"Pseudo-MPEC" for A10bMLz
Created 2019 Jan 27 22:20:18 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 the TLEs for this particular object may not be all that good.
This is a small, very light object of the sort I've been referring to as Empty Trash-Bag Objects, or ETBOs. Judging by its brightness, this object might be a few meters across, in which case its mass appears to be under a kilogram. Note that those are very approximate values. In particular, the last observations shown below, from Peter Birtwhistle at (J95) Great Shefford, show a considerable drop in brightness (Peter says that the mag 21.7 value shouldn't be trusted much, but even with that tossed, it indicates a fainter, and therefore smaller, object.)
At present, we have no idea as to the origin of this object. That's mostly because its past trajectory is really uncertain. As with an empty trash bag blowing down the street, it may zig and zag in unpredictable ways. The nominal orbit, though, suggests that this object has generally had a much higher perigee; it dropped to within a few hundred kilometers on this most recent perigee. I don't see any recent lunar flybys, and wouldn't speculate on when it might hit the earth or moon or leave the earth-moon system.
The retrograde orbit was originally very puzzling. Almost all artsats above low-earth orbit are in prograde orbits. I thought this might just be an old bit of junk that went past the moon and got its orbit flipped around. But the huge non-grav forces on this object probably did the job instead. Run this object back a few months, and you have a prograde orbit of the sort at which nobody would have blinked.
The data currently fit nicely with a three-parameter non-grav fit. For this, we take the usual radial term and add an "along-orbit" A2 term at right angles to it, and an "out of the orbit plane" A3 term at right angles to them both. (Almost the same thing is done for comets, except that the force varies in a more complicated way with distance from the sun and the A3 term is usually negligible.)
The two "sideways" forces are about a quarter the magnitude of the radial force, which seems reasonable. The object is directing some of the sunlight hitting it off at an angle, instead of reflecting it evenly. And/or it absorbs some sunlight, rotates a bit, and re-radiates it. (This is basically the Yarkovsky effect.)
While this model currently fits nicely, that may just reflect a lack of the data required to rubbish it. You can get a good fit to almost any dataset if you add enough parameters. Or as John von Neumann put it :
If you allow me four free parameters I can build a mathematical model that describes exactly everything that an elephant can do. If you allow me a fifth free parameter, the model I build will forecast that the elephant will fly.
So tomorrow's data may rubbish tonight's orbit.
Astrometry:
A10bMLz CK190125:063802744103.00929730+51.53778865 16.92RU I41
A10bMLz CK190125:063832725103.00175582+51.53629207 16.92RU I41
