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Showing posts with label binary asteroid. Show all posts
Showing posts with label binary asteroid. Show all posts

Saturday, October 14, 2017

304873 (2007 RD148) vs 95750 (2003 ED28)

These two main belt asteroids have similar obit parameters.
Their orbits are well known, in fact they are numbered objects and their orbit condition code is 0

Using the JPL Small-Body Database Browser, we can see:

304873 (2007 RD148)

Classification: Main-belt Asteroid          SPK-ID: 2304873
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]

Orbital Elements at Epoch 2458000.5 (2017-Sep-04.0) TDB
Reference: JPL 8 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .112706956254304 8.1867e-08
a 2.356322451918862 3.2148e-08 au
q 2.090748520409409 2.1203e-07 au
i 7.649992278043358 1.0168e-05 deg
node 27.84270465718106 5.3513e-05 deg
peri 271.5923935241259 6.9656e-05 deg
M 320.2483032081591 4.5862e-05 deg
tp 2458146.382661936927
(2018-Jan-27.88266194)
0.00016876 JED
period 1321.145071424301
3.62
2.7037e-05
7.402e-08
d
yr
n .2724908927767416 5.5765e-09 deg/d
Q 2.621896383428315 3.5771e-08 au
Orbit Determination Parameters
   # obs. used (total)      122  
   data-arc span      5996 days (16.42 yr)  
   first obs. used      2000-11-30  
   last obs. used      2017-05-01  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   fit RMS      .62685  
   data source      ORB  
   producer      Otto Matic  
   solution date      2017-May-15 18:17:37  

Additional Information
 Earth MOID = 1.09229 au 
 Jupiter MOID = 2.56959 au 
 T_jup = 3.534 


95750 (2003 ED28)

Classification: Main-belt Asteroid          SPK-ID: 2095750
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]

Orbital Elements at Epoch 2458000.5 (2017-Sep-04.0) TDB
Reference: JPL 15 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1131879964824657 5.3076e-08
a 2.356588129411903 1.9765e-08 au
q 2.089850640509408 1.2124e-07 au
i 7.650207304601344 7.0217e-06 deg
node 27.83162309848563 3.2879e-05 deg
peri 271.7844693300495 4.7721e-05 deg
M 252.9376849706002 3.6597e-05 deg
tp 2458393.468812675760
(2018-Oct-01.96881268)
0.00013583 JED
period 1321.368518179582
3.62
1.6624e-05
4.551e-08
d
yr
n .2724448138782385 3.4276e-09 deg/d
Q 2.623325618314398 2.2002e-08 au
Orbit Determination Parameters
   # obs. used (total)      464  
   data-arc span      7627 days (20.88 yr)  
   first obs. used      1996-04-17  
   last obs. used      2017-03-05  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   fit RMS      .57403  
   data source      ORB  
   producer      Otto Matic  
   solution date      2017-Apr-11 13:52:05  

Additional Information
 Earth MOID = 1.09141 au 
 Jupiter MOID = 2.56949 au 
 T_jup = 3.533 

I tried to simulate their behavior in the past to investigate whether they might be related.

Simulation set-up
Mercury6 Integrator

reference:
J.E.Chambers (1999) 
A Hybrid Symplectic Integrator that Permits Close Encounters between Massive Bodies''. Monthly Notices of the Royal Astronomical Society, vol 304, pp793-799.

           Integration parameters
           ----------------------

   Algorithm: Bulirsch-Stoer (conservative systems)

   Integration start epoch:         2458000.5000000 days
   Integration stop  epoch:      -100000000.0000000
   Output interval:                     100.000
   Output precision:                 medium

   Initial timestep:                0.050 days
   Accuracy parameter:              1.0000E-12
   Central mass:                    1.0000E+00 solar masses
   J_2:                              0.0000E+00
   J_4:                              0.0000E+00
   J_6:                              0.0000E+00
   Ejection distance:               1.0000E+02 AU
   Radius of central body:          5.0000E-03 AU


In order to perform the simulation I generated 30 clones for each asteroids (same average orbital parameters as the nominal ones and standard deviation almost about the one calculated by JPL).

Thus, I evaluated 900 couples to check whether there was a moment in the past when two clones were very near with a very low relative velocity.
In particular, I used two arbitrary thresholds to detect interesting couples:
  • distance less than 1 Lunar Distance - about 0.0020 AU
  • relative velocity less than 1 m/s

The clone generation and the couples evaluation have been done using scripts written in R.

Simulation Results
The results are interesting because 770 out of 900 couples satisfy the thresholds mentioned above.

Distance between clones (km):

   Min. 1st Qu.  Median    Mean  3rd Qu.   Max.     sd
    961    4540    6849   13342   21245  126502    11832



Relative velocity (m/s) when at minimum distance:

   Min. 1st Qu.  Median    Mean   3rd Qu.  Max.     sd
   0.33    0.57    0.77    0.74    0.92    1.00     0.18



Time of minimum distance (Years):
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max.     sd
-276373 -115975 -114199 -130260 -113592 -109542    42281


In a graphical form:






The couple that went very near
Note that the time step is 100 days (this is consistent with a physical separation):




Conclusion
This does not prove that the asteroids originated from a common body but I think that this is certainly a possibility.

Kind Regards,
Alessandro Odasso



Monday, July 10, 2017

276353 (2002 UY20) vs 57202 (2001 QJ53)

276353 (2002 UY20) vs 57202 (2001 QJ53)

Same approach described in the previous posts.

