Asteroids

2021VC4 help

Last update: 2026-07-30 14:25 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Aten

Perihelion (q)

0.560

Aphelion (Q)

1.211

Eccentricity (e)

0.368

Inclination (i)

2.4

deg

Orbit period (P)

304.4

Earth MOID

0.01359

U parameter

6.3

Next Earth close approach

Date

2026-11-03

Nominal distance (from Earth center)

0.01537

2299513

Maximum Brightness

20.4

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

26.8

mag

Diameter

12 - 26*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-11-07

Observatory

University of Arizona Mt. Lemmon 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

0.885512

1-sigma variation

0.000028

Unit

Eccentricity (e)

Value

0.367530

1-sigma variation

0.000514

Unit

Inclination (i)

Value

2.3642

1-sigma variation

0.0044

Unit

Long. of Ascending Node (Ω)

Value

240.1835

1-sigma variation

0.0116

Unit

Arg. of Perihelion (ω)

Value

32.2131

1-sigma variation

0.0142

Unit

Mean Anomaly (M)

Value

274.20889

1-sigma variation

0.12955

Unit

Perihelion distance

Value

0.560060

1-sigma variation

Unit

Aphelion distance

Value

1.210964

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.427912

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.123956

1-sigma variation

Unit

MOID

Value

0.013587

1-sigma variation

Unit

Orbit Period

Value

304.3619

1-sigma variation

Unit

U parameter

Value

6.3

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	7.84672E-10	2.90314E-9	6.90368E-8	-2.90043E-7	3.93328E-7	-3.19314E-6
e	2.90314E-9	2.63751E-7	2.07721E-6	-3.52942E-6	2.30485E-6	-4.27740E-5
i	6.90368E-8	2.07721E-6	1.92540E-5	-4.35871E-5	4.10879E-5	-5.03845E-4
Ω	-2.90043E-7	-3.52942E-6	-4.35871E-5	1.33434E-4	-1.55918E-4	1.48077E-3
ω	3.93328E-7	2.30485E-6	4.10879E-5	-1.55918E-4	2.02207E-4	-1.70447E-3
M	-3.19314E-6	-4.27740E-5	-5.03845E-4	1.48077E-3	-1.70447E-3	1.67826E-2

Date of computation: 2026-07-30 14:25 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

26.818

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

12 - 26*

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

Unit

Source

[-]

Download this part as:

Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	Estimation	Estimated from absolute magnitude

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

Unit

Source

[1]

Unobserved

Value

1804

Unit

Source

[1]

Normalized RMS of residuals

Value

0.604633

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-11-07.157658

Unit

Source

[2]

Last Observation

Value

2021-11-08.82938

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

15 (1)

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

Initial Date: *

Final Date: *

Normalised Only accepted

Max residual (arcsec):

* - these fields are required

Plot

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

One line per time step

Time step:*

* - these fields are required

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 2021VC4 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	1952-11-04 19:43	528.6	0.0729763	0.0573749	0.0052357
EARTH	1957-11-11 19:26	> 1 d	0.1263034	0.1099420	0.0054639
EARTH	1962-11-23 12:59	> 1 d	0.1732493	0.1611832	0.0040272
EARTH	1988-01-20 11:30	> 1 d	0.1872039	0.1803202	0.0022985
EARTH	1993-01-31 19:58	1099.7	0.1455571	0.1373305	0.0027500
EARTH	1998-02-10 00:57	427.3	0.0942220	0.0856959	0.0028738
EARTH	2001-11-07 15:50	141.4	0.1946292	0.1854378	0.0030643
EARTH	2003-02-13 03:53	75.0	0.0511935	0.0468331	0.0015699
EARTH	2006-11-06 10:34	101.2	0.1515501	0.1445121	0.0023466
EARTH	2008-02-13 17:26	12.6	0.0401395	0.0394220	0.0003340
EARTH	2011-11-05 06:25	72.7	0.0996360	0.0933325	0.0021027
EARTH	2013-02-12 07:24	46.6	0.0725797	0.0678540	0.0015992
EARTH	2016-11-03 10:14	33.3	0.0455337	0.0411243	0.0014784
EARTH	2018-02-11 12:08	47.9	0.1191669	0.1144917	0.0015629
EARTH	2021-11-03 11:04	< 1 min	0.0162351	0.0161635	0.0000239
EARTH	2023-02-11 04:54	70.6	0.1469905	0.1414701	0.0018440
EARTH	2026-11-03 17:29	7.5	0.0153713	0.0138576	0.0006790
EARTH	2028-02-11 22:43	177.4	0.1401887	0.1299183	0.0034364
EARTH	2031-11-04 09:43	147.7	0.0452125	0.0277897	0.0060024
EARTH	2033-02-12 15:37	265.7	0.1002360	0.0809386	0.0065942
EARTH	2036-11-04 21:25	251.3	0.0976510	0.0782985	0.0064672
EARTH	2038-02-14 03:19	144.7	0.0560118	0.0448910	0.0045565
EARTH	2041-11-06 16:52	224.7	0.1473023	0.1324147	0.0049654
EARTH	2043-02-14 18:14	34.6	0.0428502	0.0416523	0.0010468
EARTH	2048-02-13 17:09	386.0	0.0753208	0.0633554	0.0041847
EARTH	2053-02-06 04:21	1150.1	0.1300723	0.1184816	0.0038898
EARTH	2058-01-24 20:46	> 1 d	0.1789754	0.1720385	0.0023173
EARTH	2082-12-02 07:28	1082.4	0.1991448	0.1952007	0.0013150
EARTH	2087-11-22 20:12	> 1 d	0.1694060	0.1607838	0.0028757
EARTH	2092-11-12 17:10	> 1 d	0.1298730	0.1133693	0.0055081
EARTH	2097-11-07 12:20	1364.6	0.0930356	0.0667328	0.0088055
EARTH	2102-11-06 06:49	855.2	0.0598159	0.0250419	0.0119859
EARTH	2107-11-06 05:32	576.3	0.0515589	0.0219622	0.0102998
EARTH	2112-11-06 04:42	337.0	0.0658887	0.0533819	0.0041856
EARTH	2117-11-08 23:00	514.8	0.0951429	0.0863313	0.0029411
EARTH	2122-11-15 04:31	> 1 d	0.1328137	0.1067343	0.0087147

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
109.42803986	297.45692929	0.01358692	MINIMUM
251.83072777	39.81736994	0.04055849	MINIMUM
180.86906289	348.71402138	0.22839887	SADDLE
1.07441926	169.22641162	0.45676677	SADDLE
0.88568464	348.95156342	1.54380930	SADDLE
180.35765175	168.37606595	2.22731776	MAXIMUM

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MOID Plots

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