"Pseudo-MPEC" for WJ2B5AC = INTEGRAL = 2002-048A = NORAD 27540

Created 2015 Nov 20 15:20:09 UT using Find_Orb

Click here for more recent observations and elements for this object.

This object was tracked as an "unknown" throughout much of 2015, with the designation WJ2B5AC. Jonathan McDowell figured out that it was actually INTEGRAL. INTEGRAL had been tracked before in 2002. Back then, we were able to identify it easily; the positions matched those computed from known orbital elements nicely.

However, INTEGRAL changed its orbit drastically in early 2015. The orbital elements from Space-Track.org just followed the nominal trajectory, not taking that maneuver into account. So when WJ2B5AC was "discovered", we were scratching our heads as to what we might have here. The fact that we hadn't seen it before May 2015, and then started seeing it monthly, made me think it must be a recent object. Fortunately, as Jonathan's story above describes, we eventually did figure it out.

The residuals are really bad. Until we got an ID on the object, I thought this might be due to the object having an orbital period very close to 8/3 days, with a low perigee, and that some spherical harmonic effects in the earth's gravitational field were causing trouble. I now know that the real problem is that the object does some small maneuvers on a frequent basis.

Click here for TLEs (Two-Line Elements) for this object. Note that because the object actually maneuvers a bit, those TLEs are probably close to pure garbage for dates far from the 2015 June-November range of observations used to compute them.

