"Pseudo-MPEC" for ZTF00V9 = ZTF00Vv = ZTF00Y5

Created 2018 Sep 8 20:03:38 UT using Find_Orb

Click here for an explanation of pseudo-MPECs

TLEs are available for this and 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 Zwicky Transient Facility object was found first as ZTF00V9, then recovered two days (and two orbits) later as ZTF00Vv. The orbital elements matched well enough to make the linkage "obvious", but a straightforward linkage resulted in mean residuals of 103 arcseconds.

Including solar radiation pressure got a much more reasonable orbit, with a truly huge area/mass ratio of about 95 m^2/kg. If the object really is about a meter across, as its brightness suggests, it would have a mass of about ten grams. It could be a piece of insulation, for example.

The object was found a third time on 2018 September 2, with further data six days later from Marco Micheli at (J04) in Tenerife. As shown below, you can't really fit all the arcs, though they fit pairwise nicely. There are almost certainly some "sideways" forces, and inconsistent area presented to the sun, that are not being modeled here. The exact value depends on which arcs you use, but the area/mass ratio is still somewhere around 90 m^2/kg.

Deepening the mystery, ZTF found ZTF00Y9 = ZTF00Yp = ZTF00ah and ZTF00hf = ZTF00YB at roughly the same time, and they're also small, lightweight bits in roughly one-day orbits.

Predicting the path of this object is a bit like trying to predict where a plastic bag will go when it's being blown down the street. You know it'll mostly go with the wind, but it'll do some unpredictable moves as well. (Which is why I'm now referring to these objects as "ETBOs", for "Empty Trash Bag Objects". As of 21 September, ZTF has found four of them, with area/mass ratios of about 20 to 100 m^2/kg.) So don't take the ephemerides or TLEs too seriously. Not only are there probably significant errors; I don't even have a way to evaluate how great those errors might be (could be arcseconds, could be several degrees).

It may also be significant that this object was stumbled upon three times over the last few weeks. It suggests it hasn't been up for all that long. It would certainly seem strange if an object had been orbiting for years on end, unnoticed, and then just happened to get picked up three times in two weeks.

 
 Astrometry: 
     ZTF00V9  C2018 08 19.31259 22 31 35.41 +00 58 34.9                UNEOCPI41
     ZTF00V9  C2018 08 19.31293 22 31 39.87 +00 59 01.2                UNEOCPI41
     ZTF00V9  C2018 08 19.35747 22 41 45.04 +01 55 58.5          18.69gUNEOCPI41
     ZTF00V9  C2018 08 19.35781 22 41 49.64 +01 56 24.4          18.69gUNEOCPI41
     ZTF00V9  C2018 08 19.37902 22 46 47.70 +02 23 14.9                UNEOCPI41
     ZTF00V9  C2018 08 19.37936 22 46 52.49 +02 23 39.3                UNEOCPI41
     ZTF00Vv  C2018 08 21.37456 22 55 51.13 +02 53 10.2                UNEOCPI41
     ZTF00Vv  C2018 08 21.37491 22 55 56.12 +02 53 35.6                UNEOCPI41
     ZTF00Vv  C2018 08 21.40331 23 03 00.64 +03 27 26.0          18.87gUNEOCPI41
     ZTF00Vv  C2018 08 21.40366 23 03 06.06 +03 27 52.2          18.87gUNEOCPI41
     ZTF00Vv  C2018 08 21.40518 23 03 29.58 +03 29 39.1          18.52gUNEOCPI41
     ZTF00Vv  C2018 08 21.40553 23 03 34.93 +03 30 05.3          18.52gUNEOCPI41
     ZTF00Y5  C2018 09 02.27366 23 33 18.90 +04 03 01.5         x17.32RUNEOCPI41
     ZTF00Y5  C2018 09 02.27400 23 33 24.24 +04 03 18.5         x17.32RUNEOCPI41
     ZTF00Y5  C2018 09 02.27517 23 33 41.86 +04 04 17.0         x17.09RUNEOCPI41
     ZTF00Y5  C2018 09 02.27552 23 33 46.87 +04 04 34.0         x17.09RUNEOCPI41
     ZTF00Y5 FC2018 09 02.36535 23 58 01.77 +05 15 25.4         x            I41
     ZTF00Y5 FC2018 09 02.36569 23 58 08.06 +05 15 42.2         x            I41
     ZTF00Yq  C2018 09 04.30934 23 53 14.51 +04 50 40.8 FixDup  x17.83gUNEOCPI41
     ZTF00Yq  C2018 09 04.30934 23 53 14.51 +04 50 40.8 Duplicat!17.83gUNEOCPI41
     ZTF00Yq  C2018 09 04.30969 23 53 20.47 +04 50 58.0         x17.83gUNEOCPI41
     ZTF00Yq  C2018 09 04.35109 00 05 11.80 +05 19 56.1         x17.23RUNEOCPI41
     ZTF00Y5  C2018 09 08.23516823 26 16.412+04 51 47.41         17.0 GV     J04
     ZTF00Y5  C2018 09 08.23524323 26 17.630+04 51 49.99         17.1 GV     J04
     ZTF00Y5  C2018 09 08.23531523 26 18.770+04 51 52.16         17.1 GV     J04
     ZTF00Y5  C2018 09 08.23538623 26 19.984+04 51 53.71         17.0 GV     J04
     ZTF00Y5  C2018 09 08.23545623 26 21.106+04 51 56.08         17.1 GV     J04
     ZTF00Y5  C2018 09 08.23559723 26 23.414+04 51 59.90         17.1 GV     J04
     ZTF00Y5  C2018 09 08.23566823 26 24.556+04 52 02.16         17.2 GV     J04
     ZTF00Y5  C2018 09 08.23573823 26 25.704+04 52 04.69         17.0 GV     J04
     ZTF00Y5  C2018 09 08.23580823 26 26.843+04 52 06.33         17.1 GV     J04
     ZTF00Y5  C2018 09 08.23587923 26 28.000+04 52 07.80         17.0 GV     J04
     ZTF00Y5  C2018 09 08.23594923 26 29.124+04 52 09.68         17.1 GV     J04

