Asteroids

471240 2011BT15 help

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

Orbital Properties

Epoch

61200.0

MJD

Orbit type

Apollo

Perihelion (q)

0.902

Aphelion (Q)

1.684

Eccentricity (e)

0.302

Inclination (i)

1.7

deg

Orbit period (P)

537.0

Earth MOID

0.00054

U parameter

0.0

Next Earth close approach

Date

2038-12-28

Nominal distance (from Earth center)

0.03451

5162057

Maximum Brightness

19.2

mag

Risk

Object is not in risk list

Physical Properties

Absolute Magnitude (H)

21.6

mag

Diameter

130 - 280*

Taxonomic type

Rotation period (T)

0.1091

Discovery Information

Discovery Date

2011-01-24

Observatory

Pan-STARRS 1, Haleakala

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

1.292908

1-sigma variation

3.537E-9

Unit

Eccentricity (e)

Value

0.302408

1-sigma variation

1.731E-8

Unit

Inclination (i)

Value

1.6619

1-sigma variation

2.421E-6

Unit

Long. of Ascending Node (Ω)

Value

105.3512

1-sigma variation

0.0001

Unit

Arg. of Perihelion (ω)

Value

308.8149

1-sigma variation

0.0001

Unit

Mean Anomaly (M)

Value

189.56893

1-sigma variation

0.00001

Unit

Perihelion distance

Value

0.901922

1-sigma variation

Unit

Aphelion distance

Value

1.683893

1-sigma variation

Unit

Asc. Node-Earth Sep.

Value

0.003717

1-sigma variation

Unit

Desc. Node-Earth Sep.

Value

0.433144

1-sigma variation

Unit

MOID

Value

0.000542

1-sigma variation

Unit

Orbit Period

Value

536.9695

1-sigma variation

Unit

U parameter

Value

0.0

1-sigma variation

Unit

Covariance Matrix

	a	e	i	Ω	ω	M
a	1.25106E-17	-2.50167E-17	2.94290E-15	3.46494E-14	-2.51904E-14	-4.39894E-14
e	-2.50167E-17	2.99756E-16	-5.15072E-15	-4.17531E-15	-6.34283E-14	1.35636E-13
i	2.94290E-15	-5.15072E-15	5.85931E-12	8.69999E-11	-8.41870E-11	-1.03563E-11
Ω	3.46494E-14	-4.17531E-15	8.69999E-11	4.01343E-9	-4.00590E-9	-1.01164E-10
ω	-2.51904E-14	-6.34283E-14	-8.41870E-11	-4.00590E-9	4.04497E-9	3.69730E-11
M	-4.39894E-14	1.35636E-13	-1.03563E-11	-1.01164E-10	3.69730E-11	1.81149E-10

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

0.1091

Unit

Source

[2]

[3]

Quality

Value

Unit

Source

[2]

[3]

Amplitude

Value

0.61

Unit

mag

Source

[2]

[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

[1]

Absolute Magnitude (H)
Slope Parameter (G)

H / G

Value

Unit

Source

Absolute Magnitude (H)

Value

21.617

Unit

mag

Source

[4]

Slope Parameter (G)

Value

0.15**

Unit

Source

[4]

Albedo
Diameter

Size and albedo

Value

Unit

Source

Albedo

Value

0.05 - 0.25

Unit

Source

[5]

Diameter

Value

130 - 280*

Unit

Source

[5]

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

[1]

[6]

Download this part as:

