Asteroids

420591 2012HF31 help

Last update: 2025-09-10 00:30 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.866

Aphelion (Q)

2.241

Eccentricity (e)

0.443

Inclination (i)

9.1

deg

Orbit period (P)

707.3

Earth MOID

0.06799

U parameter

0.0

Next Earth close approach

Date

2047-10-08

Nominal distance (from Earth center)

0.16395

24526512

Maximum Brightness

21.3

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

19.5

mag

Diameter

300 - 800*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2012-04-24

Observatory

Pan-STARRS 1, Haleakala

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

61000.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.553656

1-sigma variation

6.520E-9

Unit

Eccentricity (e)

Value

0.442573

1-sigma variation

3.621E-8

Unit

Inclination (i)

Value

9.1059

1-sigma variation

5.857E-6

Unit

Long. of Ascending Node (Ω)

Value

325.7120

1-sigma variation

3.147E-5

Unit

Arg. of Perihelion (ω)

Value

30.3759

1-sigma variation

3.283E-5

Unit

Mean Anomaly (M)

Value

259.91454

1-sigma variation

0.00001

Unit

Perihelion distance

Value

0.866050

1-sigma variation

Unit

Aphelion distance

Value

2.241262

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.108965

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

1.032764

1-sigma variation

Unit

MOID

Value

0.067989

1-sigma variation

Unit

Orbit Period

Value

707.3441

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	4.25094E-17	-2.65953E-17	-4.20248E-16	-5.53382E-14	6.40699E-14	-6.36404E-14
e	-2.65953E-17	1.31116E-15	1.61686E-14	-1.61163E-13	4.74719E-16	1.35646E-13
i	-4.20248E-16	1.61686E-14	3.43020E-11	-8.53175E-11	8.31751E-11	-9.78346E-13
Ω	-5.53382E-14	-1.61163E-13	-8.53175E-11	9.90354E-10	-1.00820E-9	1.23532E-10
ω	6.40699E-14	4.74719E-16	8.31751E-11	-1.00820E-9	1.07765E-9	-1.63215E-10
M	-6.36404E-14	1.35646E-13	-9.78346E-13	1.23532E-10	-1.63215E-10	1.11849E-10

Date of computation: 2025-09-10 00:30 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

[1]

Taxonomy (all)

Value

Unit

Source

[2]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

19.459

Unit

mag

Source

[3]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[3]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[4]

Diameter

Value

300 - 800*

Unit

Source

[4]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Radar R

Unit

Source

[5]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Alexey V. Sergeyev and Benoit Carry A&A, 652 (2021) A59
[2]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[3]	ESA Aegis	ESA orbit determination and impact monitoring system
[4]	Estimation	Estimated from absolute magnitude
[5]	EARN	1.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

9151

Unit

Source

[1]

Unobserved

Value

245

Unit

Source

[1]

Normalized RMS of residuals

Value

0.458756

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2000-02-12.411496

Unit

Source

[2]

Last Observation

Value

2025-03-03.322141

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

175 (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

2018-08-09

Unit

Source

[3]

Last Observation

Value

2018-08-13

Unit

Source

[3]

Delay (Discarded)

Value

0 (0)

Unit

Source

[-]

Doppler (Discarded)

Value

2 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

2 (0)

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

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 420591 2012HF31 from 1950 to 2125

Body	Date in UTC	Time uncert. in min	Nominal distance in au	Min. possible distance in au	Distance uncert. in au
EARTH	1956-09-21 05:31	< 1 min	0.1596235	0.1596229	0.0000002
EARTH	1958-07-16 06:28	< 1 min	0.1177504	0.1177466	0.0000013
EARTH	1985-11-13 05:19	< 1 min	0.1612862	0.1612852	0.0000003
EARTH	1987-08-21 18:00	< 1 min	0.1194496	0.1194480	0.0000005
EARTH	2016-10-25 04:42	< 1 min	0.1583500	0.1583497	0.0000001
EARTH	2018-08-01 09:37	< 1 s	0.0720699	0.0720697	0.0000001
EARTH	2047-10-08 12:07	< 1 min	0.1639496	0.1639493	0.0000001
EARTH	2049-07-23 01:28	< 1 min	0.0749999	0.0749984	0.0000005
EARTH	2076-11-18 19:50	< 1 min	0.1782328	0.1782288	0.0000013
EARTH	2078-08-31 07:45	1.2	0.1363608	0.1363578	0.0000010
EARTH	2107-11-02 18:13	< 1 min	0.1560293	0.1560284	0.0000003
EARTH	2109-08-06 12:03	< 1 min	0.0795595	0.0795553	0.0000014

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
326.41375019	202.68482780	0.06716276	MINIMUM
30.46829024	301.86084361	0.15445212	MINIMUM
10.24388145	270.98305749	0.16366402	SADDLE
180.22230298	73.28072586	1.25178069	SADDLE
358.58750032	72.31272256	1.85962447	SADDLE
178.80722298	252.40468370	3.24367977	MAXIMUM

Download:

MOID Plots

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