Station data:
(I41) Palomar Mountain--ZTF  (N33.357340 W116.859780)  US/California.
   Observer A. U. Tomatic. Measurer Q.-Z. Ye.
(J04) ESA Optical Ground Station, Tenerife  (N28.300924 W16.511830)  Canary
   Islands (Spain).  Observer D. Abreu. Measurers M. Micheli, D. Koschny, A.
   Knöfel, E. Schwab, M. Busch. 1.0-m f/4.4 reflector + CCD.

Orbital elements:  ZTF00V9 = ZTF00Vv = ZTF00Y5
   Perigee 2018 Sep 7.664998 +/- 0.00838 TT = 15:57:35 (JD 2458369.164998)
Epoch 2018 Sep  8.0 TT; AMR 106.86 +/- 2.68 m2/kg            Gray
M 121.438708 +/- 3.0                (J2000 equator)
n 362.501110446 +/- 0.0548          Peri.  220.040294 +/- 0.8
a 42046.57372 +/- 4.24              Node   310.628383 +/- 0.25
e   0.78617234 +/- 0.000769         Incl.    9.900860 +/- 0.14
P1430.04m/0.993d           H 33.6   G  0.15   U 10.8
q 8990.720276 +/- 31.5    Q 75102.42718 +/- 39.3
23 of 33 observations 2018 Aug. 19-Sept. 8; mean residual 17".001
Residuals in arcseconds: 
180819 I41 16.2- 7.18+    180821 I41 7.93- 4.19+    180908 J04 9.47- 3.36-
180819 I41 16.9- 7.29+    180902 I41( 565+ 83.9+)   180908 J04 7.48- 2.49-
180819 I41 16.8+ 7.60-    180902 I41( 576+ 85.5+)   180908 J04 6.01- 1.96-
180819 I41 14.8+ 7.94-    180902 I41( 602+ 91.1+)   180908 J04 3.22- 2.02-
180819 I41 36.6- 36.8-    180902 I41( 606+ 92.3+)   180908 J04 1.60- 1.25-
180819 I41 38.8- 38.7-    180902 I41(3255+  548+)   180908 J04 2.39+ .631-
180821 I41 44.3+ 29.5+    180902 I41(3271+  552+)   180908 J04 4.09+ .016+
180821 I41 42.9+ 29.6+    180904 I41(2208+  301+)   180908 J04 6.10+ .956+
180821 I41 .373- 5.68+    180904 I41(2208+  301+)   180908 J04 7.97+ 1.01+
180821 I41 1.13- 6.53+    180904 I41(2223+  305+)   180908 J04 9.89+ .865+
180821 I41 5.67- 3.35+    180904 I41(3881+  542+)   180908 J04 11.5+ 1.16+

