Asteroids

11885 Summanus help

Last update: 2026-06-04 23:11 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.895

Aphelion (Q)

2.511

Eccentricity (e)

0.475

Inclination (i)

19.4

deg

Orbit period (P)

811.8

Earth MOID

0.06708

U parameter

0.0

Next Earth close approach

Date

2031-03-20

Nominal distance (from Earth center)

0.14759

22078577

Maximum Brightness

16.9

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

18.5

mag

Diameter

1230

Taxonomic type

Rotation period (T)

7.368

Discovery Information

Discovery Date

1990-09-25

Observatory

Steward Observatory, Kitt Peak-Spacewatch

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

1.703132

1-sigma variation

2.507E-9

Unit

Eccentricity (e)

Value

0.474570

1-sigma variation

3.535E-8

Unit

Inclination (i)

Value

19.4329

1-sigma variation

1.038E-5

Unit

Long. of Ascending Node (Ω)

Value

359.7611

1-sigma variation

9.256E-6

Unit

Arg. of Perihelion (ω)

Value

116.2413

1-sigma variation

1.145E-5

Unit

Mean Anomaly (M)

Value

325.31939

1-sigma variation

0.00001

Unit

Perihelion distance

Value

0.894877

1-sigma variation

Unit

Aphelion distance

Value

2.511386

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.665948

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.094951

1-sigma variation

Unit

MOID

Value

0.067084

1-sigma variation

Unit

Orbit Period

Value

811.8406

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	6.28722E-18	-2.23377E-17	-3.77320E-15	-2.62482E-15	6.07015E-15	-1.38999E-14
e	-2.23377E-17	1.24962E-15	-3.25217E-14	6.52779E-14	6.00449E-14	-3.20059E-14
i	-3.77320E-15	-3.25217E-14	1.07829E-10	3.43390E-15	-7.14299E-12	1.34820E-11
Ω	-2.62482E-15	6.52779E-14	3.43390E-15	8.56814E-11	-6.99548E-11	-2.51138E-13
ω	6.07015E-15	6.00449E-14	-7.14299E-12	-6.99548E-11	1.31204E-10	-4.15365E-11
M	-1.38999E-14	-3.20059E-14	1.34820E-11	-2.51138E-13	-4.15365E-11	4.96226E-11

Date of computation: 2026-06-04 23:11 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

7.368

7.358

Unit

Source

[1]

[2]

Quality

Value

Unit

Source

[2]

Amplitude

Value

0.18

Unit

mag

Source

[2]

[1]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

157

Unit

Source

[1]

Spinvector B

Value

Unit

Source

[1]

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

18.529

Unit

mag

Source

[3]

Slope Parameter (G)

Value

0.15**

Unit

Source

[3]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.044

0.372

Unit

Source

[4]

[5]

Diameter

Value

1230

Unit

Source

[4]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Unit

Source

[-]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Lowell Observatory Near-Earth Asteroid Photometric Survey (NEAPS): Paper 3. Skiff, Brian A et al.
[2]	EARN	1.) Skiff, B.A. (2011) Posting on CALL web site. http://www.minorplanet.info/call.html
[3]	ESA Aegis	ESA orbit determination and impact monitoring system
[4]	EARN	1.) Joseph R. Masiero et al 2021 Planet. Sci. J. 2 162
[5]	EARN	1.) Mainzer, A.; Grav, T.; Masiero, J.; Bauer, J.; et al. (2012) Astrophys. J. Let. 760, L12.

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

12032

Unit

Source

[1]

Unobserved

Value

1034

Unit

Source

[1]

Normalized RMS of residuals

Value

0.518725

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1990-09-25.19848

Unit

Source

[2]

Last Observation

Value

2023-09-04.308176

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

398 (0)

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

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Final Date: *

Normalised Only accepted

Max residual (arcsec):

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Computation parameters

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Initial Date: *

Final Date: *

Output option:

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

Close Approaches for 11885 Summanus from 1950 to 2126

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possible distance in au	Distance uncert. in au
EARTH	1971-03-20 02:21	< 1 min	0.1447003	0.1446991	0.0000004
EARTH	1991-03-17 14:34	< 1 min	0.1023391	0.1023385	0.0000002
EARTH	2011-03-17 13:23	< 1 s	0.1020623	0.1020620	0.0000001
EARTH	2031-03-20 09:22	< 1 min	0.1475862	0.1475854	0.0000003
EARTH	2120-03-01 03:39	< 1 min	0.1996290	0.1996275	0.0000005

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
35.26402824	70.28980952	0.06636016	MINIMUM
316.85640308	306.71784959	0.29368631	MINIMUM
344.12355933	348.60737334	0.32737418	SADDLE
177.09344594	194.34440046	1.57121422	SADDLE
358.04440666	192.38553765	1.89018945	SADDLE
181.64425959	17.17410388	3.46375180	MAXIMUM

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MOID Plots

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