"Pseudo-MPEC" for ZTF00pm = ZTF01Ls

Created 2018 Sep 21 15:41:13 UT using Find_Orb

Click here for an explanation of pseudo-MPECs

TLEs are available for this object, and for some of the other objects on these pages. Be warned that, for reasons discussed below, the TLEs for this particular object may not be all that good.

This is an ETBO ("Empty Trash Bag Object"), so called because it has roughly the size and mass of an empty trash bag. As a result, it tends to get kicked around a lot by solar radiation pressure, and its future motions are unpredictable, much like an empty trash bag being blown down a street : you have a general idea that it will go downwind, but the specifics are unknown.

When ZTF00pm was initially found by the Zwicky Transient Facility, I suspected it of being an artificial satellite. An SSTO (super-synchronous transfer orbit) fit reasonably well. However, I couldn't conclusively say one way or another. I made a note of its orbital elements and hoped a similar object would eventually turn up.

And six days later, it did, in the form of ZTF01Ls. That object was only observed for about three minutes, though, and I couldn't be entirely certain the linkage was correct. Normally, under such circumstances, I'd ask Peter Birtwhistle at Great Shefford to try to recover it. It often happens that when data for a new artsat (or rock) appears on NEOCP, nightfall has arrived in the UK and Peter is nicely placed to follow it up. In this case, though, the object would have been faint, fast, and low in the sky for Peter, and about to set. So I had to give up on that possibility.

Instead, I sent ephemerides to Ye Quanzhi at PTF, suggesting the object might show up that night in PTF data. Quanzhi pointed out that it might well have appeared in the nights in between, and did a check for the previous night. Almost immediately, he found the two positions shown below for 2018 September 16, confirming that the linkage was real.

 
 Astrometry: 
     ZTF00pm  C2018 09 11.34519 23 54 53.50 +07 15 26.8                UNEOCPI41
     ZTF00pm  C2018 09 11.34553 23 54 57.05 +07 15 16.2                UNEOCPI41
     ZTF00pm  C2018 09 11.36857 23 58 58.01 +07 03 26.8                UNEOCPI41
     ZTF00pm  C2018 09 11.36892 23 59 01.68 +07 03 15.4                UNEOCPI41
     ZTF00pm  C2018 09 11.36947 23 59 07.64 +07 02 57.3          17.67RUNEOCPI41
     ZTF00pm  C2018 09 11.36981 23 59 11.31 +07 02 45.9          17.67RUNEOCPI41
     ZTF01Ls tC2018 09 16.41534 00 44 01.49 +04 48 52.4          17.46RU     I41
     ZTF01Ls tC2018 09 16.41569 00 44 07.24 +04 48 27.2          17.46RU     I41
     ZTF01Ls tC2018 09 17.31735723 22 22.01 +08 01 04.7          18.40gUNEOCPI41
     ZTF01Ls tC2018 09 17.31770423 22 24.96 +08 00 59.0          18.40gUNEOCPI41
     ZTF01Ls tC2018 09 17.31918323 22 37.52 +08 00 31.9          18.69gUNEOCPI41
     ZTF01Ls tC2018 09 17.31953023 22 40.57 +08 00 25.6          18.69gUNEOCPI41

Station data:
(I41) Palomar Mountain--ZTF  (N33.357340 W116.859780)  US/California.
   Observer A. U. Tomatic. Measurer Q.-Z. Ye.

Orbital elements:  ZTF00pm = ZTF01Ls
   Perigee 2018 Sep 14.222944 +/- 0.000373 TT =  5:21:02 (JD 2458375.722944)
Epoch 2018 Sep 14.0 TT; AMR 27.978 +/- 0.19 m2/kg            Gray
M 294.483711 +/- 0.10               (J2000 equator)
n 293.868186151 +/- 0.00128         Peri.  291.267046 +/- 0.019
a 48361.72590 +/- 0.14              Node   236.661128 +/- 0.0031
e   0.79585323 +/- 0.000224         Incl.   10.766045 +/- 0.0037
P1764.02m/1.225d           H 33.9   G  0.15   U  8.3
q 9872.890051 +/- 10.9    Q 86850.56174 +/- 10.6
From 12 observations 2018 Sept. 11-17; mean residual 1".058
Residuals in arcseconds: 
180911 I41 2.47- .555+    180911 I41 1.24+ .477-    180917 I41 1.52+ 1.10-
180911 I41 1.43- .318-    180911 I41 1.65+ .596-    180917 I41 .978+ .299-
180911 I41 1.21+ .729-    180916 I41 .779+ .176-    180917 I41 1.61- .482+
180911 I41 .139+ .578-    180916 I41 1.36- .418+    180917 I41 .699- .762+

