Asteroids

887 Alinda help

Last update: 2025-09-25 13:26 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Amor

Perihelion (q)

1.061

Aphelion (Q)

3.886

Eccentricity (e)

0.571

Inclination (i)

9.4

deg

Orbit period (P)

1421.0

Earth MOID

0.07968

U parameter

0.0

Next Earth close approach

Date

2087-01-25

Nominal distance (from Earth center)

0.16633

24881955

Maximum Brightness

12.7

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

13.4

mag

Diameter

4787

Taxonomic type

Rotation period (T)

73.97

Discovery Information

Discovery Date

1918-01-03

Observatory

Heidelberg-Konigstuhl

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

2.473629

1-sigma variation

1.551E-9

Unit

Eccentricity (e)

Value

0.571170

1-sigma variation

1.268E-9

Unit

Inclination (i)

Value

9.4001

1-sigma variation

1.070E-6

Unit

Long. of Ascending Node (Ω)

Value

110.4059

1-sigma variation

4.371E-6

Unit

Arg. of Perihelion (ω)

Value

350.5345

1-sigma variation

5.367E-6

Unit

Mean Anomaly (M)

Value

81.54059

1-sigma variation

4.859E-7

Unit

Perihelion distance

Value

1.060766

1-sigma variation

Unit

Aphelion distance

Value

3.886491

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.082271

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

2.799573

1-sigma variation

Unit

MOID

Value

0.079677

1-sigma variation

Unit

Orbit Period

Value

1421.0201

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	2.40444E-18	-1.40755E-19	-1.44321E-16	-3.01522E-15	4.71284E-15	-5.50721E-16
e	-1.40755E-19	1.60773E-18	1.19867E-16	-1.01976E-15	-4.08082E-16	1.92398E-16
i	-1.44321E-16	1.19867E-16	1.14387E-12	4.63964E-13	-5.69102E-13	6.16983E-14
Ω	-3.01522E-15	-1.01976E-15	4.63964E-13	1.91033E-11	-2.21890E-11	1.38008E-12
ω	4.71284E-15	-4.08082E-16	-5.69102E-13	-2.21890E-11	2.88009E-11	-2.21743E-12
M	-5.50721E-16	1.92398E-16	6.16983E-14	1.38008E-12	-2.21743E-12	2.36057E-13

Date of computation: 2025-09-25 13:26 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

73.97

Unit

Source

[4]

Quality

Value

Unit

Source

[4]

Amplitude

Value

0.35

Unit

mag

Source

[4]

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]

Taxonomy (all)

Value

Unit

Source

[3]

[2]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

13.83

13.411

Unit

mag

Source

[5]

[6]

Slope Parameter (G)

Value

-0.12**

-0.084

Unit

mag

Source

[6]

[7]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.336

Unit

Source

[9]

Diameter

Value

4787

Unit

Source

[8]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

0.5

0.3718

0.6672

0.86

0.298

Unit

U-B

g-r

g-i

B-V

r-i

Source

[10]

[1]

[10]

[1]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Unit

Source

[-]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) A. V. Sergeyev, B. Carry et al A&A, 658 (2022) A109
[2]	EARN	1.) Tholen, D.J. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1139-1150.
[3]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[4]	EARN	1.) Dunlap, J.L. & R.C. Taylor (1979) Astron. J. 84, 269-273. (Minor planets and related objects. XXVII - Lightcurves of 887 Alinda) 2.) Tungalag, N. et al. (2002) Kin. Fiz. Neb. Tel. 18, 508-516. (Rotation parameters and shapes of 15 asteroids; ..887..)
[5]	EARN	1.) Tedesco, E.F. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1090-1138. 2.) Dunlap, J.L. & R.C. Taylor (1979) Astron. J. 84, 269-273. (Minor planets and related objects. XXVII - Lightcurves of 887 Alinda) 3.) Tedesco, E.F. (1975) MPB 2, 25-27. (Determination of the absolute magnitude and phase coefficient of minor planet (887) Alinda)
[6]	ESA Aegis	ESA orbit determination and impact monitoring system
[7]	EARN	1.) Tedesco, E.F. (1989) in "Asteroids II" (Eds. R.P.Binzel et al.), Univ.Ariz.Press, Tucson, USA, pp. 1090-1138.
[8]	EARN	1.) Mainzer, A. et al. (2011) ApJ 743, 156. (NEOWISE Observations of Near-Earth Objects: Preliminary Results) (albedo and diameters of 428 NEOs) 2.) Veeder, G.J. et al. (1989) Astron. J. 97, 1211-1219. (Radiometry of near-earth asteroids) 3.) Morrison, D. (1974) Astrophys. J. 194, 203-212. (Radiometric diameters and albedos of 40 asteroids)
[9]	EARN	1.) Mainzer, A. et al. (2011) ApJ 743, 156. (NEOWISE Observations of Near-Earth Objects: Preliminary Results) (albedo and diameters of 428 NEOs) 2.) Masiero, J.R. et al. (2012) Astrophys. J. 749, 104. (A REVISED ASTEROID POLARIZATION-ALBEDO RELATIONSHIP USING WISE/NEOWISE DATA) (887,1036,1627,1685) 3.) Veeder, G.J. et al. (1989) Astron. J. 97, 1211-1219. (Radiometry of near-earth asteroids) 4.) Morrison, D. (1974) Astrophys. J. 194, 203-212. (Radiometric diameters and albedos of 40 asteroids)
[10]	EARN	1.) Dunlap, J.L. & R.C. Taylor (1979) Astron. J. 84, 269-273. (Minor planets and related objects. XXVII - Lightcurves of 887 Alinda)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

39317

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.367864

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1918-01-03.84861

Unit

Source

[2]

Last Observation

Value

2025-08-27.004183

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

6024 (33)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2024-12-08

Unit

Source

[3]

Last Observation

Value

2025-01-26

Unit

Source

[3]

Delay (Discarded)

Value

16 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

16 (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 887 Alinda 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	1974-01-04 05:00	< 1 min	0.1367787	0.1367787	0.0000000
EARTH	2025-01-08 13:39	< 1 s	0.0821977	0.0821977	0.0000000
EARTH	2087-01-25 21:49	< 1 min	0.1663256	0.1663247	0.0000003

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
2.40907992	4.24084924	0.07967704	MINIMUM
359.80503993	179.40144104	2.07873967	SADDLE
179.87090569	179.69191400	2.86882295	SADDLE
180.07030055	359.79524495	4.86975487	MAXIMUM

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MOID Plots

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