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Summary for : 2P/Encke

Dyn	T.T	T.B	T T.L B	T.D	Density (g/cm^3)	Δρ/ρ	Diameter (km)	ΔD/D	Mass (kg)	ΔM/M	Ref	Avg.M
COM	-	-	- \| -	-	1.71 ± 1.39 (D)	82 %	4.7 ± 0.8	17.2 %	9.20e+13 ± 5.80e+13	63 %	S	EVM
COM	-	-	- \| -	-	2.01 ± 1.98 (D)	98 %	4.4 ± 1.1	25.2 %	9.20e+13 ± 5.80e+13	63 %	S	w.avg
COM	-				1.67 ± 1.36 (D)	81 %	4.7 ± 0.8	17.2 %	9.20e+13 ± 5.80e+13	63 %	C	?

Average asteroid densities (g/cm^3):
C = 1.3 ± 0.6, B = 2.4 ± 0.5, S = 2.7 ± 0.5, M = 3.5 ± 1.0, P = 2.8 ± 1.6, X = 1.9 ± 0.8, Xc = 4.9 ± 0.9, Xk = 4.2 ± 0.7 (Ref)

Additional resources:

Note: The density estimates have been ranked from (A) to (E), corresponding to the relative error: (B) less than 20%, (C) between 20 and 50%, (D) between 50 and 100%, and (E) more than 100%. (A) stands for (presumably) reliable estimates (accuracy better than 20%), based on more than 5 mass estimates and 5 diameter estimates, or a spacecraft encounter. Apparently unrealistic densities (ρ > 8) are tagged with (X).

EVM: average by using the Expected Value Method (Ref). w.avg: weighted average (with w = 1/err^2).

T.T: Tholen Tax Class. T.B: Bus & Binzel Tax Class. T T.L: S3OS2 Lazarro (Tholen) Tax Class. T.L B: S3OS2 Lazarro (Bus & Binzel) Tax Class. T.D: DeMeo Tax Class.

Ref: S = SiMDA, C = Carry (2012)

Diameter estimates

Designation	Diameter / Err (km)	ΔD/D	Method	Year	Ref	N	χ²	Use
2P/Encke	6.00 ± 2.00	33.3 %	H-mag	2009	D56		0.43	1
2P/Encke	4.19 ± 0.80	19.1 %	H-mag	2009	D56		0.38	2

plot, average diameter and derived density

All

Notes (N):
1: This estimate is discarded for the average diameter (and derived density) calculation in Carry (2012).
2: This estimate is discarded for the average diameter (and derived density) calculation in SiMDA (catalog).

H-mag : Crude estimate from absolute magnitude.

EVM diam. average D = (4.7 ± 0.81) km (ΔD/D = 17%, SNR = 5.81) Derived bulk density ρ = (1.71 ± 1.39) g/cm³ (Δρ/ρ = 82%, SNR = 1.2)

References

D56

(2009):

Sosa, A., Fernández, J.A., 2009. Cometary masses derived from nongravitational forces. Monthly Notices of the Royal Astronomical Society 393, 192–214.

Mass estimates

Notes (N):
1: This estimate is discarded for the average mass (and derived density) calculation in Carry (2012).
2: This estimate is discarded for the average mass (and derived density) calculation in SiMDA (catalog).
3: This estimate is an average of individual solutions listed before under the same reference (e.g. M125).

CNGF : Non-gravitational forces (comets).

EVM mass average M = (9.200 ± 5.800) × 10¹³ kg (ΔM/M = 63%, SNR = 1.6) Derived bulk density ρ = (1.71 ± 1.39) g/cm³ (Δρ/ρ = 82%, SNR = 1.2)