Asteroids

4769 Castalia help

Last update: 2026-07-30 09:40 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.549

Aphelion (Q)

1.577

Eccentricity (e)

0.483

Inclination (i)

8.9

deg

Orbit period (P)

400.4

Earth MOID

0.02041

U parameter

0.0

A₂

-8.9

10^-15au/days²

Next Earth close approach

Date

2027-04-04

Nominal distance (from Earth center)

0.12883

19272097

Maximum Brightness

16.6

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

17.5

mag

Diameter

1300

Taxonomic type

Rotation period (T)

4.095

Discovery Information

Discovery Date

1989-08-09

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

61200.0000

1-sigma variation

Unit

MJD

Semimajor Axis

Value

1.063088

1-sigma variation

1.064E-9

Unit

Eccentricity (e)

Value

0.483176

1-sigma variation

3.135E-8

Unit

Inclination (i)

Value

8.8852

1-sigma variation

4.179E-6

Unit

Long. of Ascending Node (Ω)

Value

325.4991

1-sigma variation

9.905E-6

Unit

Arg. of Perihelion (ω)

Value

121.4523

1-sigma variation

9.981E-6

Unit

Mean Anomaly (M)

Value

143.61257

1-sigma variation

4.196E-6

Unit

Perihelion distance

Value

0.549430

1-sigma variation

Unit

Aphelion distance

Value

1.576747

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.077000

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.336675

1-sigma variation

Unit

MOID

Value

0.020407

1-sigma variation

Unit

Orbit Period

Value

400.3617

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

A₂

Value

-8.88596

1-sigma variation

0.86155

Unit

10^-15au/days²

Covariance Matrix

	a	e	i	Ω	ω	M	A₂
a	1.13138E-18	1.42300E-17	1.27655E-15	-3.97382E-15	4.94706E-15	-3.20740E-15	8.88813E-10
e	1.42300E-17	9.82997E-16	-1.92425E-14	3.39480E-14	2.97556E-14	1.75499E-14	5.59397E-9
i	1.27655E-15	-1.92425E-14	1.74607E-11	2.30707E-12	-3.15337E-12	-2.18387E-12	1.13304E-6
Ω	-3.97382E-15	3.39480E-14	2.30707E-12	9.81127E-11	-9.66481E-11	7.30526E-12	-4.07497E-6
ω	4.94706E-15	2.97556E-14	-3.15337E-12	-9.66481E-11	9.96265E-11	-6.57613E-12	4.51254E-6
M	-3.20740E-15	1.75499E-14	-2.18387E-12	7.30526E-12	-6.57613E-12	1.76080E-11	-2.94628E-6
A₂	8.88813E-10	5.59397E-9	1.13304E-6	-4.07497E-6	4.51254E-6	-2.94628E-6	7.42263E-1

Date of computation: 2026-07-30 09:40 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

4.095

Unit

Source

[3]

Quality

Value

Unit

Source

[3]

Amplitude

Value

0.64-1.0

Unit

mag

Source

[3]

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]

Taxonomy (all)

Value

Unit

Source

[2]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

17.513

16.9

Unit

mag

Source

[4]

[5]

Slope Parameter (G)

Value

0.15**

Unit

Source

[4]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.092

Unit

Source

[6]

Diameter

Value

1300

Unit

Source

[6]

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

[7]