Sources

No.	Name	Additional
[1]	EARN	1.) Kuroda, D. et al. (2014) PASJ 66, 51. (Visible-wavelength spectroscopy of subkilometer-sized near-Earth asteroids with a low delta-v) (89136,136923,141018,163000,214869, 253062,311925,363305,2009SC15,2009SQ104,2011BT15)
[2]	EARN	1.) Warner, B.D. et al. (2014) MPB 41, 157-168. (NEAR-EARTH ASTEROID LIGHTCURVE ANALYSIS AT CS3-PALMER DIVIDE STATION: 2014 JANUARY-MARCH) (1943,4055,4954,25916,35107,40267,53435, 68031,85990,86039,138127,143409,243566,275677,277570,294739, 357622,377097,1995CR,2006DP14,2009CT,2009QF31,2011BT15, 2012AU10,2013XV8,2013YZ13,2013PD21,2013XF22,2013YZ37, 2013WT44,2014CR,2014EM,2014BR8,2014CG13,2014CU13,2014EY24, 2014AY28,2014EL45,2014BR57,2014DX110)
[3]	EARN	1.) Warner, B.D. (2014) Minor Planet Bul. 41, 157-168.
[4]	ESA Aegis	ESA orbit determination and impact monitoring system
[5]	Estimation	Estimated from absolute magnitude
[6]	EARN	1.) href="http://echo.jpl.nasa.gov/asteroids/index.html">JPL's NEO Radar Detection Program Webpage

Observational Information

Arc Length
Unobserved
Normalized RMS of residuals

Arc Information

Value

Unit

Source

Arc Length

Value

6863

Unit

Source

[1]

Unobserved

Value

147

Unit

Source

[1]

Normalized RMS of residuals

Value

0.725466

Unit

Source

[1]

Astrometry Summary

First Observation
Last Observation
Total Optical Observations (Discarded)

Optical

Value

Unit

Source

First Observation

Value

2007-07-30.274387

Unit

Source

[2]

Last Observation

Value

2026-05-14.20378

Unit

Source

[2]

Total Optical Observations (Discarded)

Value

246 (9)

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):

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Plot

Computation parameters

As seen from:

Initial Date: *

Final Date: *

Output option:

One line per time step

Time step:*

* - these fields are required

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 471240 2011BT15 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	1980-01-18 12:43	1.9	0.1438901	0.1438157	0.0000248
MARS	1980-06-12 22:15	< 1 min	0.0296622	0.0296312	0.0000104
EARTH	1983-01-03 00:54	< 1 min	0.0103692	0.0103638	0.0000018
EARTH	1985-09-23 22:24	< 1 min	0.0306348	0.0306337	0.0000004
MARS	2001-02-21 09:08	< 1 min	0.0277443	0.0277438	0.0000001
EARTH	2013-12-28 15:32	< 1 min	0.0322262	0.0322260	0.0000001
EARTH	2016-09-15 09:21	< 1 s	0.0508521	0.0508520	0.0000000
EARTH	2038-12-28 15:00	< 1 min	0.0345062	0.0345047	0.0000005
EARTH	2041-09-09 18:59	< 1 s	0.1104387	0.1104384	0.0000001
MARS	2056-02-14 15:14	< 1 min	0.0388946	0.0388921	0.0000008
EARTH	2060-12-25 14:38	1.8	0.0434064	0.0433960	0.0000035
EARTH	2063-09-06 13:15	< 1 min	0.1618746	0.1618683	0.0000021
EARTH	2080-01-17 19:24	1.0	0.1259393	0.1259038	0.0000118
EARTH	2082-09-24 01:08	3.3	0.0319147	0.0318987	0.0000054
EARTH	2102-01-07 16:38	17.0	0.0094458	0.0091955	0.0000834
EARTH	2104-10-26 06:16	1139.6	0.0802892	0.0788523	0.0004804
EARTH	2107-09-13 02:58	317.0	0.1121930	0.1033513	0.0029556

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Stationary Points

Ecc. an. ast.	Ecc. an. Earth	Distance in au	Classification
37.70871853	359.79303404	0.00054178	MINIMUM
317.33938474	254.50698308	0.02779644	MINIMUM
356.50753895	305.85512693	0.09065181	SADDLE
178.47164700	128.20785635	0.67396199	SADDLE
357.26571345	126.89631562	1.91222892	SADDLE
178.63903040	308.34040249	2.67332192	MAXIMUM

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MOID Plots

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