(3918) Brel

--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: 2.24416164593 AU orbital period P: 3.3619357229 yr (= 1227.9470228 d) eccentricity e: 0.20812155423 perihelion distance q: 1.7771032362 AU aphelion distance Q: 2.71122005561 AU inclination i: 7.510621421° argument of perihelion ω: 203.0187523° ascending node Ω: 160.62000266° mean anomaly M: 14.10311037° perihelion passage TP: 2025 Oct 03.8947989 Epoch: 2025 Nov 21 data arc: 1931-2025 (5339 obs.) Earth MOID: 0.775678 AU Jupiter Tisserand invariant TJ: 3.592 orbital data, secondary: semimajor axis as: 11 km [*E] separation/primary radius as/rp: 3.5 [*E] separation/Hill radius as/rH: 0.012 [*E] orbital period Ps: 0.69396 ± 0.00029 d [D25d] eccentricity es: ? normalized ang. mom. αL: ?

other data, system (combined): absolute mag. H: 12.8 [MPC] slope parameter G: (0.15) [*A] effective diameter dE: 6.29 ± 0.13 km [M19a] geometric albedo: 0.289 ± 0.018 [M19a] color index U-B: ? color index B-V: ? color index J-H: 0.501 ± 0.08 [S10b] taxonomic type: ? mass m: ? density ρ: (1.6 g/cm3) [*A] Hill radius rH: 850 km [*E] other data, primary: diameter dp: 6.14 ± 0.13 km [*D] dimensions : ~6.9 x ~5.4 km [*E] axial ratios a/b, b/c: 1.3, ? [*E] rotation period RPp: 3.097 ± 0.0003 h [D25d] amplitude in mag., rotational ΔM: 0.26 [D25d] amplitude in mag., mutual events ΔM: 0.05 [D25d] pole direction Β, λ: ? , ? other data, secondary: diameter ds: >1.35 km [*D] diameter ratio ds/dp: >0.22 [D25d] component mag. difference ΔM: <3.3 rotation period RPs: ?