Asteroids with Satellites Database--Johnston's Archive

2021 DN15

compiled by Wm. Robert Johnston
last updated 24 December 2021

--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: TNO


orbital data, primary (osculating elements) [JPL] :
semimajor axis a: 43.74 AU
orbital period P: 289.3 yr
(= 105666 d)
eccentricity e: 0.04
perihelion distance q: 42 AU
aphelion distance Q: 45.5 AU
inclination i: 2.847°
argument of perihelion ω: 292°
ascending node Ω: 133.064°
mean anomaly M: 53°
perihelion passage TP: 1978 Jun 21
Epoch: 2021 Apr 07
data arc: 2021 Feb-Dec (9 obs.)
Earth MOID: 40.998 AU
Jupiter Tisserand invariant TJ: 5.906
Neptune Tisserand invariant TN:3.095 [*D]


orbital data, secondary:
semimajor axis as: 31900 km (separation) [S21d]
separation/primary radius as/rp:500 [*E]
separation/Hill radius as/rH:0.070 [*E]
orbital period Ps: 1100 d [*E]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H:
6.98 ± 0.08 [JPL]
slope parameter G: (0.15) [*A]
effective diameter dE: 177 km [*E]
geometric albedo: (0.09 ) [*A]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1 g/cm3) [*A]
Hill radius rH: 460000 km [*E]

other data, primary:
diameter dp: 128 km [*E]
rotation period RPp: ?
amplitude in mag., rotational ΔM: ?
pole direction Β, λ: ? , ?


other data, secondary:
diameter ds: 122 km [*E]
diameter ratio ds/dp: 0.95 [*D]
component mag. difference ΔM: 0.1 [S21d]
rotation period RPs: ?

-- 2021 DN15 --discovery and notes:

Primary discovered 2021 Feb 17 from Subaru Telescope, Mauna Kea Observatory, Hawaii, USA by ?.

Companion discovered 2021 Feb 17 by S. S. Sheppard, D. J. Tholen, and C. A. Trujillo using adaptive optics telescope observations from Subaru Telescope, Mauna Kea Observatory, Hawaii, USA. Announced 2021 Dec 19 [S21d].

--Links, more technical:

--Links, less technical:

--Links to ADS abstracts:


© 2021 by Wm. Robert Johnston.
Last modified 24 December 2021.
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