A10bMLz C2019 01 25q)s;?T#k'\6Astrometry0p1A;qd8'Xx[Ni[Ne;Wbfa6'D_rLAb\T05
A10bMLz C2019 01 25yLTQ-(@BW`7h$O8+0]D(cfjyX=W?brhTJO7DqH*c6-gfELP\q2E7T05
A10bMLz C2019 01 256V:$ed./YJmB`/\V\-h\xD[Gr7C.n]fYt[eT_XvEY`3v\o)%+'#fT05
A10bMLz C2019 01 25bJ_dD@ORYbO$A5^.1uWncO#O1y-6\Yx,c+8l]qT2PO!4]fco4cX=T05
A10bMLz C2019 01 25VN==mredacted;ZH+L_W[L-dMun_q(OC6Nq+m(Z0E'jGfp,w+X^pT05
A10bMLz C2019 01 256OrjM.?DnfL(PK/@LOjYMvk1lQE_r-PH%@ug9?5%F=UKOx0@W]pHL01
A10bMLz C2019 01 25fgC4FcgW]#7)tFTUvRepcH@fp\tg+)es))]J:t'Q#x1WNBD[DdG:L01
A10bMLz C2019 01 25E(k(1(R%ZWY6/EG]ci[D3yF'EA:a^2`fXBQ:NW=bhPxwuE4^ho]UL01
A10bMLz C2019 01 25.=rH]PDijra[Bclick83?33-L!/1JlHq$S%A%'YUKwV;XxSF=AYJL01
A10bMLz C2019 01 25G!UZZa[6f7jcm+vk9BbZ!fM5F)5P+\Q17egrbl9R/`7+QP'm0(Y7L01
A10bMLz C2019 01 25C:k[%2-_5oQN!;58@C(4S0GE\M?i6y3QDH0VUpk$!t%/q=):E=H/L01
A10bMLz KC2019 01 25(e3/$D@Y:1];+Xn4OxNNov]ZC)0?cuuv_@%3Z6KPvgbD!7B*elZ$345
A10bMLz KC2019 01 25TFHTAMBUm+nZm86^5@I'T-XfnFEdye2.,:P;2CGZ#:LmSa3VBh\*345
A10bMLz KC2019 01 25eG\hereQUBE_]1(^k_SrS,3@bVby:=G8o/]pEhKAhdYSlqy+Jq80345
A10bMLz KC2019 01 25T8sG0B0m806=QX'd1M60Y`'qq2*Dp[C(Of8vXHfvTDWrV+.@IHitB04
A10bMLz KC2019 01 25Or1W!QpR0r,L==yMH-mfVoVP)*Hx^6M0+2SUc'6I.Sg-inN0KC@UB04
A10bMLz KC2019 01 25RrJ7^$FA(9E6F2w'UkUepx+%/^^q,kDW(([)_V1R!!RgxYCi4b:gB04
A10bMLz KC2019 01 25)0PMg2/oHY4'-YfEIU-cvU)v3a[q1C_xR;mUfortN///ei)0l8q/B04
A10bMLz KC2019 01 25ldJW-cU9%InSwX,t'O#7A;cP)DB:8u`=ccMVBv%vM]83W@c51**NB04
A10bMLz KC2019 01 25-hf-+)JX:m.?i5V[Ig!fgJa;_u4qWxXE?e*i=\K5%;E;3*i].PyH595
A10bMLz KC2019 01 25[^pf;_)1v.GU#FpAYg%IJhS#6Yj/o0`QHVqcoukbv!fBqa8A%c/X595
A10bMLz KC2019 01 25Anli$cSs=(?Y$@yFka^\'!k:A6+RxFMl8=JUJwr,,06+0\F3@(nu595
A10bMLz KC2019 01 25;:Ba-91b=/5I%u3pD,'1cexplanation%!7h=T\fpPcW]VCtRiw1595
A10bMLz KC2019 01 25.85809506 39 38.86 +49 11 26.3 ~1PLI 17.3 GVNEOCPJ95
A10bMLz KC2019 01 25.86005906 39 33.21 +49 11 20.4 ~1PLI 17.3 GVNEOCPJ95
A10bMLz KC2019 01 25.86261106 39 25.85 +49 11 12.3 ~1PLI 17.4 GVNEOCPJ95
A10bMLz KC2019 01 25.86497406 39 19.01 +49 11 04.3 ~1PLI 17.5 GVNEOCPJ95
A10bMLz CK190125:2105070 099.64225 +49.17129 17.5 GV Z80
A10bMLz CK190125:2109070 099.60837 +49.16747 17.3 GV Z80
A10bMLz CK190125:2113070 099.57416 +49.16344 17.2 GV Z80
A10bMLz CK190125:2117070 099.54003 +49.15929 17.5 GV Z80
A10bMLz CK190125:2121070 099.50582 +49.15493 17.2 GV Z80
A10bMLz CK190125:2125070 099.47109 +49.15042 V Z80
A10bMLz CK190125:235811 099.93376 +48.90261 17.4 Vq W34
A10bMLz CK190126:000619 099.87661 +48.91116 17.6 Vq W34
A10bMLz CK190126:001337 099.82382 +48.91828 17.5 Vq W34
A10bMLz CK190126:003044 099.69613 +48.93307 17.2 Vq W34
A10bMLz CK190127:21071618 093.51560 +45.48795 21.7 GV J95
A10bMLz CK190127:21134261 093.48622 +45.48388 20.8 GV J95
A10bMLz CK190127:21214215 093.45015 +45.47787 20.3 GV J95
Station data:
(345) Sobaeksan Optical Astronomy Observatory (N36.934554 E128.457500)
South Korea.
(595) Farra d'Isonzo (N45.915734 E13.525780) Italy. Observers L.
Bittesini, F. Fabris, E. Pettarin, F. Piani. Measurer E. Pettarin. 0.30-m
f/4.5 reflector + CCD.
