Asteroids

3103 Eger help

Last update: 2026-09-29 13:00 UTC

Orbital Properties

Epoch

61400.0

MJD

Orbit type

Apollo

Perihelion (q)

0.907

Aphelion (Q)

1.901

Eccentricity (e)

0.354

Inclination (i)

20.9

deg

Orbit period (P)

607.6

Earth MOID

0.08066

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)

15.3

mag

Diameter

1780

Taxonomic type

Rotation period (T)

5.710

Discovery Information

Discovery Date

1982-01-20

Observatory

Piszkesteto Stn. (Konkoly)

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

61400.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.403913

1-sigma variation

3.273E-10

Unit

Eccentricity (e)

Value

0.354064

1-sigma variation

1.280E-8

Unit

Inclination (i)

Value

20.9312

1-sigma variation

2.597E-6

Unit

Long. of Ascending Node (Ω)

Value

129.7293

1-sigma variation

3.788E-6

Unit

Arg. of Perihelion (ω)

Value

254.1116

1-sigma variation

4.387E-6

Unit

Mean Anomaly (M)

Value

58.10978

1-sigma variation

2.560E-6

Unit

Perihelion distance

Value

0.906838

1-sigma variation

Unit

Aphelion distance

Value

1.900987

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.374730

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.106209

1-sigma variation

Unit

MOID

Value

0.080659

1-sigma variation

Unit

Orbit Period

Value

607.5871

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.07123E-19	2.88617E-18	1.41714E-16	-3.87893E-16	-7.23720E-17	4.02804E-17
e	2.88617E-18	1.63764E-16	-1.00348E-15	-1.56634E-15	-4.86505E-15	1.95945E-15
i	1.41714E-16	-1.00348E-15	6.74477E-12	1.27646E-12	-9.21891E-13	-8.74388E-14
Ω	-3.87893E-16	-1.56634E-15	1.27646E-12	1.43501E-11	-1.27351E-11	8.69907E-13
ω	-7.23720E-17	-4.86505E-15	-9.21891E-13	-1.27351E-11	1.92417E-11	-6.18319E-12
M	4.02804E-17	1.95945E-15	-8.74388E-14	8.69907E-13	-6.18319E-12	6.55413E-12

Date of computation: 2026-09-29 13:00 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

5.706

5.710

Unit

Source

[7]

[1]

Quality

Value

Unit

Source

[7]

Amplitude

Value

0.55

0.72-0.9

Unit

mag

Source

[1]

[7]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

212

Unit

Source

[1]

Spinvector B

Value

Unit

Source

[1]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[3]

[4]

Taxonomy (all)

Value

E;Xe

Unit

Source

[5]

[6]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

15.269

15.653

Unit

mag

Source

[8]

[9]

Slope Parameter (G)

Value

0.42

0.15**

Unit

Source

[10]

[8]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.42

Unit

Source

[12]

Diameter

Value

1780

Unit

Source

[11]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.76

0.47

Unit

B-V

V-R

Source

[13]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Visual S

Radar R

Unit

Source

[14]

