"Pseudo-MPEC" for S509559 = probable Vela

Created 2017 May 7 16:16:39 UT using Find_Orb

Click here for a plot of perigee and inclination vs. time for this object, running back to 1965. I did this in hopes of identifying the object. I am reasonably certain that it's either 1970-027A (Vela 6A) or 1970-027B (Vela 6B) or 1969-046D (Vela 5A). But the orbits for all three were somewhat similar (especially the first two, which came from the same launch). The perigee and inclination of S509559 back then match nicely, confirming it should be one of those three. But I've no idea which one.

Space-Track provided TLEs for all three objects at various times. I have TLEs for the 1970 objects for an epoch in 2017 June, and for 1969-046D for various epochs up to 2017 January. None of them match at all. I don't know for sure, of course, and Space-Track is not forthcoming in such matters. But I am willing to bet that at some point in 2017, they realized their TLEs for all three objects were bogus and dropped them.

Astrometry:
S509559       C2016 04 28.35557 13 55 16.234-03 49 46.64                     F51
S509559       C2016 04 28.38911 13 58 32.165-04 07 25.02                     F51
S509559       C2016 05 10.90022 10 26 58.69 +09 27 56.5          15.4 R D0545Y00
S509559       C2016 05 10.90106 10 27 04.34 +09 27 33.8          15.7 R D0545Y00
S509559       C2016 05 10.90215 10 27 11.66 +09 27 03.1          15.5 R D0545Y00
S509559       C2016 05 10.94504 10 31 48.71 +09 07 24.6          15.4 R D0545Y00
S509559       C2016 05 10.94695 10 32 01.26 +09 06 29.0          15.5 R D0545Y00
S509559       C2016 05 10.94797 10 32 07.63 +09 06 00.9          15.5 R D0545Y00
S509559       C2016 05 10.94883 10 32 13.06 +09 05 37.1          15.0 R D0545Y00
S509559       C2016 05 10.94990 10 32 20.08 +09 05 05.8          15.3 R D0545Y00
S509559       C2016 05 10.95088 10 32 26.31 +09 04 36.5          15.4 R D0545Y00
S509559       C2016 05 11.01596 10 39 26.32 +08 32 20.5          16.0 R D0545Y00
S509559       C2016 05 11.01652 10 39 30.35 +08 32 01.7          15.9 R D0545Y00
S509559       C2016 05 11.01787 10 39 39.21 +08 31 19.5          16.1 R D0545Y00
S509559       C2016 05 11.01824 10 39 41.69 +08 31 07.9          16.2 R D0545Y00
S509559       C2016 05 11.01901 10 39 46.57 +08 30 45.3          15.9 R D0545Y00
S509559       C2016 05 11.02019 10 39 54.61 +08 30 07.8          15.8 R D0545Y00
S509559       C2016 05 11.24028 11 11 55.61 +04 50 01.8          18.8 R D0545926
S509559       C2016 05 11.24032 11 11 55.84 +04 50 00.5          19.4 R D0545926
S509559       C2016 05 11.24067 11 11 58.12 +04 49 51.2          18.9 R D0545926
S509559       C2016 05 11.24108 11 12 00.59 +04 49 39.6          19.4 R D0545926
S509559       C2016 05 11.24162 11 12 03.99 +04 49 24.5          19.5 R D0545926
S509559       C2016 05 11.24291 11 12 12.18 +04 48 48.3          19.4 R D0545926
S509559       C2016 05 11.24420 11 12 20.29 +04 48 12.6          19.2 R D0545926
S509559       C2016 05 11.24550 11 12 28.49 +04 47 35.8          19.1 R D0545926
S509559       C2016 05 11.24578 11 12 30.27 +04 47 28.2          18.8 R D0545926
S509559       C2016 05 11.24618 11 12 32.87 +04 47 16.7          19.5 R D0545926
S509559       C2016 05 11.24659 11 12 35.44 +04 47 05.4          20.1 R D0545926
S509559       C2016 05 11.24679 11 12 36.73 +04 46 59.6          19.3 R D0545926
S509559       C2016 05 11.30538 11 19 03.90 +04 19 30.0          19.4 R D0545926
S509559       C2016 05 11.30667 11 19 12.90 +04 18 52.6          19.1 R D0545926
S509559       C2016 05 11.30796 11 19 21.84 +04 18 15.6          19.2 R D0545926
S509559      KC2016 05 12.10542513 05 30.622-00 09 03.24         19.0 R D0546Y28
S509559      KC2016 05 12.10788313 05 43.889-00 10 12.75         19.3 R D0546Y28
S509559       C2017 03 26.36609 12 27 29.02 +01 54 59.9          19.2 V D0555G96
S509559       C2017 03 26.36632 12 27 30.21 +01 54 52.8          19.3 V D0555G96
S509559       C2017 03 26.36655 12 27 31.37 +01 54 46.2          19.2 V D0555G96
S509559       C2017 03 26.36678 12 27 32.54 +01 54 39.3          19.2 V D0555G96

