Asteroids with Satellites Database--Johnston's Archive

(199145) 2005 YY128

compiled by Wm. Robert Johnston
last updated 15 April 2023

--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, Apollo (PHA)


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 1.6494042506 AU
orbital period P: 2.1183556059 yr
(= 773.7293851 d)
eccentricity e: 0.731381246
perihelion distance q: 0.443060915 AU
aphelion distance Q: 2.8557475858 AU
inclination i: 3.7573881°
argument of perihelion ω: 314.875295°
ascending node Ω: 300.22136°
mean anomaly M: 342.47151053°
perihelion passage TP: 2023 Apr 03.6730761
Epoch: 2023 Feb 25
data arc: 2005-2023 (493 obs.)
Earth MOID: 0.0294205 AU
Jupiter Tisserand invariant TJ: 3.921


orbital data, secondary:
semimajor axis as: ?
orbital period Ps: ?
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 18.32 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 0.53 km [*E]
geometric albedo: 0.3 [*D]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 17 km [*E]

other data, primary:
diameter dp: 0.45 km [*E]
rotation period RPp: ?
amplitude in mag., rotational ΔM: ?
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 0.3 km [*E]
diameter ratio ds/dp: 0.67 [*D]
component mag. difference ΔM: 0.9 [*D]
rotation period RPs: ?

-- (199145) 2005 YY128 --discovery and notes:

Primary discovered 2005 Dec 30 from Kitt Peak Observatory, Arizona, USA by Spacewatch Program. Alternate designation(s): 1970 BD. Linked to prediscovery observations from 1970 Jan. Permanent number assigned 2008 Nov 13.

Companion discovered 2023 Feb using radar observations from Goldstone Observatory, California, USA. Announced 2023 Feb [B23e].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2023 by Wm. Robert Johnston.
Last modified 15 April 2023
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