiv Observatory, Ukraine; McDonald Observatory, Texas, USA; Ironwood Observatory, Oahu, Hawaii, USA; Leura, New South Wales, Australia; Skalnate Pleso Observatory; Shed of Science Observatory, Minneapolis, Minnesota, USA; Pic du Midi Observatory; Space Science Institute. Announced 2007 May 11 [R07b].

--Links, more technical:

IAUC 8836

--Links, less technical:

Kleinplaneten-Doppel.

--Links to ADS abstracts:

Reddy, V., Dyvig, R., Pravec, P., Kusnirak, P., Galad, A., Kornos, L., Gajdos, S., Vilagi, J., Pray, D., Cooney, W., Gross, J., Terrell, D., Krugly, Yu., Ries, J., Archer, K., Oey, J., Pikler, M., Husarik, M., Durkee, R., Colas, F., & Harris, A. 2007, International Astronomical Union Circular (4951) Iwamoto
Bus, S. & Binzel, R. P. 2004, NASA Planetary Data System 4951 Iwamoto CCD Spectrum

© 2007-2008, 2014 by Wm. Robert Johnston.
Last modified 21 September 2014.
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