Station data:
(926) Tenagra II  (N31.462040 W110.879100)  US/Arizona.
   Observers M. Schwartz, P. R. Holvorcem. Measurer M. Schwartz. 0.81-m f/7
   Ritchey-Chrétien + CCD.
(F51) Pan-STARRS 1, Haleakala  (N20.707234 W156.255910)  US/Hawaii.
   Observers N. Primak, A. Schultz, S. Watters, J. Thiel, T. Goggia. Measurer
   PS1 Science Consortium. 1.8-m Ritchey-Chrétien + CCD.
(G96) Mt. Lemmon Survey  (N32.442751 W110.788720)  US/Arizona.  Observers E.
   J. Christensen, A. R. Gibbs, A. D. Grauer, R. E. Hill, J. A. Johnson, R.
   A. Kowalski, S. M. Larson, F. C. Shelly. 1.5-m reflector + CCD.
(Y00) SONEAR Observatory, Oliveira  (S20.715080 W44.784960)  Brazil.
   Observers C. Jacques, E. Pimentel, J. Barros. Measurer C. Jacques. 0.28-m
   f/2.2 astrograph + CCD.
(Y28) OASI, Nova Itacuruba  (S8.788707 W38.687400)  Brazil.  Observers F.
   Monteiro, H. Medeiros, D. Lazzaro, J. S. Silva, R. Souza, T. Rodrigues.
   Measurers M. Micheli, F. Monteiro. 1.0-m f/7 reflector + CCD.

Orbital elements:  S509559 = probable Vela
   Perigee 2017 Mar 24.261932 +/- 0.000244 TT =  6:17:10 (JD 2457836.761932)
Epoch 2017 Mar 26.0 TT; AMR 0.00029528 +/- 0.00282 m2/kg     Gray
M 133.3784154 +/- 0.018             (J2000 equatorial)
n  76.7394560276 +/- 5.4e-5         Peri.  355.7373644 +/- 0.010
a118374.37398 +/- 0.0555            Node    19.0395247 +/- 0.0030
e   0.460798923 +/- 8.38e-6         Incl.   14.5790313 +/- 0.0008
P6755.20m/4.691d           H 30.9   G  0.15   U  6.2
q 63827.589893 +/- 0.964    Q 172921.15807 +/- 1.07
From 38 observations 2016 Apr. 28-2017 Mar. 26; mean residual 1".587
Residuals in arcseconds: 
160428 F51 3.53+ 1.41-    160511 Y00 1.67+ .500-    160511 926 .132- .173+
160428 F51 3.24- 2.06+    160511 Y00 2.27+ .717-    160511 926 .563- .352+
160510 Y00 1.94+ 1.31-    160511 Y00 .679- .383+    160511 926 .237- .152+
160510 Y00 3.68+ 1.67-    160511 Y00 3.02+ .771-    160511 926 2.11- 1.00+
160510 Y00 5.87+ 3.33-    160511 926 .237- .263+    160511 926 .968- .051+
160510 Y00 4.06- 1.24+    160511 926 .561- .081+    160511 926 1.00- .495-
160510 Y00 .527+ .068+    160511 926 .596+ .561+    160512 Y28 .838+ .582+
160510 Y00 1.91- 1.09+    160511 926 1.07- .419+    160512 Y28 .978+ .471+
160510 Y00 3.08- 1.88+    160511 926 1.10- .412+    170326 G96 .161- .368-
160510 Y00 .608- 1.21+    160511 926 .280- .279+    170326 G96 .037+ .619-
160510 Y00 1.29- 6.9m+    160511 926 .852- .662+    170326 G96 .217- .370-
160511 Y00 2.95- 1.79+    160511 926 1.22- .239+    170326 G96 .325- .420-
160511 Y00 2.16+ .194+    160511 926 1.12- .476+

