(2491)
_dynamical type, primary:_main belt asteroid, Hungaria
_orbital data, primary (osculating elements)_[JPL] :
| semimajor axis a: | 1.8776230116 AU |
|---|---|
| orbital period P: | 2.5728389319 yr (= 939.7471681 d) |
| eccentricity e: | 0.054172476 |
| perihelion distance q: | 1.775907524 AU |
| aphelion distance Q: | 1.9793384988 AU |
| inclination i: | 22.866198° |
| argument of perihelion ω: | 357.912752° |
| ascending node Ω: | 125.309799° |
| mean anomaly M: | 30.552926° |
| perihelion passage TP: | 2018 Jan 02.24437 |
| Epoch**:** | 2018 Mar 23 |
| data arc**:** | 1977-2018 (1394 obs.) |
| Earth MOID**:** | 0.790968 AU |
| Jupiter Tisserand invariant TJ: | 3.877 |
orbital data, secondary:
| semimajor axis as: | 7.5 km [*E] |
|---|---|
| separation/primary radius as/rp: | 4.7 [*D] |
| separation/Hill radius as/rH: | 0.016 [*D] |
| orbital period Ps: | 1.113 ± 0.0002 d [W18b] |
| eccentricity es: | ? |
| normalized ang. mom. αL: | ? |
other data, system (combined):
| absolute mag. H: | 13.68 [MPC] |
|---|---|
| slope parameter G: | (0.15) [*A] |
| effective diameter dE: | 3.26 ± 0.08 km [M11b] |
| geometric albedo**:** | 0.561 ± 0.207 [M11b] |
| color index U-B: | 0.261 [JPL] |
| color index B-V: | 0.756 [JPL] |
| taxonomic type**:** | X (Tholen) [JPL] |
| mass m: | ? |
| density ρ: | (1.6 g/cm3) [*A] |
| Hill radius rH: | 460 km [*E] |
other data, primary:
| diameter dp: | 3.17 km [*D] |
|---|---|
| rotation period RPp: | 4.0852 ± 0.0002 h [W18b] |
| amplitude in mag., rotational ΔM: | 0.08 ± 0.01 [W18b] |
| amplitude in mag., mutual events ΔM: | 0.085 ±0.03 [W18b] |
| pole direction Β, λ: | ? , ? |
other data, secondary:
| diameter ds: | >0.76 km [*D] |
|---|---|
| diameter ratio ds/dp: | >0.24 ± 0.02 [W18a] |
| component mag. difference ΔM: | >3.1 [*D] |
| rotation period RPs: | ? |