(4788)

Simpson (original) (raw)

Asteroids with Satellites Database--Johnston's Archive

(4788) Simpson

compiled by Wm. Robert Johnston
last updated 30 April 2022

--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:**2.2626167213 AUorbital period **P:**3.4034273812 yr (= 1243.1253289 d)eccentricity **e:**0.129443116perihelion distance **q:**1.969736563 AUaphelion distance **Q:**2.5554968799 AUinclination **i:**4.3187853°argument of perihelion **ω:**110.318461°ascending node **Ω:**277.176547°mean anomaly **M:**316.513479°perihelion passage **TP:2020 Oct 28.164432Epoch:2020 May 31data arc:1976-2020 (2088 obs.)Earth MOID:**0.979429 AUJupiter Tisserand invariant **TJ:**3.604 orbital data, secondary: semimajor axis **as:**5.7 km [*E]separation/primary radius **as/rp:**3.2 [*E]separation/Hill radius **as/rH:**0.011 [*E]orbital period **Ps:**0.6242 ± 0.0004 d [S21a]eccentricity es:?normalized ang. mom. αL:? other data, system (combined): absolute mag. **H:**13.7 [MPC]slope parameter G: (0.15) [*A]effective diameter dE:3.58 ± 0.70 km [M12b]geometric albedo:0.500 ± 0.174 [M12b]color index U-B:?color index B-V:?taxonomic type:?mass m:?density ρ: (1.6 g/cm3) [*A]Hill radius **rH:**540 km [*E] other data, primary: diameter **dp:**3.53 km [*D]rotation period **RPp:**2.81752 ± 0.00008 h [S21a]amplitude in mag., rotational **ΔM:**0.18 [S21a]amplitude in mag., mutual events **ΔM:**0.05 ±0.02 [S21a]pole direction Β, λ:? , ? other data, secondary: diameter **ds:**>0.6 km [*D]diameter ratio **ds/dp:**>0.17 [S21a]component mag. difference ΔM:<3.8 [S21a]rotation period RPs:?

-- (4788) Simpson --discovery and notes:

Primary discovered 1986 Oct 04 from Flagstaff, Arizona by E. Bowell. Alternate designation(s): 1986 TL1, 1976 YJ1, 1979 RN1, 1984 AS. Linked to prediscovery observations from 1976 Dec 16. Permanent number assigned 1991 Apr 28.

Named 1991 Jun 27 for Robert W. L. Simpson (1921-1997) [MPC018465].

Companion discovered 2020 Dec by P. Sogorb, et al. using lightcurve observations. Announced 2021 Jan 07 [S21a].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:

© 2021, 2022 by Wm. Robert Johnston.
Last modified 30 April 2022.
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