Asteroids

1627 Ivar help

Last update: 2026-06-10 13:00 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Amor

Perihelion (q)

1.123

Aphelion (Q)

2.603

Eccentricity (e)

0.397

Inclination (i)

8.5

deg

Orbit period (P)

928.9

Earth MOID

0.11013

U parameter

0.0

Next Earth close approach

Date

2046-08-06

Nominal distance (from Earth center)

0.17748

26550151

Maximum Brightness

10.9

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

13.2

mag

Diameter

9010

Taxonomic type

Rotation period (T)

4.796

Discovery Information

Discovery Date

1929-09-25

Observatory

Johannesburg

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

1.863110

1-sigma variation

1.687E-10

Unit

Eccentricity (e)

Value

0.397335

1-sigma variation

1.211E-8

Unit

Inclination (i)

Value

8.4563

1-sigma variation

1.854E-6

Unit

Long. of Ascending Node (Ω)

Value

133.0740

1-sigma variation

1.130E-5

Unit

Arg. of Perihelion (ω)

Value

167.8309

1-sigma variation

1.120E-5

Unit

Mean Anomaly (M)

Value

28.98027

1-sigma variation

9.248E-7

Unit

Perihelion distance

Value

1.122832

1-sigma variation

Unit

Aphelion distance

Value

2.603389

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

1.579929

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.115309

1-sigma variation

Unit

MOID

Value

0.110130

1-sigma variation

Unit

Orbit Period

Value

928.8729

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	2.84509E-20	9.73859E-19	1.05584E-17	-5.03670E-16	5.49052E-16	-2.75402E-17
e	9.73859E-19	1.46730E-16	2.59812E-15	1.60485E-14	-1.02150E-14	1.90579E-16
i	1.05584E-17	2.59812E-15	3.43862E-12	-1.68075E-12	1.79204E-12	-1.04208E-13
Ω	-5.03670E-16	1.60485E-14	-1.68075E-12	1.27715E-10	-1.24089E-10	-1.83897E-12
ω	5.49052E-16	-1.02150E-14	1.79204E-12	-1.24089E-10	1.25449E-10	-9.44194E-14
M	-2.75402E-17	1.90579E-16	-1.04208E-13	-1.83897E-12	-9.44194E-14	8.55212E-13

Date of computation: 2026-06-10 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

4.796

4.795

Unit

Source

[1]

[9]

Quality

Value

Unit

Source

[9]

Amplitude

Value

0.25-1.15

1.55

Unit

mag

Source

[9]

[1]

Rotation Direction

Value

PRO

Unit

Source

[2]

[-]

Spinvector L

Value

Unit

Source

[1]

Spinvector B

Value

-14

Unit

Source

[1]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[3]

[4]

[5]

[6]

Taxonomy (all)

Value

Unit

Source

[7]

[8]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

12.61

13.226

Unit

mag

Source

[10]

[11]

Slope Parameter (G)

Value

0.6**

Unit

Source

[11]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.127

0.174

Unit

Source

[12]

[14]

Diameter

Value

9010

Unit

Source

[12]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.1356
2.1514
2.5997
0.5839
2.2092
1.5209
0.6883
0.325
-0.104
0.83
0.4483
1.9692
0.432
2.8397
2.1048
0.6305
0.24
0.46
2.7353

Unit

r-z

u-g

u-r

g-z

v-i

v-g

g-i

R-I

i-z

B-V

g-r

v-r

V-R

u-i

v-z

u-v

r-i

U-B

u-z

Source

[5]

[15]

[5]

[15]

[5]

[15]

[5]

[16]

[5]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Visual S

Radar R

Unit

Source

[17]

