Asteroids with Satellites Database--Johnston's Archive

(7930) 1987 VD

compiled by Wm. Robert Johnston
last updated 15 September 2024

--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: 2.2550664464 AU
orbital period P: 3.3864698769 yr
(= 1236.90812253 d)
eccentricity e: 0.25271710989
perihelion distance q: 1.6851725715 AU
aphelion distance Q: 2.8249603213 AU
inclination i: 5.139013067°
argument of perihelion ω: 67.33165001°
ascending node Ω: 277.68116555°
mean anomaly M: 5.88633266°
perihelion passage TP: 2024 Sep 26.7754092
Epoch: 2024 Oct 17
data arc: 1953-2024 (4238 obs.)
Earth MOID: 0.68551 AU
Jupiter Tisserand invariant TJ: 3.576

orbital data, secondary:
semimajor axis as: 4.7 km [*E]
separation/primary radius as/rp:3.2 [*E]
separation/Hill radius as/rH:0.012 [*E]
orbital period Ps: 0.609 ± 0.0002 d [B24n]
eccentricity es: ?
normalized ang. mom. αL: ?

other data, system (combined):
absolute mag. H: 14.85 [MPC]
slope parameter G: (0.15) [*A]
effective diameter dE: 3.05 ± 0.11 km [M19a]
geometric albedo: 0.628 ± 0.209 [M19a]
color index U-B: ?
color index B-V: ?
taxonomic type: ?
mass m: ?
density ρ: (1.6 g/cm3) [*A]
Hill radius rH: 390 km [*E]

other data, primary:
diameter dp: 2.95 ± 0.11 km [*D]
rotation period RPp: 2.5746 ± 0.0002 h [B24n]
amplitude in mag., rotational ΔM: 0.1 [B24n]
amplitude in mag., mutual events ΔM:0.07 [B24n]
pole direction Β, λ: ? , ?

other data, secondary:
diameter ds: >0.77 km [*D]
diameter ratio ds/dp: >0.26 [B24n]
component mag. difference ΔM: <2.93 [*D]
rotation period RPs: ?

-- (7930) 1987 VD --discovery and notes:

Primary discovered 1987 Nov 15 from Kushiro, Hokkaido, Japan by S. Ueda and H. Kaneda. Alternate designation(s): 1970 TC, 1994 YH, 1999 CU76. Linked to prediscovery observations from 1953 Jul 12. Permanent number assigned 1997 Oct 16.

Companion discovered 2024 Jul 17 by V. Benishek, P. Pravec, P. Kusnirak, P. Fatka, K. Ergashev, O. Burkhonov, Sh. Ehgamberdiev, A. Leroy, R. Durkee, and N. Ruocco using lightcurve observations from Sopot Observatory, Serbia; Maidanak Observatory, Uzbekistan; Observatoire de Besely, Ecole du Monde, Mahajanga, Madagascar; Shed of Science South Observatory, Pontotoc, Texas, USA; Osservatorio Astronomico Nastro Verde, Sorrento, Italy. Announced 2024 Sep 15 [B24n].

Possible third component suggested by additional rotation period [B24n].

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© 2024 by Wm. Robert Johnston.
Last modified 15 September 2024.
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