Ephemerides (geocentric):
Date (UTC) HH   RA              Dec         delta   r     elong  mag " sig PA
---- -- -- --  ------------   ------------  ------ ------ -----  --- ---- ---
2017 03 26 00  11 41 45.737   +05 56 43.04  164428 0.9986 167.6 16.9   33 103
2017 03 26 01  11 47 28.465   +05 36 23.67  165561 0.9986 168.9 16.8   32 103
2017 03 26 02  11 53 06.303   +05 16 08.08  166612 0.9987 170.1 16.8   32 103
2017 03 26 03  11 58 39.700   +04 55 55.96  167582 0.9987 171.2 16.8   31 103
2017 03 26 04  12 04 09.080   +04 35 46.99  168470 0.9987 172.2 16.7   30 103
2017 03 26 05  12 09 34.847   +04 15 40.82  169277 0.9987 173.0 16.7   29 103
2017 03 26 06  12 14 57.385   +03 55 37.08  170004 0.9987 173.7 16.7   28 104
2017 03 26 07  12 20 17.063   +03 35 35.36  170651 0.9988 174.2 16.7   28 104
2017 03 26 08  12 25 34.236   +03 15 35.26  171217 0.9988 174.4 16.7   27 104
2017 03 26 09  12 30 49.245   +02 55 36.36  171703 0.9988 174.2 16.7   26 104
2017 03 26 10  12 36 02.423   +02 35 38.21  172110 0.9988 173.8 16.7   25 104
2017 03 26 11  12 41 14.092   +02 15 40.36  172437 0.9988 173.2 16.7   24 104
2017 03 26 12  12 46 24.569   +01 55 42.35  172685 0.9988 172.4 16.8   23 104
2017 03 26 13  12 51 34.165   +01 35 43.72  172853 0.9988 171.5 16.8   23 104
2017 03 26 14  12 56 43.186   +01 15 43.98  172942 0.9988 170.5 16.9   22 104
2017 03 26 15  13 01 51.938   +00 55 42.65  172952 0.9989 169.4 16.9   21 104
2017 03 26 16  13 07 00.723   +00 35 39.25  172882 0.9989 168.3 16.9   20 104
2017 03 26 17  13 12 09.846   +00 15 33.26  172733 0.9989 167.2 17.0   19 104
2017 03 26 18  13 17 19.613   -00 04 35.81  172504 0.9989 166.0 17.0   18 105
2017 03 26 19  13 22 30.332   -00 24 48.47  172196 0.9989 164.8 17.1   17 105
2017 03 26 20  13 27 42.318   -00 45 05.25  171809 0.9989 163.6 17.1   17 105
2017 03 26 21  13 32 55.890   -01 05 26.66  171341 0.9989 162.4 17.1   16 105
2017 03 26 22  13 38 11.378   -01 25 53.23  170794 0.9989 161.1 17.2   15 105
2017 03 26 23  13 43 29.119   -01 46 25.50  170166 0.9989 159.9 17.2   14 105
2017 03 27 00  13 48 49.463   -02 07 03.98  169458 0.9989 158.6 17.2   13 105
2017 03 27 01  13 54 12.773   -02 27 49.22  168669 0.9989 157.3 17.3   12 105
2017 03 27 02  13 59 39.429   -02 48 41.76  167799 0.9989 156.0 17.3   11 105
2017 03 27 03  14 05 09.825   -03 09 42.12  166847 0.9989 154.6 17.3   10 105
2017 03 27 04  14 10 44.379   -03 30 50.83  165814 0.9989 153.3 17.3    9 105
