Asteroids

425755 2011CP4 help

Last update: 2025-09-10 00:30 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Aten

Perihelion (q)

0.118

Aphelion (Q)

1.705

Eccentricity (e)

0.870

Inclination (i)

9.5

deg

Orbit period (P)

318.0

Earth MOID

0.01912

U parameter

1.1

A₂

53.5

10^-15au/days²

Next Earth close approach

Date

2028-01-07

Nominal distance (from Earth center)

0.1919

28708304

Maximum Brightness

21.3

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

21.1

mag

Diameter

160 - 400*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2011-02-02

Observatory

Pan-STARRS 1, Haleakala

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

0.911723

1-sigma variation

1.099E-8

Unit

Eccentricity (e)

Value

0.870330

1-sigma variation

1.966E-8

Unit

Inclination (i)

Value

9.4699

1-sigma variation

8.027E-6

Unit

Long. of Ascending Node (Ω)

Value

147.9672

1-sigma variation

7.731E-6

Unit

Arg. of Perihelion (ω)

Value

159.9389

1-sigma variation

8.595E-6

Unit

Mean Anomaly (M)

Value

239.26003

1-sigma variation

0.00004

Unit

Perihelion distance

Value

0.118223

1-sigma variation

Unit

Aphelion distance

Value

1.705222

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.223212

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.890921

1-sigma variation

Unit

MOID

Value

0.019121

1-sigma variation

Unit

Orbit Period

Value

317.9747

1-sigma variation

Unit

U parameter

Value

1.1

1-sigma variation

Unit

A₂

Value

53.46211

1-sigma variation

6.63522

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	1.20800E-16	5.99777E-18	1.43529E-15	5.89245E-15	-3.89834E-15	-3.28324E-13	7.29049E-8
e	5.99777E-18	3.86497E-16	-1.38609E-15	-9.41116E-14	1.24881E-13	-1.83294E-13	6.35762E-9
i	1.43529E-15	-1.38609E-15	6.44391E-11	2.77987E-11	-2.87788E-11	3.45544E-11	5.67284E-7
Ω	5.89245E-15	-9.41116E-14	2.77987E-11	5.97641E-11	-6.54937E-11	5.11845E-11	2.47580E-6
ω	-3.89834E-15	1.24881E-13	-2.87788E-11	-6.54937E-11	7.38771E-11	-7.09590E-11	-1.07243E-6
M	-3.28324E-13	-1.83294E-13	3.45544E-11	5.11845E-11	-7.09590E-11	1.84421E-9	-2.01130E-4
A₂	7.29049E-8	6.35762E-9	5.67284E-7	2.47580E-6	-1.07243E-6	-2.01130E-4	4.40262E1

Date of computation: 2025-09-10 00:30 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

[-]

Taxonomy (all)

Value

Unit

Source

[-]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

21.132

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

160 - 400*

Unit

Source

[2]

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

Unit

Source

[3]

Download this part as:

Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	Estimation	Estimated from absolute magnitude
[3]	EARN	1.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

8449

Unit

Source

[1]

Unobserved

Value

240

Unit

Source

[1]

Normalized RMS of residuals

Value

0.701963

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2002-01-10.23562

Unit

Source

[2]

Last Observation

Value

2025-02-27.183821

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

182 (6)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2012-02-21

Unit

Source

[3]

Last Observation

Value

2012-02-27

Unit

Source

[3]

Delay (Discarded)

