(399307)
Asteroids with Satellites Database--Johnston's Archive
(399307) 1991 RJ2
compiled by Wm. Robert Johnston
last updated 17 January 2015
--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:_NEA, Amor _orbital data, primary (osculating elements)_[JPL] :semimajor axis **a:**2.2083582416 AUorbital period **P:**3.281740899 yr (= 1198.6785019 d)eccentricity **e:**0.428903368perihelion distance **q:**1.26118595 AUaphelion distance **Q:**3.1555305285 AUinclination **i:**8.9433021°argument of perihelion **ω:**150.817669°ascending node **Ω:**171.820039°mean anomaly **M:**37.125057°perihelion passage **TP:2014 Aug 07.386090Epoch:2014 Dec 09data arc:1991-2014 (206 obs.)Earth MOID:**0.262188 AUJupiter Tisserand invariant **TJ:**3.519 orbital data, secondary: semimajor axis **as:**0.86 km [*E]separation/primary radius **as/rp:**3.4 [*E]separation/Hill radius **as/rH:**0.017 [*E]orbital period **Ps:**0.66321 ± 0.00004 d [W15b]eccentricity es:?normalized ang. mom. αL:? | other data, system (combined): absolute mag. H:18.9 [MPC]slope parameter G: (0.15) [*A]effective diameter dE:0.55 km [*E]geometric albedo: (0.16 ) [*A]color index U-B:?color index B-V:?taxonomic type:?mass m:?density ρ: (1.6 g/cm3) [*A]Hill radius **rH:**51 km [*E] other data, primary: diameter **dp:**0.5 km [*E]rotation period **RPp:**3.4907 ± 0.0002 h [W15b]amplitude in mag., rotational **ΔM:**0.09 [W15b]amplitude in mag., mutual events **ΔM:**0.35 [W15b]pole direction Β, λ:? , ? other data, secondary: diameter **ds:**0.24 km [*E]axial ratios **a/b, b/c:**1.07;? [W15b] diameter ratio **ds/dp:**>0.47 ± 0.02 [W15b]component mag. difference ΔM:<1.64 [*D]rotation period **RPs:**15.917 ± 0.001 h [W15b] |
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-- (399307) 1991 RJ2 --discovery and notes:
Primary discovered 1991 Sep 08 from Palomar Observatory, California, USA by E. F. Helin. Permanent number assigned 2014 Jul 12.
Companion discovered 2014 Aug 27 by B. D. Warner, J. T. Pollock, D. E. Reichart, J. B. Haislip, A. P. LaCluyze, A. Verveer, T. Spuck, A. W. Harris using lightcurve observations from Palmer Divide Observatory, Colorado Springs, Colorado, USA; PROMPT Telescope, Chile; Perth Observatory, Australia. Announced 2014 Dec [W15b].
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--Links to ADS abstracts:
© 2015, 2014 by Wm. Robert Johnston.
Last modified 17 January 2015.
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