Asteroids

1998KY26 help

Last update: 2025-09-10 00:30 UTC

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.983

Aphelion (Q)

1.475

Eccentricity (e)

0.200

Inclination (i)

1.5

deg

Orbit period (P)

497.6

Earth MOID

0.00297

U parameter

1.0

A₂

-273.1

10^-15au/days²

Next Earth close approach

Date

2039-05-24

Nominal distance (from Earth center)

0.10816

16181019

Maximum Brightness

23.4

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

25.6

mag

Diameter

<=40.0

Taxonomic type

Rotation period (T)

0.1784

Discovery Information

Discovery Date

1998-05-28

Observatory

Steward Observatory, Kitt Peak-Spacewatch

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

1.228869

1-sigma variation

2.799E-8

Unit

Eccentricity (e)

Value

0.200110

1-sigma variation

6.508E-8

Unit

Inclination (i)

Value

1.4912

1-sigma variation

2.785E-6

Unit

Long. of Ascending Node (Ω)

Value

84.1821

1-sigma variation

1.792E-5

Unit

Arg. of Perihelion (ω)

Value

210.0038

1-sigma variation

3.539E-5

Unit

Mean Anomaly (M)

Value

0.98343

1-sigma variation

0.00001

Unit

Perihelion distance

Value

0.982960

1-sigma variation

Unit

Aphelion distance

Value

1.474778

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.442277

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.011748

1-sigma variation

Unit

MOID

Value

0.002966

1-sigma variation

Unit

Orbit Period

Value

497.5733

1-sigma variation

Unit

U parameter

Value

1.0

1-sigma variation

Unit

A₂

Value

-273.07842

1-sigma variation

36.68480

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	7.83650E-16	-1.73994E-15	-1.78199E-14	-4.85252E-14	-7.93776E-13	1.44914E-13	1.01725E-6
e	-1.73994E-15	4.23556E-15	4.43108E-14	1.12271E-13	1.95055E-12	-4.29008E-13	-2.31208E-6
i	-1.78199E-14	4.43108E-14	7.75816E-12	-4.47268E-11	6.78894E-11	-5.85916E-12	-2.39991E-5
Ω	-4.85252E-14	1.12271E-13	-4.47268E-11	3.21009E-10	-2.81148E-10	8.67320E-13	-6.28634E-5
ω	-7.93776E-13	1.95055E-12	6.78894E-11	-2.81148E-10	1.25259E-9	-2.19129E-10	-1.04965E-3
M	1.44914E-13	-4.29008E-13	-5.85916E-12	8.67320E-13	-2.19129E-10	6.59733E-11	1.92333E-4
A₂	1.01725E-6	-2.31208E-6	-2.39991E-5	-6.28634E-5	-1.04965E-3	1.92333E-4	1.34578E3

Date of computation: 2025-09-10 00:30 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

0.1784

Unit

Source

[1]

Quality

Value

Unit

Source

[1]

Amplitude

Value

0.3

Unit

mag

Source

[1]

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

[-]

Taxonomy (all)

Value

Unit

Source

[-]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

25.567

24.95

Unit

mag

Source

[2]

[3]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[2]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

dark

Unit

Source

[5]

