Asteroids

31345 1998PG help

Last update: 2026-07-30 09:40 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Amor

Perihelion (q)

1.227

Aphelion (Q)

2.804

Eccentricity (e)

0.391

Inclination (i)

6.5

deg

Orbit period (P)

1045.0

Earth MOID

0.23355

U parameter

0.0

Next Earth close approach

Date

Nominal distance (from Earth center)

Maximum Brightness

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

17.5

mag

Diameter

820

Taxonomic type

Rotation period (T)

2.516

Discovery Information

Discovery Date

1998-08-03

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

2.015289

1-sigma variation

1.030E-9

Unit

Eccentricity (e)

Value

0.391314

1-sigma variation

2.323E-8

Unit

Inclination (i)

Value

6.5036

1-sigma variation

2.699E-6

Unit

Long. of Ascending Node (Ω)

Value

222.6835

1-sigma variation

2.292E-5

Unit

Arg. of Perihelion (ω)

Value

156.1811

1-sigma variation

2.330E-5

Unit

Mean Anomaly (M)

Value

237.61970

1-sigma variation

3.957E-6

Unit

Perihelion distance

Value

1.226678

1-sigma variation

Unit

Aphelion distance

Value

2.803900

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

1.650107

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.264814

1-sigma variation

Unit

MOID

Value

0.233551

1-sigma variation

Unit

Orbit Period

Value

1044.9714

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.06160E-18	1.29848E-18	1.26432E-16	-5.67894E-16	2.26411E-15	-2.71468E-15
e	1.29848E-18	5.39513E-16	-7.63943E-15	-1.92122E-14	-4.15747E-15	2.44170E-14
i	1.26432E-16	-7.63943E-15	7.28306E-12	-2.00045E-11	2.12042E-11	-1.17953E-12
Ω	-5.67894E-16	-1.92122E-14	-2.00045E-11	5.25097E-10	-5.19481E-10	-1.40551E-12
ω	2.26411E-15	-4.15747E-15	2.12042E-11	-5.19481E-10	5.42964E-10	-1.67157E-11
M	-2.71468E-15	2.44170E-14	-1.17953E-12	-1.40551E-12	-1.67157E-11	1.56558E-11

Date of computation: 2026-07-30 09:40 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

2.516

Unit

Source

[6]

Quality

Value

2,B

Unit

Source

[6]

Amplitude

Value

0.11

Unit

mag

Source

[6]

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]

[2]

[3]

Taxonomy (all)

Value

Sq;Q

Unit

Source

[4]

[5]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

17.523

17.64

Unit

mag

Source

[7]

[8]

Slope Parameter (G)

Value

0.23

0.15**

Unit

Source

[8]

[7]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.251

Unit

Source

[9]

Diameter

Value

820

Unit

Source

[9]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.4814
0.1328
0.44
0.6142
0.6383
0.81
-0.113
0.1999

Unit

g-r

r-z

V-R

g-z

g-i

B-V

i-z

r-i

Source

[2]

[10]

[2]

[10]

[2]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Visual S

Unit

Source

[1]

Satellites

Satellites

Value

Unit

Source

Satellites

Value

Binary Child 1

Unit

Source

[5]

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Sources

No.	Name	Additional
[1]	EARN	1.) Binzel, R.P. et al. (2004) Icarus 170, 259-294. (Observed spectral properties of near-Earth objects: results for population distribution, source regions, and space weathering processes.)
[2]	EARN	1.) A. V. Sergeyev, B. Carry et al A&A, 658 (2022) A109
[3]	EARN	1.) Michaël Marsset et al 2022 AJ 163 165
[4]	EARN	1.) Bus, S.J. & Binzel, R.P. (2002) Icarus 158,106-145. (Phase II of the Small Main-Belt Asteroid Spectrographic Survey: A Feature-Based Taxonomy.) 2.) Binzel, R.P. et al. (2004) Icarus 170, 259-294. (Observed spectral properties of near-Earth objects: results for population distribution, source regions, and space weathering processes.) 3.) Whiteley, R.J. (2001) PhD. Thesis, University of Hawaii. (A Compositional and Dynamical Survey of the Near-Earth Asteroids)
[5]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[6]	EARN	1.) Pravec, P. et al. (2000) Icarus 146, 190-203. (Two-period lightcurves of 1996 FG3, 1998 PG and (5407) 1992 AX: One probable and two possible binary asteroids.) 2.) Kiss, L.L. et al. (1999) Astron. Astrophys. Suppl. 140, 21-28. (CCD photometry and new models of 5 minor planets) (..1627..) 3.) Pravec, P. et al. (2006) Icarus 181, 63-93. (Photometric survey of binary near-Earth asteroids)
[7]	ESA Aegis	ESA orbit determination and impact monitoring system
[8]	EARN	1.) Pravec, P. et al. (2012) Icarus 221, 365-387 (Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations)
[9]	EARN	1.) Joseph R. Masiero et al 2020 Planet. Sci. J. 1 5
[10]	EARN	1.) Pravec, P. et al. (2000) Icarus 146, 190-203. (Two-period lightcurves of 1996 FG3, 1998 PG and (5407) 1992 AX: One probable and two possible binary asteroids.)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

17386

Unit

Source

[1]

Unobserved

Value

179

Unit

Source

[1]

Normalized RMS of residuals

Value

0.508303

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1978-10-07.37153

Unit

Source

[2]

Last Observation

Value

2026-05-14.410529

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

1719 (10)

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):

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Plot

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

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Note: Ephemerides requests are limited to a maximum of 1000 points and a final date not exceeding 2040/12/31 00:00.

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
0.87305695	276.68356428	0.23355076	MINIMUM
178.84103090	93.49250177	1.80436776	SADDLE
357.86116873	92.15564114	2.22704597	SADDLE
179.37569690	273.84558941	3.80192670	MAXIMUM

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