[18]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Lowell Observatory Near-Earth Asteroid Photometric Survey (NEAPS): Paper 3. Skiff, Brian A et al.
[2]	EARN	1.) Crowell, J.L. et al. (2016) Icarus in press. (Radar and Lightcurve Shape Model of Near-Earth Asteroid (1627) Ivar) 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.) Velichko, F.P. & D.F. Lupishko (1989) Kinematika i Fizika Nebesnykh Tel 5, 90-94. (Photometric astrometry for asteroids approaching the earth - Pole coordinates of 1627 Ivar)
[3]	EARN	1.) Thomas, C.A. et al. (2014) Icarus 228, 217-246. (Physical characterization of Warm Spitzer-observed near-Earth objects)
[4]	EARN	1.) Michaël Marsset et al 2022 AJ 163 165
[5]	EARN	1.) A. V. Sergeyev, B. Carry et al A&A, 658 (2022) A109
[6]	EARN	1.) Alexey V. Sergeyev and Benoit Carry A&A, 652 (2021) A59
[7]	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.) Davies, J.K. et al. (2007) Icarus 186,111-125. (Near-infrared spectra of 12 near-Earth objects) (1627,4179, 5381,5587,6489,11405,14402,25143,25330,52760,66391,101955)
[8]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[9]	EARN	1.) Crowell, J.L. et al. (2016) Icarus in press. (Radar and Lightcurve Shape Model of Near-Earth Asteroid (1627) Ivar) 2.) Hahn, G. et al. (1989) Icarus 78, 363-381. (Physical studies of Apollo-Amor asteroids - UBVRI photometry of 1036 Ganymed and 1627 Ivar) 3.) Lupishko, D.F. et al. (1986) Kin. Fiz. Neb. Tel. 2(5), 39-43. (1627..) 4.) Chernova, G.P. et al. (1995) Astron. J. 110, 1875-1878. (Photometry of Amor Asteroids 1036 Ganymede and 1627 Ivar) 5.) Harris, A.W. & J.W. Young (1985) B.A.A.S. 17, 726. (Photometric Results for Earth Approaching Asteroids.) (1627,1036,1862,1982RA,1982XB,1983RD,1984KD) 6.) Hoffmann, M. & E.H. Geyer (1990) Acta Astronomica 40, 389-396. (Photometric observations of three near-earth asteroids) (1627) (3908) (1685) 7.) Velichko, F.P. et al. (1990) Astron.Tsirk 1546, 39-40. (Such unlike asteroids 1627 ivar and 1951 Lick) 8.) Pravec, P. et al. (1996) Icarus 124, 471-482. (Lightcurves of 7 Near-Earth Asteroids)(1627,4957,6569,1993UC,1994AH2, 1994CB,1994LX) 9.) Harris, A.W. (DLR) (1998) Icarus 131, 291-301. (A Thermal Model for Near-Earth Asteroids) 10.) Kiss, L.L. et al. (1999) Astron. Astrophys. Suppl. 140, 21-28. (CCD photometry and new models of 5 minor planets) (..1627..) 11.) Szabo, Gy. & L.L. Kiss (2001) Publ. Astron. Dept Eotvos Univ. Nr. 11, 119-124. (CCD photometric investigations of small bodies in the solar system; 1627,1865) 12.) Delbo, M. et al. (2003) Icarus 166, 116-130. (Keck observations of near-Earth asteroids in the thermal infrared) 13.) 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) 14.) 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) 15.) Skiff, B.A. et al. (2012) MPB 39, 111-130. (LOWELL OBSERVATORY NEAR-EARTH ASTEROID PHOTOMETRIC SURVEY (NEAPS) - 2008 MAY THROUGH 2008 DECEMBER) (46 NEAs) 16.) Warner, B.D. (2014) MPB 41,41-47. (NEAR-EARTH ASTEROID LIGHTCURVE ANALYSIS AT CS3-PALMER DIVIDE STATION: 2013 JUNE-SEPTEMBER) (1627,9950,11405,24445,152664,168378,329437, 350988,361071,368664,2006EE1,2013OM9,2013QJ10) 17.) Warner, B.D. (2015) MPB 42, 172-183. (NEAR-EARTH ASTEROID LIGHTCURVE ANALYSIS AT CS3-PALMER DIVIDE STATION: 2015 JANUARY - MARCH)(35NEAs) 18.) 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) 19.) Warner, B.D. (2018) MPB 45, 366-379. (Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2018 April-June)(39 NEAs)
[10]	EARN	1.) Rikhteghar, A. & F.P. Velichko (2010) LPSC 41, 2528. (PHASE FUNCTION OF BRIGHTNESS OF NEA 1627 IVAR) 2.) Hahn, G. et al. (1989) Icarus 78, 363-381. (Physical studies of Apollo-Amor asteroids - UBVRI photometry of 1036 Ganymed and 1627 Ivar)
[11]	ESA Aegis	ESA orbit determination and impact monitoring system
[12]	EARN	1.) Joseph R. Masiero et al 2020 Planet. Sci. J. 1 5