(B04) OAVdA, Saint-Barthelemy (N45.789693 E7.478510) Italy. Observer A.
Carbognani. 0.81-m f/7.9 reflector + CCD.
(I41) Palomar Mountain--ZTF (N33.357340 W116.859780) US/California.
Observer A. U. Tomatic. Measurers H.-W. Lin, F. J. Masci, D. Streaks,
Q.-Z. Ye.
(J95) Great Shefford (N51.474969 W1.447003) UK. Observer P. Birtwhistle.
(L01) Višnjan Observatory, Tičan (N45.290900 E13.749300) Croatia.
Observers K. Korlević, E. Pettarin. Measurer E. Pettarin. 1.0-m f/2.9
reflector + CCD.
(T05) ATLAS-HKO, Haleakala (N20.707582 W156.257008) US/Hawaii. Observers
L. Denneau, A. Heinze, H. Weiland, J. Tonry, H. Flewelling, A.
Fitzsimmons, D. Young, B. Stalder. Measurers L. Denneau, A. Heinze, J.
Tonry. 0.5-m f/2.0 Schmidt + CCD.
(W34) Squirrel Valley Observatory, Columbus (N35.225393 W82.154700)
US/North Carolina. Observer R. L. Flynn.
(Z80) Northolt Branch Observatory (N51.554661 W0.371920) UK. Observer G.
Wells. Measurer D. Bamberger.
Orbital elements: A10bMLz
Perigee 2019 Jan 24.013862 +/- 0.000621 TT = 0:19:57 (JD 2458507.513862)
A1: 1.46e-5 +/- 2.11e-7 A2: -3.38e-6 +/- 1.65e-7 A3: 3.81e-6 +/- 8.89e-8 AU/day^2
Epoch 2019 Jan 25.0 TT = JDT 2458508.5 Gray
M 24.18911887 +/- 0.050 (J2000 equator)
n 24.52914412 +/- 0.0372 Peri. 308.41594 +/- 0.006
a253210.615 +/- 256 Node 233.64302 +/- 0.0020
e 0.9723339 +/- 4.51e-5 Incl. 121.56224 +/- 0.0018
P 14.68d H 29.8 G 0.15 U 10.5
q 7005.34773 +/- 5.93 Q 499415.883 +/- 515
From 42 observations 2019 Jan. 25-27; mean residual 0".309
Residuals in arcseconds: 190125 I41 .208+ 9.5m- 190125 345 .177+ .518+ 190125 J95 .159+ .145+ 190125 I41 .428+ .072+ 190125 345 .581- .024- 190125 Z80 .064+ .017- 190125 T05 .267- .236+ 190125 B04 .492- .049+ 190125 Z80 .549+ .013- 190125 T05 .246- .199+ 190125 B04 .224+ .869- 190125 Z80 .377+ .133- 190125 T05 .383- .093+ 190125 B04 .019+ .061+ 190125 Z80 .498+ .049- 190125 T05 .089+ .245+ 190125 B04 .361- .427+ 190125 Z80 .519+ .084- 190125 T05 .537- .255+ 190125 B04 .125+ .217- 190125 Z80 .612- .021- 190125 L01 .268- .282+ 190125 595 .306- .011- 190125 W34 .163- .040- 190125 L01 .356- .409+ 190125 595 .157- .071- 190126 W34 .267+ .077+ 190125 L01 .413- .230+ 190125 595 .390- 1.1m+ 190126 W34 .024- .088- 190125 L01 .418- .146+ 190125 595 .414- .068+ 190126 W34 .209+ .115- 190125 L01 .367- .492+ 190125 J95 .144- .012+ 190127 J95 .190+ .934- 190125 L01 .384- .318+ 190125 J95 .046- .051+ 190127 J95 .223- .238+ 190125 345 .019- .178+ 190125 J95 .093+ .121+ 190127 J95 .472+ .260- Ephemerides (geocentric): Date (UTC) HH RA Dec delta elong mag " sig PA ---- -- -- -- ------------- ----------- ------ ----- --- ---- --- 2019 01 27 12 06 