Asteroids

523972 1999CW8 help

Last update: 2026-07-30 09:40 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.899

Aphelion (Q)

3.575

Eccentricity (e)

0.598

Inclination (i)

33.6

deg

Orbit period (P)

1222.5

Earth MOID

0.23605

U parameter

0.0

Next Earth close approach

Date

Nominal distance (from Earth center)

Maximum Brightness

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

18.6

mag

Diameter

2100

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

1999-02-12

Observatory

Lincoln Laboratory ETS, New Mexico

ORBIT VISUALISATION TOOLS

External links

Proper elements

Epoch

Near present day

Near middle of observation arc

Orbit properties

Epoch
Semimajor Axis
Eccentricity (e)
Inclination (i)
Long. of Ascending Node (Ω)
Arg. of Perihelion (ω)
Mean Anomaly (M)
Perihelion distance
Aphelion distance
Asc. Node-Earth Sep.
Desc. Node-Earth Sep.
MOID
Orbit Period
U parameter

Value

1-sigma variation

Unit

Epoch

Value

61200.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

2.237479

1-sigma variation

5.544E-9

Unit

Eccentricity (e)

Value

0.597994

1-sigma variation

4.611E-8

Unit

Inclination (i)

Value

33.6312

1-sigma variation

2.314E-5

Unit

Long. of Ascending Node (Ω)

Value

316.7842

1-sigma variation

1.021E-5

Unit

Arg. of Perihelion (ω)

Value

262.2470

1-sigma variation

2.347E-5

Unit

Mean Anomaly (M)

Value

40.05535

1-sigma variation

0.00002

Unit

Perihelion distance

Value

0.899480

1-sigma variation

Unit

Aphelion distance

Value

3.575478

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.549333

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.344039

1-sigma variation

Unit

MOID

Value

0.236047

1-sigma variation

Unit

Orbit Period

Value

1222.4661

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	3.07390E-17	1.80255E-16	-6.04532E-15	9.91187E-15	6.61610E-14	-6.98507E-14
e	1.80255E-16	2.12592E-15	1.89891E-13	1.36781E-14	6.66296E-13	-5.14046E-13
i	-6.04532E-15	1.89891E-13	5.35623E-10	-1.16318E-10	2.22921E-10	-8.70614E-11
Ω	9.91187E-15	1.36781E-14	-1.16318E-10	1.04296E-10	-1.01266E-10	4.69171E-12
ω	6.61610E-14	6.66296E-13	2.22921E-10	-1.01266E-10	5.50904E-10	-3.12906E-10
M	-6.98507E-14	-5.14046E-13	-8.70614E-11	4.69171E-12	-3.12906E-10	2.38362E-10

Date of computation: 2026-07-30 09:40 UTC

Note: The ASCII file is in a format suitable for Orbfit input.

Download ASCII file:

Physical properties

Rotation Period
Quality
Amplitude
Rotation Direction
Spinvector L
Spinvector B

Rotational properties

Value

Unit

Source

Rotation Period

Value

Unit

Source

[-]

Quality

Value

Unit

Source

[-]

Amplitude

Value

Unit

mag

Source

[-]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

Unit

Source

[-]

Spinvector B

Value

Unit

Source

[-]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[1]

Taxonomy (all)

Value

Unit

Source

[1]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

18.63

Unit

mag

Source

[2]

Slope Parameter (G)

Value

0.15**

Unit

Source

[2]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.015

Unit

Source

[3]

Diameter

Value

2100

Unit

Source

[3]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Visual S

Unit

Source

[1]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Binzel, R.P. et al. (2004) Icarus 170, 259-294. (Observed spectral properties of near-Earth objects: results for population distribution, source regions, and space weathering processes.)
[2]	ESA Aegis	ESA orbit determination and impact monitoring system
[3]	EARN	1.) Joseph R. Masiero et al 2021 Planet. Sci. J. 2 162

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

7506

Unit

Source

[1]

Unobserved

Value

2530

Unit

Source

[1]

Normalized RMS of residuals

Value

0.567619

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1999-02-12.19423

Unit

Source

[2]

Last Observation

Value

2019-09-01.24387

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

217 (2)

Unit

Source

[1]

Radar Summary

First Observation
Last Observation
Delay (Discarded)
Doppler (Discarded)
Total Optical Observations (Discarded)

Radar

Value

Unit

Source

First Observation

Value

Unit

Source

[-]

Last Observation

Value

Unit

Source

[-]

Delay (Discarded)

Value

0 (0)

Unit

Source

[-]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[-]

Note: The ASCII file is in a format suitable for Orbfit input.

Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	MPC	Minor Planet Center: https://www.minorplanetcenter.net

Filters

Initial Date: *

Final Date: *

Normalised Only accepted

Max residual (arcsec):

* - these fields are required

Plot

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

One line per time step

Time step:*

* - these fields are required

Note: Ephemerides requests are limited to a maximum of 1000 points and a final date not exceeding 2040/12/31 00:00.

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
323.76491881	45.22712035	0.23604718	MINIMUM
41.23450275	192.20361485	0.33246527	MINIMUM
4.55919588	122.89579435	0.56245692	SADDLE
2.37052498	297.62689413	1.81231460	SADDLE
181.51438666	294.29034965	2.79912347	SADDLE
179.47020262	113.07429142	4.45142933	MAXIMUM

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MOID Plots

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