Astrometry:
     WJ2B5AC  C2015 05 12.36599 18 48 54.55 +49 43 43.6         x16.7 VqNEOCP703
     WJ2B5AC  C2015 05 12.36900 18 49 08.85 +49 46 46.9         x16.7 VqNEOCP703
     WJ2B5AC  C2015 05 12.37200 18 49 23.16 +49 49 49.2         x16.7 VqNEOCP703
     WJ2B5AC  C2015 05 12.37500 18 49 37.27 +49 52 49.0         x16.7 VqNEOCP703
     WJ2B5AC  C2015 05 12.41016 18 52 14.29 +50 24 47.9         x17.3 VqNEOCPI52
     WJ2B5AC  C2015 05 12.41045 18 52 15.56 +50 25 02.9         x17.4 VqNEOCPI52
     WJ2B5AC  C2015 05 12.41106 18 52 18.18 +50 25 33.7         x17.0 VqNEOCPI52
     WJ2B5AC  C2015 05 12.42114 18 53 00.54 +50 33 42.0         x            I52
     WJ2B5AC  C2015 05 12.42156 18 53 02.22 +50 34 01.3         x            I52
     WJ2B5AC  C2015 05 12.42197 18 53 04.09 +50 34 21.6         x            I52
     WJ2B5AC  C2015 05 12.42793 18 53 28.87 +50 38 56.1         x            I52
     WJ2B5AC  C2015 05 12.42835 18 53 30.53 +50 39 14.6         x            I52
     WJ2B5AC  C2015 05 12.42876 18 53 32.29 +50 39 34.2         x            I52
     WJ2B5AC  C2015 05 12.42917 18 53 33.84 +50 39 51.5         x            I52
     WJ2B5AC  C2015 05 12.43298 18 53 48.80 +50 42 46.3         x16.4 V      703
     WJ2B5AC  C2015 05 12.43322 18 53 49.82 +50 42 57.5         x16.3 V      703
     WJ2B5AC  C2015 05 12.43347 18 53 50.79 +50 43 08.8         x16.3 V      703
     WJ2B5AC  C2015 05 12.43372 18 53 51.80 +50 43 18.9         x16.2 V      703
     WJ2B5AC KC2015 05 12.45093 18 57 01.61 +50 40 48.4         x16.5 V      U69
     WJ2B5AC KC2015 05 12.45261 18 57 09.05 +50 42 03.0         x16.5 V      U69
     WJ2B5AC KC2015 05 12.45454 18 57 17.54 +50 43 27.5         x16.5 V      U69
     WJ2B5AC KC2015 05 12.45620 18 57 24.90 +50 44 39.8         x16.5 V      U69
     WJ2B5AC KC2015 05 12.87488120 08 49.92 +51 20 37.4         x15.5 R      J95
     WJ2B5AC KC2015 05 12.87711220 09 15.81 +51 22 01.1         x15.2 R      J95
     WJ2B5AC KC2015 05 12.87984520 09 47.51 +51 23 43.4         x15.4 R      J95
     WJ2B5AC KC2015 05 12.88222020 10 14.91 +51 25 13.0         x15.5 R      J95
     WJ2B5AC KC2015 05 13.11708620 49 31.20 +53 34 49.9         x15.7 R      J95
     WJ2B5AC KC2015 05 13.11881320 49 46.08 +53 35 25.8         x15.7 R      J95
     WJ2B5AC KC2015 05 13.12076420 50 02.87 +53 36 05.7         x15.9 R      J95
     WJ2B5AC KC2015 05 16.88189616 06 05.23 +15 57 18.2         x13.0 R      J95
     WJ2B5AC KC2015 05 16.88315416 06 33.35 +16 09 49.5         x12.9 R      J95
     WJ2B5AC KC2015 05 16.88439116 07 00.73 +16 21 59.9         x13.0 R      J95
     WJ2B5AC KC2015 05 16.88556216 07 26.48 +16 33 25.2         x13.0 R      J95
     WJ2B5AC KC2015 05 16.88678216 07 53.08 +16 45 11.5         x12.8 R      J95
     WJ2B5AC KC2015 05 17.38254 17 54 16.14 +45 09 50.9         x15.8 V      H06
     WJ2B5AC KC2015 05 17.38736 17 54 39.50 +45 15 48.5         x15.8 V      H06
     WJ2B5AC KC2015 05 26.91130822 50 34.66 +47 08 31.4         x14.8 R      J95
     WJ2B5AC KC2015 05 26.91175722 50 44.94 +47 07 59.7         x15.0 R      J95
     WJ2B5AC KC2015 05 26.91234222 50 58.48 +47 07 17.8         x14.9 R      J95
     WJ2B5AC KC2015 05 26.91289822 51 11.27 +47 06 38.5         x14.8 R      J95
     WJ2B5AC KC2015 05 26.91350122 51 25.23 +47 05 55.3         x15.0 R      J95
     WJ2B5AC  C2015 06 21.34528 18 48 52.50 +50 37 20.6          16.0 VqNEOCP703
     WJ2B5AC  C2015 06 21.34828 18 49 04.40 +50 39 07.8          16.0 VqNEOCP703
     WJ2B5AC  C2015 06 21.35129 18 49 16.29 +50 40 55.2          16.1 VqNEOCP703
     WJ2B5AC  C2015 06 21.35429 18 49 28.29 +50 42 39.3          16.1 VqNEOCP703
     WJ2B5AC  C2015 06 21.39820 18 52 27.90 +51 03 23.3          16.3 VqNEOCPI52
     WJ2B5AC  C2015 06 21.39851 18 52 29.24 +51 03 30.1          16.2 VqNEOCPI52
     WJ2B5AC  C2015 06 21.39883 18 52 30.57 +51 03 37.5          16.3 VqNEOCPI52
     WJ2B5AC  C2015 06 21.39914 18 52 31.88 +51 03 44.6          16.3 VqNEOCPI52
     WJ2B5AC KC2015 07 10.00587418 51 50.93 +50 04 42.8          15.2 R D0518J95
     WJ2B5AC KC2015 07 10.00796518 52 02.03 +50 05 50.2          15.1 R D0518J95
     WJ2B5AC KC2015 07 10.00999118 52 12.81 +50 06 54.9          15.1 R D0518J95
     WJ2B5AC KC2015 08 08.92135920 39 35.15 +53 07 35.4          16.5 R D0519J95
     WJ2B5AC KC2015 08 08.92608620 40 12.65 +53 08 23.3          16.6 R D0519J95
     WJ2B5AC KC2015 08 08.93083620 40 50.29 +53 09 06.5          16.5 R D0519J95
     WJ2B5AC KC2015 08 27.88938722 00 43.45 +50 51 32.8          15.2 R D0520J95
     WJ2B5AC KC2015 08 27.89065822 01 00.33 +50 50 53.9          15.1 R D0520J95
     WJ2B5AC KC2015 08 27.89189422 01 16.74 +50 50 15.6          15.2 R D0520J95
     WJ2B5AC KC2015 08 29.96986 19 50 05.26 +53 41 58.6          16.3 V      G40
     WJ2B5AC KC2015 08 29.99786 19 52 23.06 +53 42 21.0          16.3 V      G40
     WJ2B5AC KC2015 09 19.86567718 47 00.90 +50 19 26.6          15.9 R D0520J95
     WJ2B5AC KC2015 09 19.86722318 47 09.92 +50 19 55.4          16.0 R D0520J95
     WJ2B5AC KC2015 09 19.86858218 47 17.89 +50 20 20.6          15.9 R D0520J95
     WJ2B5AC  C2015 10 24.08704 17 42 50.41 +46 37 03.3          13.4 VqNEOCP703
     WJ2B5AC  C2015 10 24.09107 17 43 15.65 +46 38 58.4          13.4 VqNEOCP703
     WJ2B5AC  C2015 10 24.09511 17 43 41.19 +46 40 49.9          13.4 VqNEOCP703
     WJ2B5AC  C2015 10 24.09916 17 44 07.12 +46 42 38.1          13.4 VqNEOCP703
     WJ2B5AC  C2015 11 20.08317 18 37 47.56 +50 35 24.6          17.1 V D0539703
     WJ2B5AC  C2015 11 20.08767 18 38 16.88 +50 35 17.1          16.9 V D0539703
     WJ2B5AC  C2015 11 20.09669 18 39 17.23 +50 34 53.2                 D0539703
     WJ2B5AC  C2015 11 20.11541 18 41 29.28 +50 33 29.1          16.9 V D0539703
     WJ2B5AC  C2015 11 20.11615 18 41 34.57 +50 33 24.6          17.1 V D0539703
     WJ2B5AC  C2015 11 20.14045 18 44 40.23 +50 30 35.6          17.1 V D0539703
     WJ2B5AC  C2015 11 20.14066 18 44 41.93 +50 30 33.8          16.9 V D0539703
     WJ2B5AC  C2015 11 20.14108 18 44 45.33 +50 30 30.9          17.1 V D0539703

