(539940) 2017 HW1

--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: 2.13745098 AU orbital period P: 3.124958435 yr (= 1141.412625 d) eccentricity e: 0.4588695 perihelion distance q: 1.15663991 AU aphelion distance Q: 3.11826205 AU inclination i: 33.944796° argument of perihelion ω: 168.892117° ascending node Ω: 41.3439928° mean anomaly M: 11.653678° perihelion passage TP: 2020 Apr 24.05096 Epoch: 2020 May 31 data arc: 2012-2020 (495 obs.) Earth MOID: 0.154952 AU Jupiter Tisserand invariant TJ: 3.379 orbital data, secondary: semimajor axis as: 20 km [*E] separation/primary radius as/rp: 45 [*E] separation/Hill radius as/rH: 0.25 [*E] orbital period Ps: 1.092 ± 0.004 d [W20a] eccentricity es: ? normalized ang. mom. αL: ?

other data, system (combined): absolute mag. H: 17.8 [MPC] slope parameter G: (0.15) [*A] effective diameter dE: 0.92 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: 80 km [*E] other data, primary: diameter dp: 0.88 km [*E] rotation period RPp: 2.633 ± 0.001 h [W20a] amplitude in mag., rotational ΔM: 0.12 [W20a] amplitude in mag., mutual events ΔM: 0.105 ±0.015 [W20a] pole direction Β, λ: ? , ? other data, secondary: diameter ds: >0.27 km [*E] diameter ratio ds/dp: >0.31 ± 0.03 [W20a] component mag. difference ΔM: <2.5 [*D] rotation period RPs: ?