Asteroids

2100 Ra-Shalom help

Last update: 2025-11-13 13:00 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Aten

Perihelion (q)

0.469

Aphelion (Q)

1.195

Eccentricity (e)

0.436

Inclination (i)

15.8

deg

Orbit period (P)

277.2

Earth MOID

0.14985

U parameter

0.0

A₂

-4.7

10^-15au/days²

Next Earth close approach

Date

2035-10-15

Nominal distance (from Earth center)

0.19061

28514207

Maximum Brightness

15.5

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

16.3

mag

Diameter

2240

Taxonomic type

Rotation period (T)

19.79

Discovery Information

Discovery Date

1978-09-10

Observatory

Palomar Mountain

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

0.832018

1-sigma variation

6.506E-10

Unit

Eccentricity (e)

Value

0.436495

1-sigma variation

4.839E-9

Unit

Inclination (i)

Value

15.7589

1-sigma variation

6.970E-7

Unit

Long. of Ascending Node (Ω)

Value

170.7633

1-sigma variation

2.264E-6

Unit

Arg. of Perihelion (ω)

Value

356.0816

1-sigma variation

1.711E-6

Unit

Mean Anomaly (M)

Value

249.10867

1-sigma variation

3.858E-6

Unit

Perihelion distance

Value

0.468846

1-sigma variation

Unit

Aphelion distance

Value

1.195190

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.525337

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.186365

1-sigma variation

Unit

MOID

Value

0.149854

1-sigma variation

Unit

Orbit Period

Value

277.2028

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

A₂

Value

-4.73157

1-sigma variation

0.76932

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	4.23279E-19	-2.11198E-18	-2.44729E-16	5.78498E-17	-7.37391E-16	4.07328E-16	4.89797E-10
e	-2.11198E-18	2.34150E-17	1.61047E-15	-2.75265E-15	6.40771E-15	-5.33377E-15	-2.45346E-9
i	-2.44729E-16	1.61047E-15	4.85797E-13	-7.78607E-13	1.06064E-12	-5.57919E-13	-3.25038E-7
Ω	5.78498E-17	-2.75265E-15	-7.78607E-13	5.12788E-12	-2.34591E-12	-5.26336E-12	9.82741E-8
ω	-7.37391E-16	6.40771E-15	1.06064E-12	-2.34591E-12	2.92841E-12	-7.18936E-13	-9.01561E-7
M	4.07328E-16	-5.33377E-15	-5.57919E-13	-5.26336E-12	-7.18936E-13	1.48879E-11	6.39482E-7
A₂	4.89797E-10	-2.45346E-9	-3.25038E-7	9.82741E-8	-9.01561E-7	6.39482E-7	5.91848E-1

Date of computation: 2025-11-13 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

19.80

19.79

Unit

Source

[8]

[1]

Quality

Value

Unit

Source

[8]

Amplitude

Value

0.5

0.35-0.41

Unit

mag

Source

[1]

[8]

Rotation Direction

Value

Unit

Source

[-]

Spinvector L

Value

Unit

Source

[1]

Spinvector B

Value

Unit

Source

[1]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[3]

[4]

[5]

Taxonomy (all)

Value

K;S,Sr;C

Unit

Source

[6]

[7]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

16.258

16.054

Unit

mag

Source

[9]

[10]

Slope Parameter (G)

Value

0.15**

0.12

Unit

mag

Source

[9]

[11]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.14

Unit

Source

[13]

Diameter

Value

2240

Unit

Source

[12]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.31

0.449

0.719

0.3342

Unit

R-I

U-B

V-R

B-V

g-r

Source

[14]

[15]

[14]

[3]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Visual S

Radar R

Unit

Source

[16]

