Asteroids

2021WC1

Last update: 2022-01-23 14:32 UTC

Orbital Properties

Epoch

59600.0

MJD

Orbit type

Apollo

Perihelion (q)

0.812

Aphelion (Q)

1.94

Eccentricity (e)

0.41

Inclination (i)

deg

Orbit period (P)

589.6

days

Earth MOID

0.00117

Next Earth close approach

Date

2042-11-21

Nominal distance (from Earth center)

0.10906

16314611

Maximum Brightness

126.6

Orbit Visualiser

Click the button to start Orbit Visualiser

Risk

Object is in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

28.5

Diameter

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-11-27

Observatory

Mt. Lemmon Survey

External links

Proper elements

Epoch

Near present day

Near middle of observation arc

Orbit properties

Epoch
Semimajor Axis
Eccentricity (e)
Inclination (i)
Ascending Node (Ω)
Arg. of Perihelion (ω)
Mean Anomaly (M)
Perihelion
Aphelion
Asc. Node-Earth Sep.
Desc. Node-Earth Sep.
MOID
Orbit Period

Value

1-sigma variation

Unit

Epoch

Value

59600.0

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.38

1-sigma variation

4.14177E-4

Unit

Eccentricity (e)

Value

0.410149716531763

1-sigma variation

2.2661E-4

Unit

Inclination (i)

Value

9.02

1-sigma variation

4.044E-3

Unit

Ascending Node (Ω)

Value

246.72

1-sigma variation

2.846E-4

Unit

Arg. of Perihelion (ω)

Value

246.46

1-sigma variation

4.062E-4

Unit

Mean Anomaly (M)

Value

3.31

1-sigma variation

2.907E-3

Unit

Perihelion

Value

8.117E-1

1-sigma variation

Unit

Aphelion

Value

1.94

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

3.567E-1

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-2.628E-3

1-sigma variation

Unit

MOID

Value

1.173E-3

1-sigma variation

Unit

Orbit Period

Value

589.61

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.71543E-7	9.38525E-8	1.66017E-6	-5.58529E-8	-5.74953E-8	1.20180E-6
e	9.38525E-8	5.13523E-8	9.07300E-7	-3.00790E-8	-3.06361E-8	6.57144E-7
i	1.66017E-6	9.07300E-7	1.63568E-5	-6.74756E-7	-7.05037E-7	1.17163E-5
Ω	-5.58529E-8	-3.00790E-8	-6.74756E-7	8.09812E-8	9.14954E-8	-4.32019E-7
ω	-5.74953E-8	-3.06361E-8	-7.05037E-7	9.14954E-8	1.64993E-7	-4.64243E-7
M	1.20180E-6	6.57144E-7	1.17163E-5	-4.32019E-7	-4.64243E-7	8.44936E-6

Date of computation: 2021-11-27 22:00 UTC

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

28.516

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

Unit

Source

[-]

Diameter

Value

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

[-]

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Sources

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

**Estimated value

Observational Information

Arc Length
Unobserved

Arc Information

Value

Unit

Source

Arc Length

Value

Unit

days

Source

[1]

Unobserved

Value

Unit

days

Source

[1]

Astrometry Summary

RMS of Residuals
First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

RMS of Residuals

Value

0.543508

Unit

arcseconds

Source

[1]

First Observation

Value

2021-11-27.184031

Unit

Source

[2]

Last Observation

Value

2021-11-27.84946

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

22 (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

[3]

Last Observation

Value

Unit

Source

[3]

Delay (Discarded)

Value

0 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[1]

Note: The ASCII file is in a format suitable for OrbFit input.

Sources

No.	Name	Additional
[1]	ESA ODIM	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 2021WC1 from 1950 to

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possibile distance in au	Distance uncert. in au
EARTH	1954-03-20 02:13	> 1 mo	0.1864311	0.0981618	0.1650509
EARTH	1966-12-09 03:28	> 1 mo	0.0917348	0.0028836	0.2706055
EARTH	1975-04-18 22:50	> 1 w	0.0978330	0.0978330	0.0033948
EARTH	2000-11-24 16:45	> 1 d	0.0477850	0.0017513	0.0541405
EARTH	2021-11-28 15:03	< 1 min	0.0013631	0.0013631	0.0000005
EARTH	2042-11-21 11:14	> 1 d	0.1090564	0.0009153	0.0545286
EARTH	2059-04-24 09:02	> 1 d	0.1361242	0.1034342	0.0284333
EARTH	2071-12-28 08:16	> 1 d	0.1604857	0.1014441	0.0160604
EARTH	2080-04-17 13:11	573.1	0.1047583	0.1028821	0.0010550
EARTH	2092-12-11 12:22	> 1 d	0.1047885	0.0005968	0.0178420
EARTH	2101-04-16 13:39	> 1 d	0.1144710	0.1026459	0.0136832
EARTH	2113-12-14 21:56	> 1 w	0.1146369	0.0011111	0.0467198

Download as:

2021WC1

Date in UTC	MJD	σ	Distance ± Width in RE	Stretching in RE/σ	IP	Exp. energy	PS
2063-11-29.405	74887.405	-4.556	1.23 ± 0.008	1.79E5	9.20E-11	1.15E-12	-11.66
2069-11-28.905	77078.905	1.916	0.48 ± 0.011	1.24E6	1.35E-7	1.71E-9	-8.55
2070-11-29.154	77444.154	2.036	0.47 ± 0.008	1.01E6	1.30E-7	1.65E-9	-8.57
2070-11-29.154	77444.154	2.036	0.47 ± 0.008	1.07E6	1.23E-7	1.55E-9	-8.60
2077-11-28.919	80000.919	1.907	0.57 ± 0.008	7.92E5	2.08E-7	2.63E-9	-8.43
2079-11-29.406	80731.406	-4.344	1.04 ± 0.008	1.14E6	5.20E-11	6.50E-13	-12.05
2079-11-29.407	80731.407	1.480	0.04 ± 0.000	3.08E7	1.21E-8	1.52E-10	-9.68
2079-11-29.426	80731.426	-2.512	1.23 ± 0.007	1.05E5	2.15E-7	2.70E-9	-8.43


Based on 22 optical observations (of which 0 are rejected as outliers) from 2021/11/27.184 to 2021/11/27.849.
Coordinates are given on the Target Plane.
Unit is one Earth radius, but impact cross section has radius between 1.39 and 1.40 Earth radii. Coordinates for LOV = EQU scaled= 1 second= F.
AstOD software version= 2.0, Date of computation=20211127 222002.217 UTC.

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