Asteroids

2005HC4 help

Last update: 2026-06-04 23:11 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.071

Aphelion (Q)

3.564

Eccentricity (e)

0.961

Inclination (i)

8.5

deg

Orbit period (P)

894.9

Earth MOID

0.05915

U parameter

9.0

Next Earth close approach

Date

2032-05-03

Nominal distance (from Earth center)

0.12298

18397287

Maximum Brightness

18.4

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

20.6

mag

Diameter

200 - 500*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2005-04-30

Observatory

Lowell Observatory-LONEOS

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

1.817447

1-sigma variation

0.028271

Unit

Eccentricity (e)

Value

0.961056

1-sigma variation

0.001194

Unit

Inclination (i)

Value

8.5474

1-sigma variation

0.0963

Unit

Long. of Ascending Node (Ω)

Value

62.3819

1-sigma variation

1.0971

Unit

Arg. of Perihelion (ω)

Value

310.4184

1-sigma variation

1.2565

Unit

Mean Anomaly (M)

Value

198.40018

1-sigma variation

64.50270

Unit

Perihelion distance

Value

0.070779

1-sigma variation

Unit

Aphelion distance

Value

3.564115

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.902170

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.643836

1-sigma variation

Unit

MOID

Value

0.059146

1-sigma variation

Unit

Orbit Period

Value

894.9342

1-sigma variation

Unit

U parameter

Value

9.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	7.99264E-4	3.37419E-5	2.72165E-3	-3.10175E-2	3.55238E-2	-1.82357E0
e	3.37419E-5	1.42448E-6	1.14897E-4	-1.30944E-3	1.49968E-3	-7.69843E-2
i	2.72165E-3	1.14897E-4	9.26819E-3	-1.05622E-1	1.20967E-1	-6.20961E0
Ω	-3.10175E-2	-1.30944E-3	-1.05622E-1	1.20372E0	-1.37859E0	7.07683E1
ω	3.55238E-2	1.49968E-3	1.20967E-1	-1.37859E0	1.57888E0	-8.10497E1
M	-1.82357E0	-7.69843E-2	-6.20961E0	7.07683E1	-8.10497E1	4.16060E3

Date of computation: 2026-06-04 23:11 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

20.602

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

200 - 500*

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 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

7713

Unit

Source

[1]

Normalized RMS of residuals

Value

0.62268

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2005-04-30.31003

Unit

Source

[2]

Last Observation

Value

2005-05-11.92802

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

53 (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 2005HC4 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	1956-04-25 23:47	> 1 mo	0.0964384	0.0686770	2.0696305
MERCURY	1971-02-01 01:52	> 1 mo	0.0402310	0.0188276	3.0458567
MERCURY	1990-10-04 18:19	> 1 mo	0.0306225	0.0057616	2.6232604
EARTH	1998-03-09 05:28	> 1 w	0.1511669	0.1407302	0.2418885
MERCURY	2010-05-04 21:54	> 1 w	0.0163769	0.0162975	0.0586578
EARTH	2025-03-05 23:17	> 1 mo	0.1452317	0.1432728	0.3703841
EARTH	2032-05-03 22:29	> 1 mo	0.1229783	0.0579034	2.8123773
MERCURY	2044-09-15 13:35	> 1 mo	0.0465031	0.0102727	8.8414427
MERCURY	2052-01-03 06:06	> 1 mo	0.0138418	0.0122888	3.0617553
EARTH	2059-04-23 03:21	> 1 mo	0.1742653	0.0544120	5.2282333
EARTH	2074-03-08 10:38	> 1 mo	0.1510527	0.1488740	1.1452012
EARTH	2081-05-06 17:41	> 1 mo	0.1689959	0.0519900	6.9058228
MERCURY	2086-05-17 05:34	> 1 mo	0.0446003	0.0121839	14.4832437
MERCURY	2093-09-04 17:56	> 1 mo	0.0436413	0.0091863	9.6459636
EARTH	2108-04-30 16:09	> 1 mo	0.0492819	0.0483227	0.9694794
VENUS	2110-10-25 06:06	> 1 mo	0.0217769	0.0000496	6.0432203
VENUS	2113-04-10 09:56	> 1 mo	0.0033521	0.0015882	1.9371695
VENUS	2115-09-27 07:47	> 1 mo	0.0332398	0.0015891	33.6865443

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
297.74136457	117.10582173	0.05935170	MINIMUM
61.51764877	64.09660735	0.14340451	MINIMUM
356.00365138	257.00660142	0.93242910	SADDLE
356.04990639	77.24639008	1.06911709	SADDLE
179.85028797	91.51151328	2.57188854	SADDLE
179.95990264	271.52724540	4.55935572	MAXIMUM

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MOID Plots

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