Station data:
(703) Catalina Sky Survey (N32.41712 W110.73264)  US/Arizona.   Observer R. G.
    Matheny.  Measurers E. J. Christensen, D. C. Fuls, A. R. Gibbs, A. D.
    Grauer, R. E. Hill, J. A. Johnson, R. A. Kowalski, S. M. Larson, R. G.
    Matheny, F. C. Shelly.  0.68-m Schmidt + CCD.
(G40) Slooh.com Canary Islands Observatory (N28.29982 W16.50826)  Canary Islands (Spain).
(H06) iTelescope Observatory, Mayhill (N32.90343 W105.52870)  US/New Mexico.
    Observers E. Guido, G. Sostero, V. Gonano, L. Donato.
(I52) Steward Observatory, Mt. Lemmon Station (N32.44266 W110.78892)  US/Arizona.
      Observer D. C. Fuls.  Measurers E. J. Christensen, D. C. Fuls, A. R.
    Gibbs, A. D. Grauer, R. E. Hill, J. A. Johnson, R. A. Kowalski, S. M.
    Larson, R. G. Matheny, F. C. Shelly.  1.0-m reflector + CCD.
(J95) Great Shefford (N51.47502 W1.44700)  UK.   Observer P. Birtwhistle.
    0.40-m f/6.0 Schmidt-Cassegrain + CCD.
(U69) iTelescope SRO Observatory, Auberry (N37.0705 W119.4130)  US/California.
      Observer B. Lütkenhöner.