[17]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Near-Earth Asteroid Lightcurve Analysis at the Center for Solar System Studies: 2019 July-September, 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) 2.) Kaasalainen, M. et al. (2004) Icarus 167, 178-196. (Photometry and models of eight near-Earth asteroids;1580, 1627,1980,2100,3199,3908,4957,5587)
[3]	EARN	1.) A. V. Sergeyev, B. Carry et al A&A, 658 (2022) A109
[4]	EARN	1.) Michaël Marsset et al 2022 AJ 163 165
[5]	EARN	1.) Shepard, M.K. et al. (2008) Icarus 193, 20-38. (Multi-wavelength observations of Asteroid 2100 Ra-Shalom)
[6]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[7]	EARN	1.) Shepard, M.K. et al. (2008) Icarus 193, 20-38. (Multi-wavelength observations of Asteroid 2100 Ra-Shalom) 2.) Tholen, D.J. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1139-1150. 3.) Harris, A.W. (DLR) et al. (1998) Icarus 135, 441-450. (Thermal Infrared Spectrophotometry of the Near-Earth Asteroids 2100 Ra-Shalom and 1991 EE) 4.) 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.) 5.) 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.)
[8]	EARN	1.) Harris, A.W. et al. (1992) Icarus 95, 115-147. (Asteroid lightcurve observations from 1981) 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.) Krugly, Yu.N. et al. (2002) Icarus 158, 294-304. (The Near-Earth Objects Follow-up Program. IV. CCD Photometry in 1996-1999). 4.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods" 5.) Ostro, S.J. et al. (1984) Icarus 60, 391-403. (Radar and photoelectric observations of asteroid 2100 Ra-Shalom) 6.) Harris, A.W. (DLR) (1998) Icarus 131, 291-301. (A Thermal Model for Near-Earth Asteroids) 7.) Harris, A.W. (DLR) et al. (1998) Icarus 135, 441-450. (Thermal Infrared Spectrophotometry of the Near-Earth Asteroids 2100 Ra-Shalom and 1991 EE) 8.) Delbo, M. et al. (2003) Icarus 166, 116-130. (Keck observations of near-Earth asteroids in the thermal infrared) 9.) Kaasalainen, M. et al. (2004) Icarus 167, 178-196. (Photometry and models of eight near-Earth asteroids;1580, 1627,1980,2100,3199,3908,4957,5587) 10.) Shepard, M.K. et al. (2008) Icarus 193, 20-38. (Multi-wavelength observations of Asteroid 2100 Ra-Shalom) 11.) Torppa, J. et al. (2008) Icarus 198, 91-107. (Asteroid shape and spin statistics from convex models) (1036,1580, 1627,1862,1980,2100,3908,5587,6053) 12.) Warner, B.D. (2017) MPB 44, 22-36. (NEAR-EARTH ASTEROID LIGHTCURVE ANALYSIS AT CS3-PALMER DIVIDE STATION: 2016 JULY-SEPTEMBER) (46 NEAs)
[9]	ESA Aegis	ESA orbit determination and impact monitoring system
[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) 3.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods"
[11]	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.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods"
[12]	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.) Shepard, M.K. et al. (2008) Icarus 193, 20-38. (Multi-wavelength observations of Asteroid 2100 Ra-Shalom) 3.) 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) 4.) Harris(DLR), A.W. et al. (2011) Astron. J. 141, 75. (ExploreNEOs. II. THE ACCURACY OF THE WARM SPITZER NEAR-EARTH OBJECT SURVEY) 5.) Mueller, M. et al. (2011) Astron. J. 141, 109. (ExploreNEOs. III. PHYSICAL CHARACTERIZATION OF 65 POTENTIAL SPACECRAFT TARGET ASTEROIDS) 6.) Delbo, M. et al. (2011) Icarus 212, 138-148. (The cool surfaces of binary near-Earth asteroids) (5381,153591, 164121) 7.) Masiero, J.R. et al. (2018) Astron. J. 154_168(10pp). (NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos) (170NEOs, 6110MBAs) 8.) 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.) 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.) Delbo, M. et al. (2003) Icarus 166, 116-130. (Keck observations of near-Earth asteroids in the thermal infrared) 3.) Harris, A.W. (DLR) et al. (1998) Icarus 135, 441-450. (Thermal Infrared Spectrophotometry of the Near-Earth Asteroids 2100 Ra-Shalom and 1991 EE) 4.) Veeder, G.J. et al. (1989) Astron. J. 97, 1211-1219. (Radiometry of near-earth asteroids) 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.) Mueller, M. et al. (2011) Astron. J. 141, 109. (ExploreNEOs. III. PHYSICAL CHARACTERIZATION OF 65 POTENTIAL SPACECRAFT TARGET ASTEROIDS) 7.) Masiero, J.R. et al. (2018) Astron. J. 154_168(10pp). (NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos) (170NEOs, 6110MBAs)
[14]	EARN	1.) Lin, C-H. et al. (2018) P&SS 152, 116-135. (Photometric survey and taxonomic identifications of 92 near-Earth asteroids)
[15]	EARN	1.) Tedesco, E.F. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1090-1138.
[16]	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.) Shepard, M.K. et al. (2008) Icarus 193, 20-38. (Multi-wavelength observations of Asteroid 2100 Ra-Shalom)
[17]	EARN	1.) Ostro, S.J. et al. (1984) Icarus 60, 391-403. (Radar and photoelectric observations of asteroid 2100 Ra-Shalom) 2.) Ostro, S.J. et al. (1991) Astron. J. 102, 1490-1502. (Asteroid radar astrometry) 3.) Shepard, M.K. et al. (2000) Icarus 147, 520-529. (Radar observations of Asteroid 2100 Ra-Shalom) 4.) Shepard, M.K. et al. (2008) Icarus 193, 20-38. (Multi-wavelength observations of Asteroid 2100 Ra-Shalom)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

