Asteroids

2025BY4 help

Last update: 2026-06-04 23:11 UTC

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.952

Aphelion (Q)

3.155

Eccentricity (e)

0.537

Inclination (i)

6.1

deg

Orbit period (P)

1074.9

Earth MOID

0.00533

U parameter

8.0

Next Earth close approach

Date

2081-04-24

Nominal distance (from Earth center)

0.09276

13877129

Maximum Brightness

21.3

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

23.5

mag

Diameter

50 - 120*

Taxonomic type

Rotation period (T)

Discovery Information

Discovery Date

2025-01-23

Observatory

University of Arizona Mt. Lemmon Survey

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

2.053542

1-sigma variation

0.003370

Unit

Eccentricity (e)

Value

0.536613

1-sigma variation

0.000765

Unit

Inclination (i)

Value

6.0754

1-sigma variation

0.0052

Unit

Long. of Ascending Node (Ω)

Value

339.5491

1-sigma variation

0.0092

Unit

Arg. of Perihelion (ω)

Value

203.7445

1-sigma variation

0.0064

Unit

Mean Anomaly (M)

Value

152.43464

1-sigma variation

0.37212

Unit

Perihelion distance

Value

0.951584

1-sigma variation

Unit

Aphelion distance

Value

3.155500

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

1.864073

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

-0.009864

1-sigma variation

Unit

MOID

Value

0.005327

1-sigma variation

Unit

Orbit Period

Value

1074.8647

1-sigma variation

Unit

U parameter

Value

8.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.13585E-5	2.57819E-6	1.75736E-5	3.10592E-5	-2.13485E-5	-1.25413E-3
e	2.57819E-6	5.85204E-7	3.98894E-6	7.04982E-6	-4.84539E-6	-2.84666E-4
i	1.75736E-5	3.98894E-6	2.71925E-5	4.80468E-5	-3.30041E-5	-1.94036E-3
Ω	3.10592E-5	7.04982E-6	4.80468E-5	8.49494E-5	-5.84349E-5	-3.42934E-3
ω	-2.13485E-5	-4.84539E-6	-3.30041E-5	-5.84349E-5	4.03571E-5	2.35711E-3
M	-1.25413E-3	-2.84666E-4	-1.94036E-3	-3.42934E-3	2.35711E-3	1.38473E-1

Date of computation: 2026-06-04 23:11 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

Unit

Source

[-]

Quality

Value

Unit

Source

[-]

Amplitude

Value

Unit

mag

Source

[-]

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

23.518

Unit

mag

Source

[1]

Slope Parameter (G)

Value

0.15**

Unit

Source

[1]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[2]

Diameter

Value

50 - 120*

Unit

Source

[2]

Color Index Information

Color Index Information

Value

Unit

Source

Color Index Information

Value

Unit

mag

Source

[-]

Sightings

Sightings

Value

Unit

Source

Sightings

Value

Unit

Source

[-]

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Sources

No.	Name	Additional
[1]	ESA Aegis	ESA orbit determination and impact monitoring system
[2]	Estimation	Estimated from absolute magnitude

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

Unit

Source

[1]

Unobserved

Value

517

Unit

Source

[1]

Normalized RMS of residuals

Value

0.653438

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2025-01-23.400781

Unit

Source

[2]

Last Observation

Value

2025-02-09.47349

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

58 (0)

Unit

Source

[1]

Radar Summary

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

Radar

Value

Unit

Source

First Observation

Value

Unit

Source

[-]

Last Observation

Value

Unit

Source

[-]

Delay (Discarded)

Value

0 (0)

Unit

Source

[-]

Doppler (Discarded)

Value

0 (0)

Unit

Source

[-]

Total Radar Observations (Discarded)

Value

0 (0)

Unit

Source

[-]

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

Filters

Initial Date: *

Final Date: *

Normalised Only accepted

Max residual (arcsec):

* - these fields are required

Plot

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

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Time step:*

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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 2025BY4 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	1975-05-02 04:18	> 1 mo	0.0995440	0.0896506	0.1919689
EARTH	1978-02-10 16:40	> 1 mo	0.0898574	0.0168694	0.6242768
EARTH	2022-04-20 02:32	> 1 w	0.0843513	0.0818318	0.0073891
EARTH	2025-02-09 21:19	< 1 min	0.1139744	0.1135928	0.0001272
EARTH	2081-04-24 02:04	> 1 mo	0.0927629	0.0767983	0.3320482
EARTH	2084-03-05 04:24	> 1 mo	0.0115832	0.0103805	0.2441410
EARTH	2087-02-12 22:09	> 1 mo	0.1372898	0.0032096	5.4320977

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
345.31086079	54.77592060	0.00571374	MINIMUM
1.83810631	264.16608586	1.95420827	SADDLE
180.66431958	262.54708664	2.15373731	SADDLE
180.39671501	82.39910871	4.15308262	MAXIMUM

Download:

MOID Plots

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