Asteroids with Satellites Database--Johnston's Archive

(1934) Jeffers

compiled by Wm. Robert Johnston
last updated 25 September 2021

--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: 2.3909566121 AU
orbital period P: 3.6970688869 yr
(= 1350.3799145 d)
eccentricity e: 0.298857051
perihelion distance q: 1.67640237 AU
aphelion distance Q: 3.105510854 AU
inclination i: 23.1451024°
argument of perihelion ω: 294.754438°
ascending node Ω: 86.4978789°
mean anomaly M: 80.8982921°
perihelion passage TP: 2020 Aug 31.546031
Epoch: 2021 Jul 01
data arc: 1961-2021 (2745 obs.)
Earth MOID: 0.7964 AU
Jupiter Tisserand invariant TJ: 3.366


orbital data, secondary:
semimajor axis as: 15 km [*E]
separation/primary radius as/rp:3.2 [*E]
separation/Hill radius as/rH:0.012 [*E]
orbital period Ps: 0.6256 ± 0.0002 d [P21i]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 12.53 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 9.24 ± 0.1 km [M**]
geometric albedo: 0.245 ± 0.047 [M**]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 1200 km [*E]

other data, primary:
diameter dp: 9.24 ± 0.1 km [M**]
rotation period RPp: 6.0427 ± 0.002 h [P21i]
amplitude in mag., rotational ΔM: 0.15 [P21i]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: ?
diameter ratio ds/dp: ?
component mag. difference ΔM: ?
rotation period RPs: ?

-- (1934) Jeffers --discovery and notes:

Primary discovered 1972 Dec 02 from Mount Hamilton by A. R. Klemola. Alternate designation(s): 1972 XB, 1951 AN1, 1961 YA, 2019 GT25. Linked to prediscovery observations from 1961 Dec 31. Permanent number assigned -.

Named 1976 Feb 20 for Hamilton M. Jeffers (1893-1976) [MPC003938].

Companion discovered 2020 Dec 19 by P. Pravec et al. using lightcurve observations from Astronomical Observatory of the University of Siena; Sugarloaf Mountain Observatory, South Deerfield, Massachusetts, USA; Skalnate Pleso Observatory; Shed of Science South Observatory, Pontotoc, Texas, USA; Blue Mountains Observatory, Leura, New South Wales, Australia. Announced 2021 Jan [P21h].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2021 by Wm. Robert Johnston.
Last modified 25 September 2021.
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