16 24.782 +46 08 14.74 415322 139.9 18.6 1.66 49 2019 01 27 14 06 15 43.597 +46 00 41.95 420046 139.8 18.6 1.94 48 2019 01 27 16 06 15 03.756 +45 53 16.70 424673 139.7 18.7 2.23 47 2019 01 27 18 06 14 25.194 +45 45 58.60 429205 139.6 18.7 2.53 47 2019 01 27 20 06 13 47.851 +45 38 47.30 433645 139.5 18.7 2.85 46 2019 01 27 22 06 13 11.671 +45 31 42.48 437995 139.4 18.7 3.18 46 2019 01 28 00 06 12 36.601 +45 24 43.82 442257 139.3 18.8 3.53 45 2019 01 28 02 06 12 02.595 +45 17 51.03 446432 139.2 18.8 3.89 45 2019 01 28 04 06 11 29.607 +45 11 03.85 450523 139.1 18.8 4.27 45 2019 01 28 06 06 10 57.596 +45 04 22.01 454532 139.0 18.8 4.65 44 2019 01 28 08 06 10 26.523 +44 57 45.28 458460 138.9 18.9 5.05 44 2019 01 28 10 06 09 56.352 +44 51 13.44 462309 138.8 18.9 5.46 43 2019 01 28 12 06 09 27.049 +44 44 46.27 466081 138.7 18.9 5.88 43 2019 01 28 14 06 08 58.583 +44 38 23.57 469777 138.6 18.9 6.31 43 2019 01 28 16 06 08 30.925 +44 32 05.15 473398 138.5 18.9 6.75 43 2019 01 28 18 06 08 04.045 +44 25 50.84 476946 138.4 19.0 7.20 42 2019 01 28 20 06 07 37.919 +44 19 40.45 480422 138.4 19.0 7.67 42 2019 01 28 22 06 07 12.523 +44 13 33.84 483827 138.3 19.0 8.14 42 2019 01 29 00 06 06 47.832 +44 07 30.85 487163 138.2 19.0 8.62 41 2019 01 29 02 06 06 23.826 +44 01 31.33 490431 138.1 19.0 9.11 41 2019 01 29 04 06 06 00.484 +43 55 35.15 493631 138.0 19.0 9.61 41 2019 01 29 06 06 05 37.786 +43 49 42.17 496766 137.9 19.1 10.1 41 2019 01 29 08 06 05 15.716 +43 43 52.28 499835 137.8 19.1 10.6 40 2019 01 29 10 06 04 54.255 +43 38 05.35 502840 137.7 19.1 11.2 40 2019 01 29 12 06 04 33.388 +43 32 21.27 505783 137.6 19.1 11.7 40 2019 01 29 14 06 04 13.099 +43 26 39.93 508663 137.5 19.1 12.3 40 2019 01 29 16 06 03 53.374 +43 21 01.22 511481 137.4 19.1 12.8 39 2019 01 29 18 06 03 34.199 +43 15 25.06 514239 137.3 19.1 13.4 39 2019 01 29 20 06 03 15.562 +43 09 51.34 516938 137.2 19.2 13.9 39 2019 01 29 22 06 02 57.449 +43 04 19.98 519577 137.2 19.2 14.5 39 2019 01 30 00 06 02 39.850 +42 58 50.88 522159 137.1 19.2 15.1 38 2019 01 30 02 06 02 22.753 +42 53 23.96 524682 137.0 19.2 15.7 38 2019 01 30 04 06 02 06.148 +42 47 59.15 527150 136.9 19.2 16.3 38 2019 01 30 06 06 01 50.024 +42 42 36.36 529561 136.8 19.2 16.9 38 2019 01 30 08 06 01 34.374 +42 37 15.53 531916 136.7 19.2 17.6 37 2019 01 30 10 06 01 19.186 +42 31 56.58 534217 136.6 19.2 18.2 37 2019 01 30 12 06 01 04.454 +42 26 39.44 536463 136.6 19.3 18.8 37 2019 01 30 14 06 00 50.169 +42 21 24.05 538656 136.5 19.3 19.5 37 2019 01 30 16 06 00 36.322 +42 16 10.34 540796 136.4 19.3 20.1 36 2019 01 30 18 06 00 22.908 +42 10 58.25 542883 136.3 19.3 20.8 36 2019 01 