Asteroids

2021GB4 help

Last update: 2024-04-16 14:31 UTC

Orbital Properties

Epoch

60400.0

MJD

Orbit type

Apollo

Perihelion (q)

0.904

Aphelion (Q)

1.264

Eccentricity (e)

0.166

Inclination (i)

24.5

deg

Orbit period (P)

412.1

Earth MOID

0.02272

U parameter

7.3

Next Earth close approach

Date

2030-04-14

Nominal distance (from Earth center)

0.18525

27713443

Maximum Brightness

23.5

mag

Risk

Object is not in risk list

Object is not in priority list

Physical Properties

Absolute Magnitude (H)

24.5

mag

Diameter

30 - 70*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2021-04-07

Observatory

Pan-STARRS 2, Haleakala

Orbit Visualiser

Click the button to start Orbit Visualiser

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

60400.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.083785

1-sigma variation

0.000224

Unit

Eccentricity (e)

Value

0.165906

1-sigma variation

0.000156

Unit

Inclination (i)

Value

24.4545

1-sigma variation

0.0163

Unit

Long. of Ascending Node (Ω)

Value

198.4633

1-sigma variation

0.0008

Unit

Arg. of Perihelion (ω)

Value

80.5603

1-sigma variation

0.0405

Unit

Mean Anomaly (M)

Value

166.74291

1-sigma variation

0.24052

Unit

Perihelion distance

Value

0.903979

1-sigma variation

Unit

Aphelion distance

Value

1.263591

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.024688

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.086027

1-sigma variation

Unit

MOID

Value

0.022718

1-sigma variation

Unit

Orbit Period

Value

412.1098

1-sigma variation

Unit

U parameter

Value

7.3

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	4.99857E-8	3.48356E-8	3.64287E-6	-1.74371E-7	-9.04481E-6	-5.37746E-5
e	3.48356E-8	2.42779E-8	2.53883E-6	-1.21525E-7	-6.30330E-6	-3.74762E-5
i	3.64287E-6	2.53883E-6	2.65524E-4	-1.27099E-5	-6.59145E-4	-3.91902E-3
Ω	-1.74371E-7	-1.21525E-7	-1.27099E-5	6.08394E-7	3.15508E-5	1.87590E-4
ω	-9.04481E-6	-6.30330E-6	-6.59145E-4	3.15508E-5	1.63667E-3	9.73040E-3
M	-5.37746E-5	-3.74762E-5	-3.91902E-3	1.87590E-4	9.73040E-3	5.78508E-2

Date of computation: 2024-02-21 14:29 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

24.547

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

30 - 70*

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

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

Unit

Source

[1]

Unobserved

Value

1100

Unit

Source

[1]

Normalized RMS of residuals

Value

0.59077

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2021-04-07.25311

Unit

Source

[2]

Last Observation

Value

2021-04-12.81389

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

59 (2)

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 2021GB4 from 1950 to 2124

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possibile distance in au	Distance uncert. in au
EARTH	1950-04-03 19:46	975.1	0.1799125	0.1160567	0.0213608
EARTH	1959-04-08 13:33	> 1 d	0.0485420	0.0219617	0.0320659
EARTH	1968-04-10 12:22	> 1 d	0.0538895	0.0222090	0.0626630
EARTH	1977-04-13 16:44	1425.5	0.1768274	0.0232956	0.0636668
EARTH	1986-10-08 06:05	719.6	0.1242158	0.0807137	0.0384405
EARTH	1995-10-08 08:53	316.8	0.0801126	0.0777985	0.0083792
EARTH	2004-10-09 03:31	624.6	0.1653087	0.1025484	0.0236335
EARTH	2012-04-06 10:42	774.2	0.0944563	0.0461260	0.0166418
EARTH	2021-04-10 04:32	< 1 min	0.0323439	0.0322775	0.0000221
EARTH	2030-04-14 04:59	355.2	0.1852529	0.1344880	0.0169750
EARTH	2039-10-08 08:27	176.1	0.0959861	0.0790283	0.0179411
EARTH	2048-10-08 10:25	837.5	0.1209082	0.0786994	0.0361527
EARTH	2056-04-05 16:29	> 1 d	0.1215637	0.0222016	0.0572313
EARTH	2065-04-10 14:00	> 1 d	0.0402686	0.0231467	0.0463952
EARTH	2074-10-09 14:46	863.2	0.1861637	0.1215176	0.0235359
EARTH	2083-10-08 12:29	26.9	0.0789400	0.0768872	0.0009561
EARTH	2091-04-04 17:48	> 1 d	0.1748317	0.0789064	0.0322944
EARTH	2100-04-11 02:29	> 1 d	0.0315932	0.0235443	0.0406048
EARTH	2109-10-09 19:10	> 1 d	0.1594036	0.0874346	0.0900614
EARTH	2118-10-09 22:59	> 1 d	0.1154686	0.0788004	0.1064943

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