Ephemerides (geocentric):
Date (UTC) HH   RA              Dec         delta  elong  mag " sig PA
---- -- -- --  -------------   -----------  ------ -----  --- ---- ---
2018 09 08 00  22 33 44.998   +04 39 13.90   69629 166.9 17.8  518  92
2018 09 08 01  22 46 46.183   +05 08 39.86   72131 168.1 17.8  395  93
2018 09 08 02  22 59 03.826   +05 35 26.72   73866 168.4 17.8  319  94
2018 09 08 03  23 10 55.645   +06 00 16.86   74866 168.1 17.9  279  92
2018 09 08 04  23 22 36.352   +06 23 41.76   75147 167.1 17.9  273  89
2018 09 08 05  23 34 19.429   +06 46 06.05   74713 165.5 18.0  299  86
2018 09 08 06  23 46 18.576   +07 07 49.94   73559 163.6 18.0  360  83
2018 09 08 07  23 58 49.208   +07 29 10.81   71663 161.3 18.0  463  81
2018 09 08 08  00 12 10.411   +07 50 24.14   68990 158.6 18.0  620  81
2018 09 08 09  00 26 48.030   +08 11 43.72   65488 155.6 18.0  853  81
2018 09 08 10  00 43 20.212   +08 33 20.39   61079 151.9 18.0 1202  81
2018 09 08 11  01 02 48.683   +08 55 16.86   55649 147.5 17.9 1750  83
2018 09 08 12  01 27 04.961   +09 17 08.92   49026 142.0 17.8 2684  84
2018 09 08 13  02 00 03.138   +09 36 49.88   40944 134.2 17.6 4512  86
2018 09 08 14  02 52 05.289   +09 43 50.76   30957 121.9 17.3 9158  89
2018 09 08 15  04 46 32.234   +08 16 55.94   18376  94.3 17.1 510'  95
2018 09 08 16  13 24 28.001   -09 15 52.15    9441  37.3 19??  25d  93
2018 09 08 17  18 54 16.185   -04 17 44.16   22480 116.9 16.8 260'  82
2018 09 08 18  20 17 14.835   -00 53 18.90   34213 137.2 17.1 6218  83
2018 09 08 19  21 00 19.389   +00 57 25.35   43566 147.5 17.3 3376  84
2018 09 08 20  21 29 15.034   +02 10 44.95   51176 154.2 17.5 2097  86
2018 09 08 21  21 51 16.395   +03 05 05.22   57420 159.0 17.6 1400  87
2018 09 08 22  22 09 20.786   +03 48 17.35   62533 162.6 17.7  978  89
2018 09 08 23  22 24 57.057   +04 24 20.22   66664 165.3 17.7  707  91
2018 09 09 00  22 38 56.248   +04 55 30.11   69914 167.2 17.8  528  92
2018 09 09 01  22 51 50.901   +05 23 11.74   72354 168.3 17.8  411  93
2018 09 09 02  23 04 03.737   +05 48 21.51   74029 168.6 17.8  340  93
2018 09 09 03  23 15 52.078   +06 11 39.14   74971 168.2 17.9  305  92
2018 09 09 04  23 27 30.420   +06 33 34.02   75194 167.1 17.9  304  89
2018 09 09 05  23 39 12.154   +06 54 28.96   74703 165.6 18.0  335  86
2018 09 09 06  23 51 10.996   +07 14 42.46   73490 163.6 18.0  404  84
2018 09 09 07  00 03 42.500   +07 34 30.04   71533 161.3 18.0  515  82
2018 09 09 08  00 17 06.060   +07 54 04.94   68796 158.6 18.0  682  81
2018 09 09 09  00 31 48.111   +08 13 37.98   65224 155.5 18.0  929  82
2018 09 09 10  00 48 27.931   +08 33 15.59   60737 151.8 17.9 1300  82
2018 09 09 11  01 08 09.562   +08 52 53.12   55217 147.3 17.9 1884  83
2018 09 09 12  01 32 49.838   +09 11 51.92   48487 141.6 17.7 2884  85
2018 09 09 13  02 06 37.570   +09 27 29.63   40268 133.7 17.6 4870  87
2018 09 09 14  03 00 50.723   +09 27 05.14   30093 120.8 17.3 168'  90
2018 09 09 15  05 05 28.965   +07 30 42.61   17262  90.6 17.1 601'  95
2018 09 09 16  14 25 32.801   -09 31 17.30   10082  50.7 18??  22d  91
2018 09 09 17  19 09 00.102   -03 25 22.47   23542 119.6 16.8 239'  82
2018 09 09 18  20 26 07.444   -00 16 12.90   35071 138.5 17.1 5941  83
2018 09 09 19  21 07 24.721   +01 27 11.98   44273 148.3 17.4 3277  84
2018 09 09 20  21 35 30.984   +02 36 01.00   51766 154.8 17.5 2055  86
2018 09 09 21  21 57 04.558   +03 27 07.10   57916 159.5 17.6 1383  88
2018 09 09 22  22 14 51.387   +04 07 46.22   62947 163.0 17.7  975  90
2018 09 09 23  22 30 15.722   +04 41 40.76   67005 165.7 17.7  712  91
2018 09 10 00  22 44 06.422   +05 10 58.10   70189 167.5 17.8  540  93
2018 09 10 01  22 56 54.882   +05 36 57.62   72567 168.6 17.8  428  93