Asteroids

415029 2011UL21 help

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

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.735

Aphelion (Q)

3.510

Eccentricity (e)

0.654

Inclination (i)

34.9

deg

Orbit period (P)

1129.3

Earth MOID

0.01657

U parameter

0.0

Next Earth close approach

Date

2089-06-25

Nominal distance (from Earth center)

0.01782

2666325

Maximum Brightness

8.2

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

15.9

mag

Diameter

2310

Taxonomic type

Rotation period (T)

2.732

Discovery Information

Discovery Date

2011-10-17

Observatory

University of Arizona Catalina Sky Survey

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

2.122316

1-sigma variation

4.456E-9

Unit

Eccentricity (e)

Value

0.653834

1-sigma variation

1.087E-8

Unit

Inclination (i)

Value

34.8870

1-sigma variation

5.612E-6

Unit

Long. of Ascending Node (Ω)

Value

275.3104

1-sigma variation

1.070E-6

Unit

Arg. of Perihelion (ω)

Value

284.9799

1-sigma variation

2.833E-6

Unit

Mean Anomaly (M)

Value

241.51950

1-sigma variation

7.887E-7

Unit

Perihelion distance

Value

0.734673

1-sigma variation

Unit

Aphelion distance

Value

3.509958

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.022787

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.478336

1-sigma variation

Unit

MOID

Value

0.016572

1-sigma variation

Unit

Orbit Period

Value

1129.3106

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.98521E-17	3.48779E-17	1.82768E-15	-3.86285E-16	-7.38311E-15	-3.08145E-15
e	3.48779E-17	1.18186E-16	9.15592E-16	-2.01426E-15	-2.55639E-14	-4.85147E-15
i	1.82768E-15	9.15592E-16	3.14931E-11	1.41023E-12	-2.83617E-12	1.47859E-13
Ω	-3.86285E-16	-2.01426E-15	1.41023E-12	1.14385E-12	-9.48124E-13	1.12217E-13
ω	-7.38311E-15	-2.55639E-14	-2.83617E-12	-9.48124E-13	8.02703E-12	6.30475E-13
M	-3.08145E-15	-4.85147E-15	1.47859E-13	1.12217E-13	6.30475E-13	6.22100E-13

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

2.732

Unit

Source

[4]

Quality

Value

Unit

Source

[4]

Amplitude

Value

0.32

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]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

15.903

Unit

mag

Source

[5]

Slope Parameter (G)

Value

0.15**

Unit

Source

[5]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.158

Unit

Source

[6]

Diameter

Value

2310

Unit

Source

[6]

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.) Michaël Marsset et al 2022 AJ 163 165
[2]	EARN	1.) Alexey V. Sergeyev and Benoit Carry A&A, 652 (2021) A59
[3]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[4]	EARN	1.) Warner, B.D. (2018) MPB 45, 366-379. (Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2018 April-June)(39 NEAs) 2.) Warner, B.D. (2018) MPB 45, 138-147. (NEAR-EARTH ASTEROID LIGHTCURVE ANALYSIS AT CS3-PALMER DIVIDE STATION: 2017 OCTOBER-DECEMBER)(20 NEAs)
[5]	ESA Aegis	ESA orbit determination and impact monitoring system
[6]	EARN	1.) Joseph R. Masiero et al 2020 Planet. Sci. J. 1 5

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

12753

Unit

Source

[1]

Unobserved

Value

771

Unit

Source

[1]

Normalized RMS of residuals

Value

0.426327

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1989-10-29.40625

Unit

Source

[2]

Last Observation

Value

2024-09-28.72148

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

3702 (44)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2024-06-26

Unit

Source

[3]

Last Observation

Value

2024-06-29

Unit

Source

[3]

Delay (Discarded)

Value

3 (1)

Unit

Source

[1]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

3 (1)

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

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Max residual (arcsec):

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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 415029 2011UL21 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	1990-06-21 17:26	< 1 min	0.0968437	0.0968418	0.0000006
EARTH	2024-06-27 20:14	< 1 s	0.0443937	0.0443937	0.0000000
EARTH	2089-06-25 03:47	< 1 min	0.0178233	0.0178226	0.0000002
EARTH	2123-07-01 02:50	2.2	0.0992351	0.0991435	0.0000306

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
37.98958730	169.83422922	0.01657227	MINIMUM
315.01806491	8.00085601	0.26642674	MINIMUM
354.26671683	82.38205912	0.57557739	SADDLE
358.51384890	273.54830336	1.65968950	SADDLE
177.97696075	278.19970515	2.73567360	SADDLE
181.90595345	100.32142189	4.38157400	MAXIMUM

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MOID Plots

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