Orbital elements:  WJ2B5AC = INTEGRAL = 2002-048A = NORAD 27540 
   Perigee 2015 Aug 1.827363 +/- 0.000663 TT = 19:51:24 (JD 2457236.327363)
Epoch 2015 Aug  1.0 TT; AMR 0.062553 +/- 0.0213 m²/kg        Find_Orb
M 248.04907 +/- 0.08                (J2000 equatorial)
n 135.31051136 +/- 0.000348         Peri.  258.63494 +/- 0.018
a 81105.2839 +/- 0.139              Node   219.10574 +/- 0.012
e   0.8104486 +/- 0.000103          Incl.   53.15620 +/- 0.0018
P   2.66d                  H 28.4   G  0.15   U  7.4
q 15373.6177 +/- 8.34    Q 146836.950 +/- 8.45
34 of 75 observations 2015 June 21-Nov. 20; mean residual 62".177
Residuals in arcseconds: 
150512 703( 343+  201+)   150512 J95( 621+ 21.5+)   150710 J95 28.6- .152+
150512 703( 343+  200+)   150513 J95( 768+  108-)   150710 J95 27.4- .507+
150512 703( 346+  200+)   150513 J95( 770+  109-)   150808 J95 32.9- 11.6-
150512 703( 348+  201+)   150513 J95( 771+  110-)   150808 J95 32.0- 11.7-
150512 I52( 365+  196+)   150516 J95( 225-  421+)   150808 J95 31.1- 11.9-
150512 I52( 366+  197+)   150516 J95( 225-  417+)   150827 J95 51.0+ 1.69-
150512 I52( 366+  197+)   150516 J95( 226-  412+)   150827 J95 50.6+ 1.64-
150512 I52( 371+  195+)   150516 J95( 225-  408+)   150827 J95 50.1+ 1.49-
150512 I52( 370+  195+)   150516 J95( 226-  404+)   150829 G40 26.8+ 13.1+
150512 I52( 372+  196+)   150517 H06( 115+  221+)   150829 G40 38.9+ 14.2+
150512 I52( 376+  195+)   150517 H06( 118+  220+)   150919 J95 79.0+ 23.0+
150512 I52( 375+  194+)   150526 J95( 930+  687-)   150919 J95 79.7+ 23.2+
150512 I52( 376+  195+)   150526 J95( 930+  688-)   150919 J95 80.4+ 23.5+
150512 I52( 375+  194+)   150526 J95( 931+  690-)   151024 703  117-  108-
150512 703( 378+  194+)   150526 J95( 931+  691-)   151024 703  114-  106-
150512 703( 378+  195+)   150526 J95( 931+  692-)   151024 703  112-  104-
150512 703( 378+  195+)   150621 703 77.2+ 56.5+    151024 703  110-  102-
150512 703( 378+  195+)   150621 703 78.9+ 55.3+    151120 703 50.7+ 12.4+
150512 U69( 389+  190+)   150621 703 80.1+ 56.4+    151120 703 51.9+ 13.2+
150512 U69( 390+  190+)   150621 703 82.6+ 57.0+    151120 703 54.7+ 14.6+
150512 U69( 390+  190+)   150621 I52  106+ 60.2+    151120 703 61.9+ 16.7+
150512 U69( 392+  190+)   150621 I52  106+ 60.0+    151120 703 61.1+ 16.5+
150512 J95( 616+ 25.5+)   150621 I52  106+ 60.2+    151120 703 69.2+ 19.2+
150512 J95( 618+ 24.3+)   150621 I52  106+ 60.3+    151120 703 69.6+ 19.2+
150512 J95( 620+ 22.5+)   150710 J95 29.8- .054+    151120 703 70.1+ 19.7+