Value

4 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

7 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

11 (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 425755 2011CP4 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
MERCURY	1951-04-17 17:43	5.6	0.0296366	0.0292357	0.0001337
EARTH	1958-02-26 17:08	1.8	0.1526304	0.1523682	0.0000874
EARTH	1961-01-02 11:11	4.5	0.1234141	0.1233303	0.0000280
MERCURY	1962-08-12 00:46	6.5	0.0208895	0.0204424	0.0001493
EARTH	1965-02-22 00:18	4.5	0.0343428	0.0341012	0.0000806
EARTH	1967-12-29 16:33	1.6	0.1915279	0.1913319	0.0000654
MERCURY	1973-12-05 17:22	4.3	0.0144174	0.0141543	0.0000881
EARTH	1981-01-06 19:06	1.6	0.1901529	0.1900898	0.0000210
EARTH	1985-02-25 04:33	< 1 min	0.0791027	0.0790900	0.0000042
VENUS	1985-03-16 19:16	< 1 min	0.0082953	0.0082948	0.0000002
MERCURY	1985-03-31 09:04	< 1 min	0.0451323	0.0451099	0.0000075
EARTH	1988-01-01 00:21	< 1 min	0.1263508	0.1263469	0.0000013
EARTH	1992-02-20 00:16	< 1 min	0.1128066	0.1127980	0.0000028
EARTH	2005-02-27 02:59	< 1 s	0.1803145	0.1803127	0.0000006
EARTH	2008-01-04 08:29	< 1 min	0.1327227	0.1327221	0.0000002
EARTH	2012-02-23 14:01	< 1 s	0.0234038	0.0234038	0.0000000
MERCURY	2012-03-24 02:16	< 1 s	0.0344542	0.0344541	0.0000000
EARTH	2014-12-29 22:04	< 1 s	0.1838963	0.1838959	0.0000001
VENUS	2020-11-21 03:31	< 1 min	0.0228966	0.0228952	0.0000005
MERCURY	2023-07-17 21:15	< 1 min	0.0315663	0.0315642	0.0000007
EARTH	2028-01-07 22:44	< 1 min	0.1919032	0.1919015	0.0000006
EARTH	2032-02-26 07:01	< 1 min	0.0808907	0.0808870	0.0000012
EARTH	2035-01-01 02:44	< 1 min	0.1262240	0.1262223	0.0000006
EARTH	2039-02-20 00:24	< 1 min	0.1145737	0.1145666	0.0000024
EARTH	2052-02-28 03:41	< 1 min	0.1786946	0.1786793	0.0000051
EARTH	2055-01-04 09:19	< 1 min	0.1322529	0.1322448	0.0000027
EARTH	2059-02-23 17:35	< 1 min	0.0229418	0.0229315	0.0000034
MERCURY	2061-11-03 06:27	< 1 min	0.0185492	0.0185104	0.0000129
EARTH	2061-12-30 01:43	< 1 min	0.1796124	0.1795925	0.0000066
VENUS	2067-01-10 06:02	< 1 min	0.0246170	0.0245725	0.0000148
EARTH	2075-01-07 12:19	< 1 min	0.1811709	0.1811544	0.0000055
EARTH	2079-02-25 15:53	< 1 min	0.0547850	0.0547721	0.0000043
EARTH	2081-12-31 08:33	< 1 min	0.1414807	0.1414760	0.0000016
EARTH	2086-02-18 08:51	< 1 s	0.1578091	0.1578086	0.0000002
MERCURY	2088-10-24 04:27	< 1 min	0.0124914	0.0124871	0.0000014
VENUS	2092-04-02 13:22	< 1 min	0.0259353	0.0259225	0.0000043
EARTH	2099-02-27 11:57	< 1 min	0.1286192	0.1286053	0.0000046
EARTH	2102-01-03 18:13	< 1 min	0.1188926	0.1188916	0.0000003
EARTH	2106-02-22 22:06	< 1 min	0.0701740	0.0701592	0.0000049
MERCURY	2115-10-17 19:24	< 1 min	0.0328215	0.0328046	0.0000056
EARTH	2122-01-06 16:33	< 1 min	0.1476187	0.1476159	0.0000009

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
264.23431579	51.62936681	0.01916292	MINIMUM
95.23359926	359.04925251	0.11868030	MINIMUM
179.48173754	25.55005957	0.72363364	SADDLE
357.95861360	201.14556022	0.89696676	SADDLE
358.07269387	21.53742872	1.10303144	SADDLE
179.97053677	205.66941373	2.71878837	MAXIMUM

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MOID Plots

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