[15]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Near-Earth Asteroid Lightcurve Analysis at the Center for Solar System Studies: 2019 March-July, B.D. Warner
[2]	EARN	1.) Durech, J. et al. (2012) Astron. Astrophy 547, A10. (Analysis of the rotation period of asteroids (1865) Cerberus, (2100) Ra-Shalom, and (3103) Eger - search for the YORP effect)
[3]	EARN	1.) Alexey V. Sergeyev and Benoit Carry A&A, 652 (2021) A59
[4]	EARN	1.) Thomas, C.A. et al. (2014) Icarus 228, 217-246. (Physical characterization of Warm Spitzer-observed near-Earth objects)
[5]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[6]	EARN	1.) Tholen, D.J. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1139-1150. 2.) 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.) 3.) 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.) 4.) Lazzarin, M. et al. (2004) Icarus 169, 373-384. (Visible and near-infrared spectroscopic investigation of near-Earth objects at ESO: first results) 5.) Rivkin, A.S. et al. (2005) Icarus 175, 175-180. (Constraining near-Earth object albedos using near-infrared spectroscopy) (1580,3103,29075,2001 ME1, 26760) 6.) Lazzarin, M., Marchi,S. & Magrin, S. (2010) href="http://www.astro.unipd.it/planets/sineo/data.html"> SINEO Database (Spectroscopic Investiation of Near-Earth Objects) 7.) Thomas, C.A. et al. (2011) Astron. J. 142, 85. (ExploreNEOs. V. AVERAGE ALBEDO BY TAXONOMIC COMPLEX IN THE NEAR-EARTH ASTEROID POPULATION) (new albedos data for 118 NEOs)
[7]	EARN	1.) De Sanctis, M.C. et al. (1994) Planet. Space Sci. 42, 859-864. (Photoelectric and CCD observations of 10 asteroids) 3103 2.) Pravec, P. et al. (1998) Icarus 136, 124-153. (Lightcurves of 26 Near-Earth Asteroids)(1943,2063,2100,3103,3122,3200, 3691,3752,4341,4957,5143,5587,7025,7341,7480,7482,7822,8034, 1989UQ,1992CC1,1992QN,1995FX,1997BR,1997GH3,1997GL3,1997SE5) 3.) Wisniewski, W.Z. (1987) Icarus 70, 566-572. (Photometry of six radar target asteroids)1986 DA, 3199, 3103, and 1983 RD. 1986 JK and 1986 RA 4.) Wisniewski, W.Z. (1991) Icarus 90, 117-122. (Physical studies of small asteroids. I - Lightcurves and taxonomy of 10 asteroids) 5.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods" 6.) Krugly, Yu. N. et al. (2002) Proceedings of ACM2002, ESA-SP500, pp. 903-906. (CCD photometry of Near-Earth asteroids in 2001) (rot.per. for 719,1916,26760,33342 2001 MF1; LCs for 1620,3103,5587,1999 KW4) 7.) Gaffey, M.J. et al. (1992) Icarus 100, 95-109. (Relationship of E-type Apollo asteroid 3103 (1982 BB) to the enstatite achondrite meteorites and the Hungaria asteroids) 8.) Velichko, F.P. et al. (1989) Astron.Tsirk 1553, 37-38. 9.) Kaasalainen, M. et al. (2002) Icarus 159, 369-395. (Models of Twenty Asteroids from Photometric Data;..1036,3103,6053, ..) 10.) Krugly, Yu. N. et al. (2006) IAU Symp. 236, 385-390. (Kharkiv study of near-Earth asteroids) (1036,1627,1685, 1862,1980,3103,3200,4179,6611,8567,11405,13553,23187,54509, 66251,100085,1999LF6,2004XP14,2005AB,2006CV69,2006BQ6) 11.) Warner, B.D. (2014) MPB 41, 213-224. (NEAR-EARTH ASTEROID LIGHTCURVE ANALYSIS AT CS3-PALMER DIVIDE STATION: 2014 MARCH-JUNE) (38 NEA lightcurve data) 12.) Warner, B.D. (2016) MPB 43, 311-319. (NEAR-EARTH ASTEROID LIGHTCURVE ANALYSIS AT CS3-PALMER DIVIDE STATION: 2016 APRIL-JULY)(31 NEAs)
[8]	ESA Aegis	ESA orbit determination and impact monitoring system
[9]	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) 2.) Wisniewski, W.Z. (1987) Icarus 70, 566-572. (Photometry of six radar target asteroids)1986 DA, 3199, 3103, and 1983 RD. 1986 JK and 1986 RA 3.) Pravec, P. et al. (1998) Icarus 136, 124-153. (Lightcurves of 26 Near-Earth Asteroids)(1943,2063,2100,3103,3122,3200, 3691,3752,4341,4957,5143,5587,7025,7341,7480,7482,7822,8034, 1989UQ,1992CC1,1992QN,1995FX,1997BR,1997GH3,1997GL3,1997SE5) 4.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods"
[10]	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) 2.) Pravec, P. et al. (1998) Icarus 136, 124-153. (Lightcurves of 26 Near-Earth Asteroids)(1943,2063,2100,3103,3122,3200, 3691,3752,4341,4957,5143,5587,7025,7341,7480,7482,7822,8034, 1989UQ,1992CC1,1992QN,1995FX,1997BR,1997GH3,1997GL3,1997SE5)
[11]	EARN	1.) Harris(DLR), A.W. et al. (2011) Astron. J. 141, 75. (ExploreNEOs. II. THE ACCURACY OF THE WARM SPITZER NEAR-EARTH OBJECT SURVEY) 2.) Trilling, D.E. et al. (2010) Astron. J. 140, 770-784. (EXPLORENEOs. I. DESCRIPTION AND FIRST RESULTS FROM THE WARM SPITZER NEAR-EARTH OBJECT SURVEY) (diameters & albedos for 101 NEOs) 3.) Wisniewski, W.Z. (1991) Icarus 90, 117-122. (Physical studies of small asteroids. I - Lightcurves and taxonomy of 10 asteroids) 4.) Veeder, G.J. et al. (1989) Astron. J. 97, 1211-1219. (Radiometry of near-earth asteroids) 5.) Usui, F. et al. (2011) Pub. Astron. Soc. Japan 63, 1117-1138. (Asteroid Catalog Using AKARI: AKARI/IRC Mid-Infrared Asteroid Survey)
[12]	EARN	1.) Thomas, C.A. et al. (2011) Astron. J. 142, 85. (ExploreNEOs. V. AVERAGE ALBEDO BY TAXONOMIC COMPLEX IN THE NEAR-EARTH ASTEROID POPULATION) (new albedos data for 118 NEOs) 2.) Trilling, D.E. et al. (2010) Astron. J. 140, 770-784. (EXPLORENEOs. I. DESCRIPTION AND FIRST RESULTS FROM THE WARM SPITZER NEAR-EARTH OBJECT SURVEY) (diameters & albedos for 101 NEOs) 3.) Veeder, G.J. et al. (1989) Astron. J. 97, 1211-1219. (Radiometry of near-earth asteroids) 4.) Rivkin, A.S. et al. (2005) Icarus 175, 175-180. (Constraining near-Earth object albedos using near-infrared spectroscopy) (1580,3103,29075,2001 ME1, 26760) 5.) Harris(DLR), A.W. et al. (2011) Astron. J. 141, 75. (ExploreNEOs. II. THE ACCURACY OF THE WARM SPITZER NEAR-EARTH OBJECT SURVEY) 6.) Usui, F. et al. (2011) Pub. Astron. Soc. Japan 63, 1117-1138. (Asteroid Catalog Using AKARI: AKARI/IRC Mid-Infrared Asteroid Survey)
[13]	EARN	1.) Dandy, C.L.; Fitzsimmons, A.; Collander-Brown, S.J. (2003) Icarus 163, 363-373. (Optical colors of 56 near-Earth objects: trends with size and orbit)
[14]	EARN	1.) Lazzarin, M. et al. (2004) Icarus 169, 373-384. (Visible and near-infrared spectroscopic investigation of near-Earth objects at ESO: first results) 2.) 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.) 3.) 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.) 4.) Fevig. R.A. and U. Fink (2007) Icarus 188, 175-188. (Spectral observations of 19 weathered and 23 fresh NEAs and their correlations with orbital parameters)(433,1036, 1627,1685,1862,1866,1943,1980,3103,3122,3199,3671,4183,4341, 4954,5587,5751,5836,6037,7358,7482,7753,7822,7977,8201, 10563,11066,13651,13651,19356,20236,20255,35107,85490, J97GD32,J97UH9,J97US9,J98HE3,J98HT31,J98ME3,J98MS2,K04LC2) 5.) Rivkin, A.S. et al. (2005) Icarus 175, 175-180. (Constraining near-Earth object albedos using near-infrared spectroscopy) (1580,3103,29075,2001 ME1, 26760) 6.) Lazzarin, M., Marchi,S. & Magrin, S. (2010) href="http://www.astro.unipd.it/planets/sineo/data.html"> SINEO Database (Spectroscopic Investiation of Near-Earth Objects) 7.) Thomas, C.A. et al. (2014) Icarus 228, 217-246. (Physical characterization of Warm Spitzer-observed near-Earth objects)
[15]	EARN	1.) Benner, L.A.M. et al. (1996) B.A.A.S. 28, 1105. 10.41. (Radar Observations of Near-Earth Asteroids 2062 Aten, 2101 Adonis, 3103 Eger, 4544 Xanthus, and 1992 QN) 2.) Benner, L.A.M. et al. (1997) Icarus 130, 296-312. (Radar Detection of Near-Earth Asteroids 2062 Aten, 2101 Adonis, 3103 Eger, 4544 Xanthus, and 1992 QN) 3.) Ostro, S.J. et al. (1991) Astron. J. 102, 1490-1502. (Asteroid radar astrometry)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

