Asteroids

54509 YORP help

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

Orbital Properties

Epoch

61000.0

MJD

Orbit type

Apollo

Perihelion (q)

0.775

Aphelion (Q)

1.237

Eccentricity (e)

0.230

Inclination (i)

1.6

deg

Orbit period (P)

368.5

Earth MOID

0.00050

U parameter

0.0

Next Earth close approach

Date

2099-12-25

Nominal distance (from Earth center)

0.17735

26531728

Maximum Brightness

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

22.6

mag

Diameter

Taxonomic type

Rotation period (T)

0.2030

Discovery Information

Discovery Date

2000-08-03

Observatory

Lincoln Laboratory ETS, New Mexico

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

1.005856

1-sigma variation

1.798E-9

Unit

Eccentricity (e)

Value

0.229964

1-sigma variation

1.192E-7

Unit

Inclination (i)

Value

1.5995

1-sigma variation

4.350E-6

Unit

Long. of Ascending Node (Ω)

Value

278.1852

1-sigma variation

0.0001

Unit

Arg. of Perihelion (ω)

Value

278.9989

1-sigma variation

0.0001

Unit

Mean Anomaly (M)

Value

130.15656

1-sigma variation

0.00001

Unit

Perihelion distance

Value

0.774546

1-sigma variation

Unit

Aphelion distance

Value

1.237167

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

-0.098169

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.004200

1-sigma variation

Unit

MOID

Value

0.000495

1-sigma variation

Unit

Orbit Period

Value

368.4702

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	3.23227E-18	-2.14149E-16	3.89410E-15	6.97491E-14	-6.13032E-14	-1.93348E-14
e	-2.14149E-16	1.42027E-14	-2.64572E-13	-4.71822E-12	4.15583E-12	1.27380E-12
i	3.89410E-15	-2.64572E-13	1.89237E-11	3.21401E-10	-3.07990E-10	-2.62690E-11
Ω	6.97491E-14	-4.71822E-12	3.21401E-10	5.48029E-9	-5.24518E-9	-4.80146E-10
ω	-6.13032E-14	4.15583E-12	-3.07990E-10	-5.24518E-9	5.03306E-9	4.29430E-10
M	-1.93348E-14	1.27380E-12	-2.62690E-11	-4.80146E-10	4.29430E-10	1.28786E-10

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

0.2030

Unit

Source

[3]

Quality

Value

Unit

Source

[3]

Amplitude

Value

0.77

Unit

mag

Source

[3]

Rotation Direction

Value

PRO

Unit

Source

[1]

Spinvector L

Value

180

Unit

Source

[1]

Spinvector B

Value

-85

Unit

Source

[1]

Taxonomy
Taxonomy (all)

Taxonomy

Value

Unit

Source

Taxonomy

Value

Unit

Source

[2]

Taxonomy (all)

Value

S/V

Unit

Source

[2]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

22.6

22.633

Unit

mag

Source

[4]

[5]

Slope Parameter (G)

Value

0.15**

Unit

mag

Source

[5]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.56

Unit

Source

[6]

Diameter

Value

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

Visual S

Radar R

Unit

Source

[2]

[7]