30 20 06 00 09.919 +42 05 47.73 544918 136.2 19.3 21.5 36 2019 01 30 22 05 59 57.348 +42 00 38.71 546901 136.1 19.3 22.2 36 2019 01 31 00 05 59 45.188 +41 55 31.14 548834 136.1 19.3 22.9 35 2019 01 31 02 05 59 33.435 +41 50 24.96 550716 136.0 19.3 23.6 35 2019 01 31 04 05 59 22.083 +41 45 20.13 552547 135.9 19.3 24.3 35 2019 01 31 06 05 59 11.125 +41 40 16.59 554329 135.8 19.4 25.0 35 2019 01 31 08 05 59 00.557 +41 35 14.30 556061 135.7 19.4 25.7 34 2019 01 31 10 05 58 50.374 +41 30 13.20 557744 135.7 19.4 26.4 34 2019 01 31 12 05 58 40.571 +41 25 13.25 559379 135.6 19.4 27.2 34 2019 01 31 14 05 58 31.144 +41 20 14.41 560965 135.5 19.4 28.0 34 2019 01 31 16 05 58 22.089 +41 15 16.62 562504 135.4 19.4 28.7 33 2019 01 31 18 05 58 13.401 +41 10 19.86 563994 135.4 19.4 29.5 33 2019 01 31 20 05 58 05.078 +41 05 24.07 565438 135.3 19.4 30.3 33 2019 01 31 22 05 57 57.114 +41 00 29.21 566834 135.2 19.4 31.1 33 2019 02 01 00 05 57 49.508 +40 55 35.26 568184 135.1 19.4 31.9 32 2019 02 01 02 05 57 42.255 +40 50 42.16 569488 135.1 19.4 32.7 32 2019 02 01 04 05 57 35.353 +40 45 49.88 570745 135.0 19.4 33.5 32 2019 02 01 06 05 57 28.798 +40 40 58.38 571956 134.9 19.4 34.3 32 2019 02 01 08 05 57 22.589 +40 36 07.62 573122 134.9 19.5 35.2 31 2019 02 01 10 05 57 16.722 +40 31 17.57 574242 134.8 19.5 36.0 31 2019 02 01 12 05 57 11.196 +40 26 28.20 575317 134.7 19.5 36.9 31 2019 02 01 14 05 57 06.007 +40 21 39.47 576347 134.6 19.5 37.8 31 2019 02 01 16 05 57 01.154 +40 16 51.34 577333 134.6 19.5 38.7 30 2019 02 01 18 05 56 56.635 +40 12 03.79 578273 134.5 19.5 39.6 30 2019 02 01 20 05 56 52.448 +40 07 16.77 579169 134.4 19.5 40.5 30 2019 02 01 22 05 56 48.591 +40 02 30.26 580021 134.4 19.5 41.4 30 2019 02 02 00 05 56 45.063 +39 57 44.22 580829 134.3 19.5 42.3 29 2019 02 02 02 05 56 41.862 +39 52 58.62 581592 134.2 19.5 43.3 29 2019 02 02 04 05 56 38.987 +39 48 13.44 582312 134.2 19.5 44.2 29 2019 02 02 06 05 56 36.436 +39 43 28.63 582988 134.1 19.5 45.2 28 2019 02 02 08 05 56 34.209 +39 38 44.17 583621 134.1 19.5 46.2 28 2019 02 02 10 05 56 32.305 +39 34 00.03 584209 134.0 19.5 47.1 28 2019 02 02 12 05 56 30.722 +39 29 16.17 584755 133.9 19.5 48.2 28 2019 02 02 14 05 56 29.460 +39 24 32.57 585257 133.9 19.5 49.2 27 2019 02 02 16 05 56 28.518 +39 19 49.20 585716 133.8 19.5 50.2 27 2019 02 02 18 05 56 27.896 +39 15 06.02 586131 133.8 19.5 51.3 27 2019 02 02 20 05 56 27.592 +39 10 23.01 586504 133.7 19.5 52.3 26 2019 02 02 22 05 56 27.608 +39 05 40.13 586833 133.6 19.5 53.4 26 2019 02 03 00 05 56 27.942 +39 00 57.36 587119 133.6 19.5 54.5 26 2019 02 03 02 05 56 28.595 +38 56 14.67 587363 133.5 19.5 55.6 25