[13]	EARN	1.) Crowell, J.L. et al. (2016) Icarus in press. (Radar and Lightcurve Shape Model of Near-Earth Asteroid (1627) Ivar) 2.) Mainzer, A. et al. (2014) Astrophys. J. 792, 30. (Initial Performance of the NEOWISE Reactivation Mission) (prel.diameters & albedos for 61 NEOs) 3.) Mainzer, A. et al. (2011) ApJ 743, 156. (NEOWISE Observations of Near-Earth Objects: Preliminary Results) (albedo and diameters of 428 NEOs) 4.) Mueller, M. et al. (2011) Astron. J. 141, 109. (ExploreNEOs. III. PHYSICAL CHARACTERIZATION OF 65 POTENTIAL SPACECRAFT TARGET ASTEROIDS) 5.) Delbo, M. et al. (2003) Icarus 166, 116-130. (Keck observations of near-Earth asteroids in the thermal infrared) 6.) Ostro, S.J. et al. (1990) Astron. J. 99, 2012-2018. (Radar images of asteroid 1627 Ivar) 7.) Veeder, G.J. et al. (1989) Astron. J. 97, 1211-1219. (Radiometry of near-earth asteroids) 8.) Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; et al. (2011) Astrophys. J. 741, A90. See also Grav 2012b and Masiero 2012.
[14]	EARN	1.) Mainzer, A. et al. (2014) Astrophys. J. 792, 30. (Initial Performance of the NEOWISE Reactivation Mission) (prel.diameters & albedos for 61 NEOs) 2.) Mainzer, A. et al. (2011) ApJ 743, 156. (NEOWISE Observations of Near-Earth Objects: Preliminary Results) (albedo and diameters of 428 NEOs) 3.) Masiero, J.R. et al. (2012) Astrophys. J. 749, 104. (A REVISED ASTEROID POLARIZATION-ALBEDO RELATIONSHIP USING WISE/NEOWISE DATA) (887,1036,1627,1685) 4.) 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) 5.) Mueller, M. et al. (2011) Astron. J. 141, 109. (ExploreNEOs. III. PHYSICAL CHARACTERIZATION OF 65 POTENTIAL SPACECRAFT TARGET ASTEROIDS) 6.) Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; et al. (2011) Astrophys. J. 741, A90. See also Grav 2012b and Masiero 2012.
[15]	EARN	1.) Lin, C-H. et al. (2018) P&SS 152, 116-135. (Photometric survey and taxonomic identifications of 92 near-Earth asteroids)
[16]	EARN	1.) Hahn, G. et al. (1989) Icarus 78, 363-381. (Physical studies of Apollo-Amor asteroids - UBVRI photometry of 1036 Ganymed and 1627 Ivar)
[17]	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.) deLeon, J. et al. (2006) Advanc. Space Res. 37, 178-183. (Spectral analysis and mineralogical characterization of 11 olivine-pyroxene rich NEAs) (1627,1864,3122,25143,65803, 1999BY9,1999TF211,2000VJ61,2000XH44,2003HM16,2003YG118) 4.) Davies, J.K. et al. (2007) Icarus 186,111-125. (Near-infrared spectra of 12 near-Earth objects) (1627,4179, 5381,5587,6489,11405,14402,25143,25330,52760,66391,101955) 5.) 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) 6.) deLeon, J. et al. (2010) Astron. Astrophys 517, A23. (Observations, compositional, and physical characterization of near-Earth and Mars-crosser asteroids from a spectroscopic survey) 7.) Sanchez, J.A. et al. (2012) Icarus 220, 36-50. (Phase reddening on near-Earth asteroids: Implications for mineralogical analysis, space weathering and taxonomic classification) (1036,1620,1627,1862,1980,4179,4954,6239, 11398,25143,35107,66146) 8.) Thomas, C.A. et al. (2014) Icarus 228, 217-246. (Physical characterization of Warm Spitzer-observed near-Earth objects)
[18]	EARN	1.) Moskovitz, N.A. et al. (2017) Icarus 284, 97-105. (Near-infrared thermal emission from near-Earth asteroids: Aspect-dependent variability)(285263,175706) 2.) Ostro, S.J. et al. (1990) Astron. J. 99, 2012-2018. (Radar images of asteroid 1627 Ivar) 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

34961

Unit

Source

[1]

Unobserved

Value

384

Unit

Source

[1]

Normalized RMS of residuals

Value

0.334334

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1929-09-25.96

Unit

Source

[2]

Last Observation

Value

2025-06-15.269578

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

14376 (59)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

1985-07-08

Unit

Source

[3]

Last Observation

Value

2013-07-04

Unit

Source

[3]

Delay (Discarded)

Value

3 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

1 (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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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 1627 Ivar 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	1957-07-21 08:58	< 1 s	0.1501798	0.1501797	0.0000000
EARTH	2046-08-06 06:41	< 1 s	0.1774768	0.1774767	0.0000000
EARTH	2074-08-03 16:47	< 1 s	0.1407384	0.1407384	0.0000000
EARTH	2102-08-06 04:17	< 1 min	0.1569511	0.1569509	0.0000001

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
2.88398721	201.28446765	0.11012962	MINIMUM
179.40189197	16.13693298	1.61999910	SADDLE
359.18303096	15.62006135	2.10670656	SADDLE
179.92443411	196.47132669	3.61918194	MAXIMUM

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MOID Plots

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