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Sources

No.	Name	Additional
[1]	EARN	1.) Michaël Marsset et al 2022 AJ 163 165
[2]	EARN	Earth Asteroids Research Node: https://earn.dlr.de
[3]	EARN	1.) Hudson, R.S. et al. (1997) Icarus 130, 165-176. (Constraints on Spin State and Hapke Parameters of Asteroid 4769 Castalia Using Lightcurves and a Radar-Derived Shape Model) 2.) Ostro, S.J. et al. (1990) Science 248, 1523-1528. (Radar images of asteroid 1989 PB) 3.) Hudson R.S. & S.J. Ostro (1994) Science 263, 940-943. (Shape of Asteroid 4769 Castalia (1989 PB) from Inversion of Radar Images) 4.) Erikson, A. et al. (2000) Icarus 147, 487-497. (The Near-Earth Objects Follow-Up Program III: 32 Lightcurves for 12 Objects from 1992 to 1995) (433,1917,2368,3753,4769, 4953,6491, 1995 EK1, 1995 FJ; 5738,7467,1995 LH)
[4]	ESA Aegis	ESA orbit determination and impact monitoring system
[5]	EARN	1.) Hudson, R.S. et al. (1997) Icarus 130, 165-176. (Constraints on Spin State and Hapke Parameters of Asteroid 4769 Castalia Using Lightcurves and a Radar-Derived Shape Model)
[6]	EARN	1.) Masiero, J.R. et al. (2018) Astron. J. 154_168(10pp). (NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos) (170NEOs, 6110MBAs) 2.) 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)
[7]	EARN	1.) Hudson, R.S. & S.J. Ostro (1994) Science 263, 940-943. (Shape of Asteroid 4769 Castalia (1989 PB) from Inversion of Radar Images) 2.) Hudson, R.S. et al. (1997) Icarus 130, 165-176. (Constraints on Spin State and Hapke Parameters of Asteroid 4769 Castalia Using Lightcurves and a Radar-Derived Shape Model) 3.) Ostro, S.J. et al. (1990) Science 248, 1523-1528. (Radar images of asteroid 1989 PB) 4.) Hudson R.S. & S.J. Ostro (1994) Science 263, 940-943. (Shape of Asteroid 4769 Castalia (1989 PB) from Inversion of Radar Images) 5.) 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

13488

Unit

Source

[1]

Unobserved

Value

Unit

Source

[1]

Normalized RMS of residuals

Value

0.483112

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

1989-08-01.44844

Unit

Source

[2]

Last Observation

Value

2026-07-06.327476

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

746 (3)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

1989-08-19

Unit

Source

[3]

Last Observation

Value

2012-09-14

Unit

Source

[3]

Delay (Discarded)

Value

8 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

6 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

14 (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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Computation parameters

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Final Date: *

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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 4769 Castalia 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	1955-08-22 05:46	< 1 min	0.1057961	0.1057946	0.0000005
EARTH	1959-04-05 03:04	< 1 min	0.1217740	0.1217739	0.0000000
EARTH	1978-08-29 08:09	< 1 s	0.1440358	0.1440351	0.0000002
EARTH	1989-08-25 04:23	< 1 s	0.0269379	0.0269378	0.0000000
EARTH	1993-04-08 06:58	< 1 s	0.1319420	0.1319418	0.0000001
EARTH	2012-08-28 17:06	< 1 s	0.1135065	0.1135064	0.0000000
EARTH	2023-08-22 09:20	< 1 s	0.1100263	0.1100261	0.0000001
EARTH	2027-04-04 03:41	< 1 s	0.1288260	0.1288258	0.0000001
EARTH	2046-08-26 19:46	< 1 s	0.0250771	0.0250766	0.0000002
EARTH	2050-04-11 02:13	< 1 min	0.1557884	0.1557875	0.0000003
EARTH	2057-08-19 19:48	< 1 min	0.1649096	0.1649069	0.0000009
EARTH	2061-04-01 16:41	< 1 min	0.1446911	0.1446895	0.0000005
EARTH	2080-08-27 21:12	< 1 min	0.0617642	0.0617593	0.0000016
EARTH	2084-04-13 13:45	< 1 min	0.1975401	0.1975366	0.0000012
EARTH	2091-08-23 14:59	< 1 min	0.0893927	0.0893898	0.0000009
EARTH	2095-04-06 19:40	< 1 min	0.1222585	0.1222583	0.0000001
EARTH	2106-03-28 10:47	< 1 s	0.1986230	0.1986226	0.0000001
EARTH	2114-08-30 13:47	< 1 s	0.1766161	0.1766152	0.0000003
EARTH	2125-08-28 02:20	< 1 min	0.0285882	0.0285869	0.0000004

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
275.20056352	228.93635253	0.02040671	MINIMUM
79.58827133	90.56893453	0.12196322	MINIMUM
356.50739827	337.56522982	0.44642088	SADDLE
177.71809810	161.30420146	0.58546442	SADDLE
358.23485526	160.44672839	1.56220444	SADDLE
180.10815418	342.74374500	2.55569850	MAXIMUM

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