Asteroids with Satellites Database--Johnston's Archive

(25015) Lairdclose

compiled by Wm. Robert Johnston
last updated 20 October 2019

--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: 2.2285435929 AU
orbital period P: 3.326838362 yr
(= 1215.1506614 d)
eccentricity e: 0.197904727
perihelion distance q: 1.787504282 AU
aphelion distance Q: 2.6695829043 AU
inclination i: 5.7557088°
argument of perihelion ω: 41.408169°
ascending node Ω: 265.724839°
mean anomaly M: 91.790797°
perihelion passage TP: 2018 Jun 21.167644
Epoch: 2019 Apr 27
data arc: 1968-2019 (1607 obs.)
Earth MOID: 0.776501 AU
Jupiter Tisserand invariant TJ: 3.611


orbital data, secondary:
semimajor axis as: 8.9 km [*E]
separation/primary radius as/rp:6.7 [*E]
separation/Hill radius as/rH:0.019 [*E]
orbital period Ps: 1.833 ± 0.0012 d [W19c]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 14.7 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 2.899 ± 0.353 km [M19a]
geometric albedo: 0.365 ± 0.134 [**]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 470 km [*E]

other data, primary:
diameter dp: 2.64 ± 0.35 km [*D]
rotation period RPp: 4.4011 ± 0.0003 h [B18o]
amplitude in mag., rotational ΔM: 0.27 [B18o]
amplitude in mag., mutual events ΔM:0.2 ±0.06 [B18o]
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 1.19 ± 0.18 km [*D]
diameter ratio ds/dp: 0.45 ± 0.04 [W19c]
component mag. difference ΔM: 1.7 ± 0.2 [*D]
rotation period RPs: ?

-- (25015) Lairdclose --discovery and notes:

Primary discovered 1998 Aug 19 from Haleakala, Hawaii, USA by JPL/GEODSS NEAT. Alternate designation(s): 1998 QN2, 1999 JL6. Linked to prediscovery observations from 1968 Jul 25. Permanent number assigned 2001 Jun 06.

Named 2019 Aug 27 for Eugene G. Fahnestock (1980-) [MPC115894].

Companion discovered 2018 Aug 13 by V. Benishek, P. Pravec, J. Oey, R. Groom, D. Pray, and V. Chiorny using lightcurve observations from Sopot Observatory, Serbia; Blue Mountains Observatory; Darling range Observatory; Sugarloaf Mountain Observatory; Chuguev Station, Kharkiv Observatory, Ukraine. Announced 2018 Sep 14 [B18o].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2018, 2019 by Wm. Robert Johnston.
Last modified 20 October 2019.
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