276353 (2002 UY20)

Classification: Main-belt Asteroid          SPK-ID: 2276353
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]

Orbital Elements at Epoch 2458000.5 (2017-Sep-04.0) TDB
Reference: JPL 8 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1562105639420963 6.3914e-08
a 2.337601777404309 2.6617e-08 au
q 1.972443685483935 1.5861e-07 au
i 4.252343536114911 6.8871e-06 deg
node 23.41388838094758 0.0001045 deg
peri 35.95235952421835 0.00010784 deg
M 38.09017324814934 2.7256e-05 deg
tp 2457862.377424660816
(2017-Apr-18.87742466)
9.8187e-05 JED
period 1305.431897045054
3.57
2.2296e-05
6.104e-08
d
yr
n .2757708010773199 4.7101e-09 deg/d
Q 2.702759869324683 3.0775e-08 au
Orbit Determination Parameters
   # obs. used (total)      115  
   data-arc span      5111 days (13.99 yr)  
   first obs. used      2002-10-28  
   last obs. used      2016-10-25  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   fit RMS      .70803  
   data source      ORB  
   producer      Otto Matic  
   solution date      2017-Apr-10 16:21:05  

Additional Information
 Earth MOID = .986707 au 
 Jupiter MOID = 2.62843 au 
 T_jup = 3.546 

57202 (2001 QJ53)

Classification: Main-belt Asteroid          SPK-ID: 2057202
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]

Orbital Elements at Epoch 2458000.5 (2017-Sep-04.0) TDB
Reference: JPL 17 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1557724906162496 4.4578e-08
a 2.338080038545681 1.0974e-08 au
q 1.973871487681283 1.03e-07 au
i 4.250626760813153 5.0566e-06 deg
node 23.42499161765863 6.5966e-05 deg
peri 36.16096420351912 6.8003e-05 deg
M 103.6361139081139 1.6156e-05 deg
tp 2457624.579415793553
(2016-Aug-24.07941579)
5.793e-05 JED
period 1305.832544380318
3.58
9.1935e-06
2.517e-08
d
yr
n .275686190813109 1.9409e-09 deg/d
Q 2.702288589410078 1.2683e-08 au
Orbit Determination Parameters
   # obs. used (total)      743  
   data-arc span      16797 days (45.99 yr)  
   first obs. used      1971-03-25  
   last obs. used      2017-03-20  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   fit RMS      .57656  
   data source      ORB  
   producer      Otto Matic  
   solution date      2017-Apr-11 18:07:27  

Additional Information
 Earth MOID = .988199 au 
 Jupiter MOID = 2.62768 au 
 T_jup = 3.546 

Simulation Results (note, Time 0 is JD 0 --> 4713 B.C.)



Kind Regards,
Alessandro Odasso

(2012 TQ236) vs 341874 (2008 GB53)

(2012 TQ236) vs 341874 (2008 GB53)

This is another interesting couple (same simulation approach described in the previous post).

(2012 TQ236)

Classification: Main-belt Asteroid          SPK-ID: 3612103
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters ]

[ show orbit diagram ]

Orbital Elements at Epoch 2458000.5 (2017-Sep-04.0) TDB
Reference: JPL 6 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1666400181863286 5.5861e-06
a 2.181322170293682 2.3565e-06 au
q 1.817826604165701 1.4148e-05 au
i 3.706000259833047 2.3889e-05 deg
node 130.8866173415038 0.00037736 deg
peri 225.066713022466 0.0031505 deg
M 207.0510430328395 0.0025163 deg
tp 2458500.444927002519
(2019-Jan-16.94492700)
0.0088584 JED
period 1176.73358020709
3.22
0.0019068
5.221e-06
d
yr
n .3059316110760132 4.9574e-07 deg/d
Q 2.544817736421663 2.7491e-06 au
Orbit Determination Parameters
   # obs. used (total)      25  
   data-arc span      1078 days (2.95 yr)  
   first obs. used      2012-09-23  
   last obs. used      2015-09-06  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      3  
   fit RMS      .65133  
   data source      ORB  
   producer      Otto Matic  
   solution date      2017-Apr-07 17:13:15  

Additional Information
 Earth MOID = .814749 au 
 Jupiter MOID = 2.88145 au 
 T_jup = 3.660 

341874 (2008 GB53)

Classification: Main-belt Asteroid          SPK-ID: 2341874
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]

Orbital Elements at Epoch 2458000.5 (2017-Sep-04.0) TDB
Reference: JPL 4 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1669528069531998 1.1233e-07
a 2.180875946944555 3.0388e-08 au
q 1.816772585985444 2.5263e-07 au
i 3.706556681959036 1.2083e-05 deg
node 130.8943547687225 0.0001365 deg
peri 225.0440620302201 0.00014182 deg
M 182.8634290772902 3.7363e-05 deg
tp 2458579.329428649479
(2019-Apr-05.82942865)
0.00013018 JED
period 1176.372519962207
3.22
2.4587e-05
6.732e-08
d
yr
n .306025509684267 6.3962e-09 deg/d
Q 2.544979307903666 3.5462e-08 au
Orbit Determination Parameters
   # obs. used (total)      78  
   data-arc span      5842 days (15.99 yr)  
   first obs. used      2001-02-02  
   last obs. used      2017-01-31  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   fit RMS      .48759  
   data source      ORB  
   producer      Otto Matic  
   solution date      2017-Apr-10 08:47:34  

Additional Information
 Earth MOID = .813692 au 
 Jupiter MOID = 2.88132 au 
 T_jup = 3.660 

Simulation results ((note, Time 0 is JD 0 --> 4713 B.C.)

Kind Regards,
Alessandro Odasso