Diameter

Value

<=40.0

Unit

Source

[4]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Radar R

Unit

Source

[6]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Pravec, P. & L Sarounova (1998) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/06900/06941.html"> 6941. (1998 KY26 - rotation period) 2.) Ostro, S. J. et al (1999) Science 285, 557-559. (Radar and Optical Observations of Asteroid 1998 KY26) 3.) Whiteley, R.J. et al. (2002) Proceedings of ACM2002, ESA-SP500, pp. 473-480. (Monolithic fast-rotating asteroids) (H-values and rotation properties of 36 NEAs) 4.) Hicks, M.D. et al. (1998) B.A.A.S. 30, 1029. (Close encounters: Observations of the Earth-crossing asteroids 1998 KY26 and 1998 ML14) 5.) Ostro, S.J. et al. (1998) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/06900/06935.html"> 6935. (1998 KY26 - radar period size) 6.) Hicks, M.D. et al. (1998) B.A.A.S. 30, 1029. (Close Encounters: Observations of the Earth-crossing Asteroids 1998 KY26 and 1998 ML14)
[2]	ESA Aegis	ESA orbit determination and impact monitoring system
[3]	EARN	1.) Hicks, M.D. & D.L. Rabinowitz (1998) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/06900/06945.html"> 6945. (1998 KY26 - BVRI photometry period ampl) 2.) Ostro, S. J. et al (1999) Science 285, 557-559. (Radar and Optical Observations of Asteroid 1998 KY26)
[4]	EARN	1.) Ostro, S.J. et al. (1998) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/06900/06935.html"> 6935. (1998 KY26 - radar period size)
[5]	EARN	1.) Binzel, R.P. et al. (2002) in "Asteroids III" (Eds. W.F.Bottke et al.), Univ.Ariz.Press, Tucson, USA, pp. 255-271. (Physical Properties of NEOs) 2.) Hicks, M. et al. (1998) B.A.A.S. 30,1029. (Close Encounters: Observations of the Earth-crossing Asteroids 1998 KY26 and 1998 ML14)
[6]	EARN	1.) Ostro, S.J. et al. (1998) I.A.U. Circ. HREF="http://www.cbat.eps.harvard.edu/iauc/06900/06935.html"> 6935. (1998 KY26 - radar period size) 2.) Ostro, S.J. et al. (1998) B.A.A.S 30, 1036. (Near-Earth-Asteroid Radar at Goldstone, Aug 1996 - Jun 1998) [7822(1991CS),4197(1982TA),4179Toutatis,7341(1991VK), 7482(1994PC1),1997BR,1998BY7,6037(1988EG),1998KY26] 3.) Ostro S.J. et al., (1999) Science 285, 557-559. (Radar and Optical Observations of Asteroid 1998 KY26.) 4.) Ostro, S. J. et al (1999) Science 285, 557-559. (Radar and Optical Observations of Asteroid 1998 KY26)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

9503

Unit

Source

[1]

Unobserved

Value

488

Unit

Source

[1]

Normalized RMS of residuals

Value

0.644378

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1998-05-28.22782

Unit

Source

[2]

Last Observation

Value

2024-06-03.366387

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

257 (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

1998-06-06

Unit

Source

[3]

Last Observation

Value

1998-06-08

Unit

Source

[3]

Delay (Discarded)

Value

2 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

2 (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

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 1998KY26 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	1959-06-07 10:10	1.1	0.0082416	0.0082353	0.0000021
EARTH	1984-08-19 14:22	< 1 min	0.0237368	0.0237360	0.0000003
EARTH	1991-07-08 23:52	1.2	0.0297620	0.0297616	0.0000001
EARTH	1998-06-08 05:45	< 1 s	0.0053888	0.0053888	0.0000000
EARTH	2013-09-06 04:04	< 1 min	0.1173185	0.1173147	0.0000013
EARTH	2024-06-01 16:03	< 1 s	0.0306777	0.0306776	0.0000000
EARTH	2039-05-24 10:02	< 1 min	0.1081634	0.1081513	0.0000040
EARTH	2058-09-05 02:16	< 1 min	0.0872063	0.0871913	0.0000050
EARTH	2073-08-30 20:15	< 1 min	0.0484167	0.0484127	0.0000013
EARTH	2099-06-04 03:00	< 1 min	0.0276847	0.0276742	0.0000035
EARTH	2118-08-27 06:03	22.1	0.0272099	0.0271327	0.0000259

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
330.76185252	156.14622168	0.00249362	MINIMUM
26.39095121	224.65024736	0.02346867	MINIMUM
1.50892331	194.02801662	0.03553131	SADDLE
179.55734656	11.46059963	0.49100482	SADDLE
359.15779319	11.09498429	1.96692074	SADDLE
179.34862843	191.28810889	2.49064862	MAXIMUM

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MOID Plots

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