Asteroids

137126 1999CF9 help

Last update: 2025-09-23 13:32 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.707

Aphelion (Q)

2.834

Eccentricity (e)

0.601

Inclination (i)

5.5

deg

Orbit period (P)

860.2

Earth MOID

0.01770

U parameter

0.0

Next Earth close approach

Date

2046-08-23

Nominal distance (from Earth center)

0.05655

8459832

Maximum Brightness

14.7

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

mag

Diameter

900

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

61000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.770062

1-sigma variation

5.860E-10

Unit

Eccentricity (e)

Value

0.600830

1-sigma variation

1.365E-9

Unit

Inclination (i)

Value

5.5440

1-sigma variation

4.296E-6

Unit

Long. of Ascending Node (Ω)

Value

156.8454

1-sigma variation

9.924E-6

Unit

Arg. of Perihelion (ω)

Value

90.6127

1-sigma variation

9.807E-6

Unit

Mean Anomaly (M)

Value

88.13582

1-sigma variation

2.370E-7

Unit

Perihelion distance

Value

0.706555

1-sigma variation

Unit

Aphelion distance

Value

2.833568

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.147637

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.113310

1-sigma variation

Unit

MOID

Value

0.017698

1-sigma variation

Unit

Orbit Period

Value

860.1635

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	3.43406E-19	-3.85070E-19	2.42385E-15	1.07644E-15	-1.09598E-15	-1.22088E-16
e	-3.85070E-19	1.86203E-18	-2.18511E-15	-5.90992E-15	5.89856E-15	1.55794E-16
i	2.42385E-15	-2.18511E-15	1.84581E-11	1.53056E-11	-1.53050E-11	-8.11531E-13
Ω	1.07644E-15	-5.90992E-15	1.53056E-11	9.84905E-11	-9.72869E-11	-2.22606E-14
ω	-1.09598E-15	5.89856E-15	-1.53050E-11	-9.72869E-11	9.61727E-11	8.42429E-15
M	-1.22088E-16	1.55794E-16	-8.11531E-13	-2.22606E-14	8.42429E-15	5.61624E-14

Date of computation: 2025-09-23 13:32 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]

[2]

Taxonomy (all)

Value

Unit

Source

[3]

[2]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

18.039

Unit

mag

Source

[4]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[4]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

medium high

Unit

Source

[5]

Diameter

Value

900

Unit

Source

[5]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Radar R

Visual S

Unit

Source

[6]

[7]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Alexey V. Sergeyev and Benoit Carry A&A, 652 (2021) A59
[2]	EARN	1.) Bus, S.J. & Binzel, R.P. (2002) Icarus 158,106-145. (Phase II of the Small Main-Belt Asteroid Spectrographic Survey: A Feature-Based Taxonomy.)
[3]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[4]	ESA Aegis	ESA orbit determination and impact monitoring system
[5]	EARN	1.) Binzel, R.P. et al. (2002) in "Asteroids III" (Eds. W.F.Bottke et al.), Univ.Ariz.Press, Tucson, USA, pp. 255-271. (Physical Properties of NEOs)
[6]	EARN	1.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage
[7]	EARN	1.) Binzel, R.P. et al. (2001) Icarus 151,139-149. (Spectral Properties of Near-Earth Objects: Palomar and IRTF Results for 48 Objects Including Spacecraft Targets (9969) Braille and (10302) 1989 ML) 2.) Lim, L.F. et al. (2014) LPSC 45, 1695. (Thermal Emission Photometry of Three Near-Earth Asteroids in L' and M')(163249,277475,137126)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

9747

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.477708

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1999-01-15.34782

Unit

Source

[2]

Last Observation

Value

2025-09-22.608291

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

1112 (3)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2013-08-21

Unit

Source

[3]

Last Observation

Value

2025-03-10

Unit

Source

[3]

Delay (Discarded)

Value

8 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

4 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

12 (0)

Unit

Source

[1]

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
[3]	JPL Radar Observations	Jet Propulsion Laboratory: https://ssd.jpl.nasa.gov/dat/radar_data_ast.txt

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

One line per time step

Time step:*

* - these fields are required

Close Approaches for 137126 1999CF9 from 1950 to 2125

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possible distance in au	Distance uncert. in au
EARTH	1954-08-16 10:50	< 1 s	0.0319340	0.0319339	0.0000000
EARTH	1966-03-01 23:26	< 1 s	0.1635457	0.1635457	0.0000000
MARS	1983-01-21 17:52	< 1 s	0.0446225	0.0446225	0.0000000
EARTH	1999-03-25 06:53	< 1 s	0.1482322	0.1482322	0.0000000
EARTH	2013-08-23 00:27	< 1 s	0.0633819	0.0633819	0.0000000
EARTH	2025-03-08 01:36	< 1 s	0.0528265	0.0528265	0.0000000
EARTH	2046-08-23 11:37	< 1 s	0.0565505	0.0565503	0.0000001
EARTH	2065-03-31 10:47	< 1 s	0.1914091	0.1914090	0.0000000
EARTH	2079-08-11 10:06	< 1 s	0.1187361	0.1187357	0.0000001
VENUS	2093-07-26 13:02	< 1 min	0.0397065	0.0397062	0.0000001
EARTH	2098-03-08 10:01	< 1 min	0.0507431	0.0507420	0.0000004

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
44.82757509	226.01850125	0.01769848	MINIMUM
316.54353588	67.98879781	0.02265647	MINIMUM
0.95074486	147.29942534	0.31939721	SADDLE
0.97883231	327.37976046	1.69096198	SADDLE
180.24732994	326.47527518	1.85421824	SADDLE
180.26398496	146.48916085	3.84529045	MAXIMUM

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MOID Plots

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