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Sources

No.	Name	Additional
[1]	EARN	1.) Taylor, P.A. et al. (2007) Science 316,272-274. (Spin rate of asteroid (54509) 2000 PH5 increasing due to the YORP effect)
[2]	EARN	1.) Gietzen, K.M. & C.H.S. Lacy (2007) LPSC 38, 1104. (Visible and near infrared spectra of main belt and near Earth asteroids) (1036,3908,7753,22771,54509,66251,68950,J99JV3, K03YQ117)
[3]	EARN	1.) Hergenrother, C.W. & R.J. Whiteley (2011) Icarus 214, 194-209. (A survey of small fast rotating asteroids among the near-Earth asteroid population) (new data for 53 NEAs) 2.) Taylor, P.A. et al. (2007) Science 316,272-274. (Spin rate of asteroid (54509) 2000 PH5 increasing due to the YORP effect) 3.) Petr Pravec's Ondrejov NEO Photometric Program Webpage "Prepublished Periods" 4.) 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) 5.) Hergenrother, C.W. & R.J. Whiteley (2005) B.A.A.S. 37, 636-637. (The Rotation State of Small Rapidly Rotating Asteroids) 6.) Lowry S.C. et al. (2007) Science 316,272-277. (Direct detection of the asteroidal YORP effect) 7.) 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)
[4]	EARN	1.) 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)
[5]	ESA Aegis	ESA orbit determination and impact monitoring system
[6]	EARN	1.) Trilling, D.E.; Mommert, M.; Hora, J.; Chesley, S.; et al. (2016) Astron. J. 152, A172. 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.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage 2.) Margot, J.-L. et al. (2003) B.A.A.S. 35, 960. (The dynamics and shape of the minor planet 2000 PH5)

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

1827

Unit

Source

[1]

Unobserved

Value

7366

Unit

Source

[1]

Normalized RMS of residuals

Value

0.509632

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2000-08-03.1615

Unit

Source

[2]

Last Observation

Value

2005-08-03.93465

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

548 (4)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

2001-07-27

Unit

Source

[3]

Last Observation

Value

2004-07-28

Unit

Source

[3]

Delay (Discarded)

Value

4 (0)

Unit

Source

[1]

Doppler (Discarded)

Value

1 (0)

Unit

Source

[1]

Total Radar Observations (Discarded)

Value

5 (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 54509 YORP 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	1996-08-02 07:40	< 1 s	0.1987677	0.1987674	0.0000001
EARTH	1997-07-31 10:25	< 1 s	0.1491780	0.1491777	0.0000001
EARTH	1998-07-29 18:20	< 1 s	0.1020959	0.1020958	0.0000001
EARTH	1999-07-28 08:03	< 1 s	0.0588804	0.0588803	0.0000000
EARTH	2000-07-26 05:31	< 1 s	0.0241375	0.0241374	0.0000000
EARTH	2001-07-25 19:11	< 1 s	0.0120175	0.0120175	0.0000000
EARTH	2002-07-25 20:34	< 1 s	0.0115741	0.0115741	0.0000000
EARTH	2003-07-26 02:02	< 1 s	0.0115731	0.0115731	0.0000000
EARTH	2004-07-25 10:15	< 1 s	0.0128183	0.0128183	0.0000000
EARTH	2005-07-26 16:39	< 1 s	0.0358869	0.0358869	0.0000000
EARTH	2006-07-28 13:57	< 1 s	0.0768190	0.0768189	0.0000000
EARTH	2007-07-30 19:49	< 1 s	0.1237747	0.1237746	0.0000001
EARTH	2008-08-01 02:48	< 1 s	0.1731271	0.1731269	0.0000001
EARTH	2099-12-25 13:52	< 1 min	0.1773536	0.1773502	0.0000011
EARTH	2100-12-28 00:08	< 1 min	0.1255306	0.1255274	0.0000010
EARTH	2101-12-30 04:25	< 1 min	0.0769538	0.0769511	0.0000009
EARTH	2103-01-01 01:48	< 1 min	0.0335000	0.0334980	0.0000006
EARTH	2104-01-02 05:03	< 1 min	0.0052630	0.0052628	0.0000001
EARTH	2104-12-30 05:46	< 1 min	0.0716663	0.0716611	0.0000017
EARTH	2105-12-27 15:19	< 1 min	0.1454346	0.1454246	0.0000033

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
275.49920586	357.11184200	0.00045791	MINIMUM
92.00899368	200.50678375	0.01162166	MINIMUM
4.86033943	99.90200160	0.22865565	SADDLE
183.00462680	278.07805547	0.24114630	SADDLE
4.99656798	280.08153114	1.77211677	SADDLE
183.19578342	98.23263105	2.23870400	MAXIMUM

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MOID Plots

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