2017 03 27 05  14 16 23.532   -03 52 08.42  164698 0.9989 151.9 17.4  8.5 105
2017 03 27 06  14 22 07.749   -04 13 35.40  163500 0.9988 150.5 17.4  7.5 105
2017 03 27 07  14 27 57.525   -04 35 12.27  162219 0.9988 149.0 17.4  6.4 106
2017 03 27 08  14 33 53.390   -04 56 59.49  160854 0.9988 147.6 17.4  5.3 106
2017 03 27 09  14 39 55.908   -05 18 57.52  159405 0.9988 146.1 17.5  4.2 107
2017 03 27 10  14 46 05.689   -05 41 06.77  157872 0.9988 144.6 17.5  3.1 108
2017 03 27 11  14 52 23.388   -06 03 27.59  156254 0.9988 143.0 17.5  1.9 112
2017 03 27 12  14 58 49.712   -06 26 00.29  154550 0.9988 141.5 17.5  0.8 126
2017 03 27 13  15 05 25.431   -06 48 45.07  152760 0.9988 139.8 17.5  0.6  71
2017 03 27 14  15 12 11.381   -07 11 42.05  150883 0.9987 138.2 17.6  1.8  92
2017 03 27 15  15 19 08.475   -07 34 51.23  148920 0.9987 136.5 17.6  3.1  96
2017 03 27 16  15 26 17.713   -07 58 12.41  146868 0.9987 134.7 17.6  4.5  97
2017 03 27 17  15 33 40.191   -08 21 45.22  144729 0.9987 132.9 17.6  5.9  98
2017 03 27 18  15 41 17.119   -08 45 29.03  142502 0.9987 131.0 17.6  7.3  98
2017 03 27 19  15 49 09.832   -09 09 22.87  140186 0.9986 129.1 17.7  8.8  98
2017 03 27 20  15 57 19.808   -09 33 25.38  137782 0.9986 127.1 17.7   10  98
2017 03 27 21  16 05 48.691   -09 57 34.69  135289 0.9986 125.1 17.7   12  98
2017 03 27 22  16 14 38.311   -10 21 48.31  132707 0.9986 122.9 17.7   13  98
2017 03 27 23  16 23 50.712   -10 46 02.95  130037 0.9985 120.7 17.7   15  98
2017 03 28 00  16 33 28.182   -11 10 14.31  127280 0.9985 118.3 17.8   17  98
2017 03 28 01  16 43 33.289   -11 34 16.83  124436 0.9985 115.9 17.8   19  97
2017 03 28 02  16 54 08.921   -11 58 03.40  121508 0.9985 113.3 17.8   21  97
2017 03 28 03  17 05 18.331   -12 21 24.89  118496 0.9984 110.6 17.8   23  96
2017 03 28 04  17 17 05.188   -12 44 09.66  115405 0.9984 107.8 17.9   25  96
2017 03 28 05  17 29 33.629   -13 06 02.89  112238 0.9984 104.8 17.9   27  95
2017 03 28 06  17 42 48.326   -13 26 45.79  109000 0.9983 101.6 18.0   29  94
2017 03 28 07  17 56 54.537   -13 45 54.52  105697 0.9983  98.2 18.0   32  94
2017 03 28 08  18 11 58.167   -14 02 58.93  102337 0.9983  94.6 18.1   34  93
2017 03 28 09  18 28 05.811   -14 17 21.06   98931 0.9982  90.7 18.2   37  92
2017 03 28 10  18 45 24.775   -14 28 13.26   95492 0.9982  86.6 18.3   39  91
2017 03 28 11  19 04 03.043   -14 34 36.21   92037 0.9982  82.2 18.4   42  90