Ephemerides (geocentric):
Date (UTC) HH   RA              Dec         delta  elong  mag " sig PA
---- -- -- --  -------------   -----------  ------ -----  --- ---- ---
2018 09 17 00  22 03 39.811   +10 48 07.83   72906 153.2 18.6 83.8  95
2018 09 17 01  22 16 17.819   +10 43 37.25   76745 155.9 18.6 65.4  96
2018 09 17 02  22 27 49.208   +10 37 49.31   79911 158.3 18.6 50.6  97
2018 09 17 03  22 38 32.485   +10 30 59.46   82449 160.4 18.6 38.4  98
2018 09 17 04  22 48 41.245   +10 23 15.72   84393 162.3 18.6 28.0 100
2018 09 17 05  22 58 26.052   +10 14 41.37   85765 164.0 18.6 19.1 101
2018 09 17 06  23 07 55.597   +10 05 16.30   86583 165.5 18.6 11.5 104
2018 09 17 07  23 17 17.473   +09 54 57.55   86854 166.7 18.5 4.79 112
2018 09 17 08  23 26 38.756   +09 43 39.55   86583 167.6 18.5 1.57  60
2018 09 17 09  23 36 06.495   +09 31 13.82   85766 168.1 18.4 6.33  92
2018 09 17 10  23 45 48.201   +09 17 28.38   84394 168.3 18.4 10.6  97
2018 09 17 11  23 55 52.414   +09 02 06.62   82451 167.9 18.4 14.0  99
2018 09 17 12  00 06 29.458   +08 44 45.50   79914 167.0 18.3 16.4 102
2018 09 17 13  00 17 52.572   +08 24 52.37   76749 165.6 18.3 17.5 104
2018 09 17 14  00 30 19.715   +08 01 39.66   72912 163.7 18.2 16.9 107
2018 09 17 15  00 44 16.746   +07 33 55.20   68341 161.1 18.2 13.7 113
2018 09 17 16  01 00 23.434   +06 59 43.36   62951 157.9 18.1 6.98 139
2018 09 17 17  01 19 46.047   +06 15 45.10   56626 153.7 18.0 12.2  71
2018 09 17 18  01 44 27.309   +05 15 41.96   49191 148.0 17.9 44.5  91
2018 09 17 19  02 18 51.940   +03 45 42.92   40385 139.9 17.7  119  96
2018 09 17 20  03 15 11.881   +01 07 45.22   29795 126.2 17.4  336  99
2018 09 17 21  05 28 16.998   -05 04 05.43   17022  93.2 17.2 1431  99
2018 09 17 22  14 08 29.168   -04 13 20.16   11253  37.5 20?? 4220  80
2018 09 17 23  18 30 12.965   +07 28 28.21   24018 102.0 17.7 1036  83
2018 09 18 00  19 50 52.003   +09 44 49.84   35635 121.5 17.9  487  86
2018 09 18 01  20 34 18.522   +10 29 16.22   45221 131.9 18.1  300  89
2018 09 18 02  21 03 32.986   +10 46 43.23   53263 138.8 18.3  208  91
2018 09 18 03  21 25 37.125   +10 53 03.67   60085 143.9 18.4  154  92
2018 09 18 04  21 43 28.783   +10 53 50.73   65898 147.9 18.5  117  94
2018 09 18 05  21 58 38.214   +10 51 27.07   70842 151.3 18.6 90.6  95
2018 09 18 06  22 11 57.183   +10 47 01.93   75015 154.3 18.6 70.4  96
2018 09 18 07  22 23 58.155   +10 41 11.58   78489 156.9 18.6 54.3  97
2018 09 18 08  22 35 02.982   +10 34 15.65   81316 159.2 18.6 41.2  98
2018 09 18 09  22 45 27.295   +10 26 24.57   83534 161.2 18.6 30.1 100
2018 09 18 10  22 55 22.925   +10 17 43.11   85171 163.1 18.6 20.7 102
2018 09 18 11  23 04 59.340   +10 08 12.22   86246 164.8 18.6 12.6 105
2018 09 18 12  23 14 24.583   +09 57 49.89   86772 166.2 18.5 5.57 113
2018 09 18 13  23 23 45.919   +09 46 31.46   86755 167.4 18.5 1.54  42
2018 09 18 14  23 33 10.360   +09 34 09.54   86194 168.3 18.4 6.38  89
2018 09 18 15  23 42 45.148   +09 20 33.58   85083 168.8 18.4 11.0  95