Ephemerides (geocentric):
Date (UTC) HH   RA              Dec         delta   r     elong  mag
---- -- -- --  ------------   ------------  ------ ------ -----  ---
2015 11 20 15  20 17 57.038   +52 41 30.32  135513 .98814  93.6 16.2
2015 11 20 16  20 25 58.710   +52 40 28.93  133272 .98815  94.7 16.1
2015 11 20 17  20 34 16.942   +52 37 16.66  130802 .98816  95.8 16.0
2015 11 20 18  20 42 53.584   +52 31 38.24  128096 .98816  96.9 15.9
2015 11 20 19  20 51 50.736   +52 23 14.84  125144 .98817  98.1 15.8
2015 11 20 20  21 01 10.810   +52 11 43.12  121937 .98817  99.3 15.7
2015 11 20 21  21 10 56.600   +51 56 33.93  118464 .98818 100.6 15.6
2015 11 20 22  21 21 11.378   +51 37 10.51  114711 .98818 102.0 15.5
2015 11 20 23  21 31 59.025   +51 12 45.93  110662 .98819 103.5 15.4
2015 11 21 00  21 43 24.212   +50 42 19.45  106300 .98819 105.1 15.2
2015 11 21 01  21 55 32.646   +50 04 31.07  101603 .98820 106.9 15.1
2015 11 21 02  22 08 31.446   +49 17 33.26   96545 .98820 108.8 14.9
2015 11 21 03  22 22 29.686   +48 18 57.88   91096 .98820 110.9 14.7
2015 11 21 04  22 37 39.267   +47 05 14.76   85218 .98820 113.3 14.5
2015 11 21 05  22 54 16.339   +45 31 14.66   78866 .98819 116.1 14.2
2015 11 21 06  23 12 43.795   +43 29 01.50   71982 .98819 119.3 13.9
2015 11 21 07  23 33 35.987   +40 45 38.91   64495 .98818 123.2 13.6
2015 11 21 08  23 57 48.581   +36 58 21.32   56314 .98817 128.0 13.2
2015 11 21 09  00 27 02.266   +31 22 48.03   47328 .98815 134.3 12.6
2015 11 21 10  01 04 52.806   +22 19 16.70   37436 .98812 142.6 11.9
2015 11 21 11  02 01 42.550   +05 15 16.71   26755 .98807 150.9 10.9
2015 11 21 12  04 14 15.768   -32 34 36.78   17280 .98797 127.1 10.6
2015 11 21 13  11 29 16.547   -41 22 02.44   18194 .98783  57.8 13??
2015 11 21 14  13 47 44.995   -09 43 43.85   28155 .98772  30.3 18??
2015 11 21 15  14 36 48.207   +06 13 01.19   38767 .98766  31.2 18??
2015 11 21 16  15 06 07.981   +15 22 37.32   48538 .98761  36.6 18??
2015 11 21 17  15 27 21.259   +21 25 52.83   57412 .98757  41.6 17??
2015 11 21 18  15 44 13.449   +25 48 28.62   65497 .98755  45.7 17??
2015 11 21 19  15 58 23.918   +29 09 56.88   72901 .98752  49.2 17??
2015 11 21 20  16 10 44.922   +31 51 07.50   79712 .98751  52.1 17??
2015 11 21 21  16 21 47.274   +34 04 05.89   85999 .98749  54.6 17??
2015 11 21 22  16 31 50.662   +35 56 24.63   91819 .98748  56.9 17??
2015 11 21 23  16 41 08.442   +37 33 02.25   97215 .98747  58.9 17??
2015 11 22 00  16 49 50.108   +38 57 24.55  102225 .98747  60.7 17.3
2015 11 22 01  16 58 02.662   +40 11 58.59  106877 .98746  62.4 17.3
2015 11 22 02  17 05 51.430   +41 18 32.55  111198 .98746  63.9 17.3
2015 11 22 03  17 13 20.573   +42 18 27.99  115207 .98745  65.3 17.3
2015 11 22 04  17 20 33.414   +43 12 47.71  118924 .98745  66.7 17.2
2015 11 22 05  17 27 32.661   +44 02 20.89  122362 .98745  67.9 17.2
2015 11 22 06  17 34 20.561   +44 47 46.65  125535 .98745  69.1 17.2
2015 11 22 07  17 40 59.009   +45 29 36.51  128455 .98745  70.3 17.2
2015 11 22 08  17 47 29.631   +46 08 16.12  131130 .98745  71.4 17.2
2015 11 22 09  17 53 53.838   +46 44 06.58  133571 .98745  72.5 17.1
2015 11 22 10  18 00 12.876   +47 17 25.34  135783 .98746  73.5 17.1
2015 11 22 11  18 06 27.858   +47 48 26.94  137773 .98746  74.5 17.1
2015 11 22 12  18 12 39.794   +48 17 23.55  139548 .98746  75.5 17.1
2015 11 22 13  18 18 49.608   +48 44 25.36  141111 .98747  76.4 17.0
2015 11 22 14  18 24 58.164   +49 09 40.92  142466 .98747  77.3 17.0
2015 11 22 15  18 31 06.271   +49 33 17.36  143618 .98748  78.2 17.0
2015 11 22 16  18 37 14.705   +49 55 20.63  144569 .98748  79.1 16.9
2015 11 22 17  18 43 24.213   +50 15 55.60  145321 .98749  80.0 16.9
2015 11 22 18  18 49 35.526   +50 35 06.20  145875 .98749  80.9 16.9
2015 11 22 19  18 55 49.366   +50 52 55.50  146235 .98750  81.8 16.8
2015 11 22 20  19 02 06.458   +51 09 25.79  146399 .98751  82.7 16.8
2015 11 22 21  19 08 27.533   +51 24 38.58  146369 .98751  83.5 16.8
2015 11 22 22  19 14 53.337   +51 38 34.67  146144 .98752  84.4 16.7
2015 11 22 23  19 21 24.644   +51 51 14.09  145724 .98753  85.3 16.7
2015 11 23 00  19 28 02.255   +52 02 36.15  145108 .98753  86.2 16.6
2015 11 23 01  19 34 47.017   +52 12 39.38  144295 .98754  87.0 16.6
2015 11 23 02  19 41 39.825   +52 21 21.43  143282 .98755  87.9 16.5