Asteroids

5381 Sekhmet help

Last update: 2025-08-15 12:45 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Aten

Perihelion (q)

0.667

Aphelion (Q)

1.228

Eccentricity (e)

0.296

Inclination (i)

49.0

deg

Orbit period (P)

336.8

Earth MOID

0.11098

U parameter

0.0

Next Earth close approach

Date

2038-05-20

Nominal distance (from Earth center)

0.19857

29706025

Maximum Brightness

15.6

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

16.7

mag

Diameter

1410

Taxonomic type

Rotation period (T)

2.823

Discovery Information

Discovery Date

1991-05-14

Observatory

Palomar Mountain

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

0.947433

1-sigma variation

1.028E-9

Unit

Eccentricity (e)

Value

0.296430

1-sigma variation

2.147E-7

Unit

Inclination (i)

Value

48.9662

1-sigma variation

1.961E-5

Unit

Long. of Ascending Node (Ω)

Value

58.5292

1-sigma variation

4.460E-6

Unit

Arg. of Perihelion (ω)

Value

37.4310

1-sigma variation

1.904E-5

Unit

Mean Anomaly (M)

Value

266.61831

1-sigma variation

0.00004

Unit

Perihelion distance

Value

0.666586

1-sigma variation

Unit

Aphelion distance

Value

1.228281

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.288486

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.116792

1-sigma variation

Unit

MOID

Value

0.110979

1-sigma variation

Unit

Orbit Period

Value

336.8383

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.05613E-18	-4.67499E-17	-1.35724E-15	7.90249E-16	-1.10613E-14	7.70080E-15
e	-4.67499E-17	4.61101E-14	2.98771E-13	-2.85135E-13	2.34216E-12	-7.39576E-12
i	-1.35724E-15	2.98771E-13	3.84494E-10	-6.73000E-11	7.52061E-11	-5.65520E-11
Ω	7.90249E-16	-2.85135E-13	-6.73000E-11	1.98959E-11	-1.02120E-11	9.52462E-12
ω	-1.10613E-14	2.34216E-12	7.52061E-11	-1.02120E-11	3.62442E-10	-5.83940E-10
M	7.70080E-15	-7.39576E-12	-5.65520E-11	9.52462E-12	-5.83940E-10	1.49743E-9

Date of computation: 2025-08-15 12:45 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

2.823

Unit

Source

[4]

Quality

Value

3,B,R

Unit

Source

[4]

Amplitude

Value

0.1

Unit

mag

Source

[4]

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

16.717

Unit

mag

Source

[5]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[5]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.3243

Unit

Source

[7]

Diameter

Value

1410

Unit

Source

[6]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.5453

Unit

g-r

Source

[1]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Visual S

Radar R

Unit

Source

[2]

[8]

Satellites

Satellites

Value

Unit

Source

Satellites

Value

Binary Child 1

Unit

Source

[3]

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Sources

No.	Name	Additional
[1]	EARN	1.) A. V. Sergeyev, B. Carry et al A&A, 658 (2022) A109
[2]	EARN	1.) Davies, J.K. et al. (2007) Icarus 186,111-125. (Near-infrared spectra of 12 near-Earth objects) (1627,4179, 5381,5587,6489,11405,14402,25143,25330,52760,66391,101955)
[3]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[4]	EARN	1.) Warner, B.D. & A.W. Harris (JPL) (2014) MPB 41, 224-226. (LIGHTCURVE ANALYSIS OF THE NEA BINARY ASTEROID 5381 SEKHMET) 2.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods" 3.) Nolan, M.C. et al. (2003) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/08100/08163.html"> 8163. (5381 Sekhmet) (radar observation, binary asteroid)
[5]	ESA Aegis	ESA orbit determination and impact monitoring system
[6]	EARN	1.) Delbo, M. et al. (2011) Icarus 212, 138-148. (The cool surfaces of binary near-Earth asteroids) (5381,153591, 164121) 2.) Nugent, C.R. et al. (2015) Astrophys. J. 814_117 (13pp) (NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos)(201 NEOs) 3.) Masiero, J.R. et al. (2018) Astron. J. 154_168(10pp). (NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos) (170NEOs, 6110MBAs)
[7]	EARN	1.) Masiero, J.R. et al. (2018) Astron. J. 154_168(10pp). (NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos) (170NEOs, 6110MBAs) 2.) Delbo, M. et al. (2011) Icarus 212, 138-148. (The cool surfaces of binary near-Earth asteroids) (5381,153591, 164121) 3.) Nugent, C.R. et al. (2015) Astrophys. J. 814_117 (13pp) (NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos)(201 NEOs)
[8]	EARN	1.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage 2.) Nolan, M.C. et al. (2003) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/08100/08163.html"> 8163. (5381 Sekhmet) (radar observation, binary asteroid)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

12493

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.545523

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1991-05-14.43646

Unit

Source

[2]

Last Observation

Value

2025-07-27.802741

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

686 (7)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2015-05-03

Unit

Source

[3]

Last Observation

Value

2015-05-03

Unit

Source

[3]

Delay (Discarded)

Value

1 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

1 (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 5381 Sekhmet 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	1955-05-20 10:28	< 1 s	0.1850975	0.1850966	0.0000003
EARTH	1967-05-19 12:53	< 1 s	0.1464065	0.1464058	0.0000002
EARTH	1979-05-18 18:56	< 1 s	0.1196600	0.1196598	0.0000001
EARTH	1991-05-18 04:10	< 1 s	0.1127972	0.1127969	0.0000001
EARTH	2003-05-17 16:44	< 1 s	0.1284936	0.1284933	0.0000001
EARTH	2015-05-17 08:33	< 1 s	0.1613288	0.1613286	0.0000001
EARTH	2038-05-20 20:39	< 1 s	0.1985725	0.1985718	0.0000002
EARTH	2050-05-19 23:13	< 1 s	0.1598799	0.1598791	0.0000003
EARTH	2062-05-19 07:34	< 1 s	0.1333617	0.1333609	0.0000003
EARTH	2074-05-18 20:57	< 1 s	0.1187719	0.1187714	0.0000002
EARTH	2086-05-18 13:29	< 1 s	0.1135196	0.1135193	0.0000001
EARTH	2098-05-18 09:11	< 1 s	0.1136194	0.1136192	0.0000001
EARTH	2110-05-19 06:35	< 1 min	0.1156777	0.1156772	0.0000002
EARTH	2122-05-19 05:16	< 1 min	0.1182554	0.1182547	0.0000002

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
127.47596178	134.93750149	0.11097864	MINIMUM
328.63971110	315.38429627	0.28487663	MINIMUM
41.69716899	48.90337220	0.75107518	SADDLE
238.54506346	216.41697535	0.86710324	SADDLE
29.53528853	206.62877804	1.58014934	SADDLE
160.61902244	332.47445422	2.17333407	MAXIMUM

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MOID Plots

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