18303

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.377428

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1975-10-03.1756

Unit

Source

[2]

Last Observation

Value

2025-11-12.242785

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

5036 (39)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

1981-08-25

Unit

Source

[3]

Last Observation

Value

2022-09-03

Unit

Source

[3]

Delay (Discarded)

Value

9 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

2 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

11 (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 2100 Ra-Shalom 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	1953-10-07 08:40	< 1 min	0.1506806	0.1506804	0.0000001
EARTH	1956-09-17 17:35	< 1 min	0.1835447	0.1835445	0.0000001
EARTH	1959-08-28 17:49	< 1 min	0.1857276	0.1857275	0.0000000
EARTH	1962-08-10 19:48	< 1 min	0.1765545	0.1765544	0.0000001
EARTH	1972-10-13 18:22	< 1 s	0.1744880	0.1744876	0.0000001
EARTH	1975-10-03 00:20	< 1 min	0.1595451	0.1595450	0.0000000
EARTH	1978-09-12 09:04	< 1 min	0.1884379	0.1884379	0.0000000
EARTH	1981-08-22 11:08	< 1 min	0.1800371	0.1800370	0.0000000
EARTH	1984-08-08 05:04	< 1 s	0.1897345	0.1897344	0.0000000
EARTH	1994-10-12 22:41	< 1 s	0.1549444	0.1549443	0.0000000
EARTH	1997-09-26 23:28	< 1 s	0.1704765	0.1704764	0.0000000
EARTH	2000-09-06 01:00	< 1 s	0.1895574	0.1895574	0.0000000
EARTH	2003-08-17 14:29	< 1 s	0.1744538	0.1744538	0.0000000
EARTH	2016-10-09 14:09	< 1 s	0.1499070	0.1499070	0.0000000
EARTH	2019-09-21 20:02	< 1 s	0.1797233	0.1797233	0.0000000
EARTH	2022-08-31 17:26	< 1 s	0.1873287	0.1873287	0.0000000
EARTH	2025-08-12 15:41	< 1 s	0.1729038	0.1729038	0.0000000
EARTH	2035-10-15 00:13	< 1 s	0.1906057	0.1906055	0.0000001
EARTH	2038-10-05 16:24	< 1 min	0.1553202	0.1553202	0.0000000
EARTH	2041-09-15 12:43	< 1 min	0.1863573	0.1863573	0.0000000
EARTH	2044-08-25 11:02	< 1 min	0.1823039	0.1823039	0.0000000
EARTH	2047-08-10 06:12	< 1 s	0.1799297	0.1799295	0.0000001
EARTH	2057-10-13 22:06	< 1 s	0.1645554	0.1645549	0.0000002
EARTH	2060-09-29 23:15	< 1 min	0.1653375	0.1653373	0.0000001
EARTH	2063-09-10 05:28	< 1 min	0.1892922	0.1892922	0.0000000
EARTH	2066-08-20 09:19	< 1 min	0.1760154	0.1760152	0.0000001
EARTH	2069-08-08 09:33	< 1 s	0.1986666	0.1986656	0.0000003
EARTH	2079-10-12 08:43	< 1 min	0.1521730	0.1521727	0.0000001
EARTH	2082-09-24 19:29	< 1 min	0.1756281	0.1756276	0.0000002
EARTH	2085-09-03 21:30	< 1 min	0.1885206	0.1885205	0.0000000
EARTH	2088-08-15 00:04	< 1 min	0.1717117	0.1717116	0.0000000
EARTH	2101-10-09 07:22	< 1 min	0.1526129	0.1526124	0.0000001
EARTH	2104-09-19 15:30	< 1 min	0.1834490	0.1834483	0.0000002
EARTH	2107-08-30 14:24	< 1 min	0.1844863	0.1844858	0.0000002
EARTH	2110-08-12 17:27	< 1 min	0.1735355	0.1735347	0.0000003
EARTH	2120-10-15 12:04	< 1 min	0.1782067	0.1782029	0.0000013
EARTH	2123-10-04 22:00	< 1 min	0.1607080	0.1607066	0.0000005

Download as:

Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
227.31165090	276.27223846	0.14985356	MINIMUM
138.70299039	220.52192903	0.17207148	MINIMUM
176.50948046	244.33176943	0.18885926	SADDLE
5.23967440	71.73516010	0.52541367	SADDLE
4.27121342	250.24382763	1.47611314	SADDLE
181.70779034	67.47480527	2.18897108	MAXIMUM

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MOID Plots

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