16322

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.31905

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1982-01-20.02202

Unit

Source

[2]

Last Observation

Value

2026-09-28.393469

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

8941 (13)

Unit

Source

[1]

Radar Summary

First Observation
Last Observation
Delay (Discarded)
Doppler (Discarded)
Total Optical Observations (Discarded)

Radar

Value

Unit

Source

First Observation

Value

1986-07-18

Unit

Source

[3]

Last Observation

Value

1996-07-30

Unit

Source

[3]

Delay (Discarded)

Value

1 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

3 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

4 (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

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Max residual (arcsec):

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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.

Close Approaches for 3103 Eger 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	1981-08-03 06:46	< 1 s	0.1765070	0.1765068	0.0000001
EARTH	1986-08-05 01:54	< 1 s	0.1439297	0.1439296	0.0000001
EARTH	1991-08-06 08:08	< 1 s	0.1242354	0.1242353	0.0000000
EARTH	1996-08-06 02:29	< 1 s	0.1150862	0.1150862	0.0000000
EARTH	2001-08-06 07:31	< 1 s	0.1161238	0.1161237	0.0000000
EARTH	2006-08-05 21:46	< 1 s	0.1283862	0.1283861	0.0000000
EARTH	2011-08-04 23:17	< 1 s	0.1528266	0.1528265	0.0000000
EARTH	2016-08-02 13:23	< 1 s	0.1894140	0.1894139	0.0000000

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
311.49230473	214.61805193	0.08065858	MINIMUM
57.54776432	359.49153293	0.23930463	MINIMUM
10.09878682	296.32043499	0.35448544	SADDLE
183.74768091	102.07207373	1.02130675	SADDLE
0.13650481	101.08404373	1.87950944	SADDLE
176.55744361	276.80757814	2.85813369	MAXIMUM

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MOID Plots

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