2012 XM55 Goldstone Radar Observations Planning
2012 XM55 was discovered by the Mt. Lemmon Survey on December 8, 2012. Nothing is known about this object other than its absolute magnitude of 27.8, which suggests a diameter within a factor of two of only 14 meters. As such, it's one of the smallest NEAs we've ever tried to observe at Goldstone. 2012 XM55 is on the "NHATS" list of potential human mission targets, so there's considerable interest in improving its orbit and understanding its physical properties. 2012 XM55 will approach within 0.00783 AU (3.0 lunar distances) on Decmeber 23. We're going to observe it during time already scheduled for Toutatis on Dec. 20-22 when the SNRs should be sufficient to get a detection. The round-trip light travel times will be unusually short and less than 10 seconds. Normally we'd receive at DSS-13 in situations like this, but the SNRs would be too weak to see an echo if we did that, so we're going to do these observations monostatically even though the round-trip times will be as short as 8 seconds. Thank you to the many people who responded to our request for astrometry and who observed this object!
Orbital and Physical Characteristics orbit type Apollo semimajor axis 1.102 AU eccentricity 0.135 inclination 1.3 deg perihelion distance 0.953 AU aphelion distance 1.251 AU absolute magnitude (H) 27.8 diameter ~14 meters (within a factor of two) rotation period unknown pole direction unknown lightcurve amplitude unknown spectral class unknown Last update: 2012 December 19
M.P.E.C. 2012-X47 Issued 2012 Dec. 10, 20:49 UT The Minor Planet Electronic Circulars contain information on unusual minor planets and routine data on comets. They are published on behalf of Commission 20 of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Prepared using the Tamkin Foundation Computer Network MPC@CFA.HARVARD.EDU URL http://www.minorplanetcenter.net/ ISSN 1523-6714 2012 XM55 Observations: K12X55M* C2012 12 08.27998 04 27 49.06 +23 37 38.1 20.8 VrEX047G96 K12X55M C2012 12 08.28591 04 27 48.02 +23 38 00.4 20.3 VrEX047G96 K12X55M C2012 12 08.29262 04 27 46.80 +23 38 25.6 20.1 VrEX047G96 K12X55M C2012 12 08.29856 04 27 45.75 +23 38 48.0 20.7 VrEX047G96 K12X55M C2012 12 08.33575 04 27 39.33 +23 41 04.1 20.4 VrEX047G96 K12X55M C2012 12 08.33735 04 27 39.06 +23 41 09.9 21.1 VrEX047G96 K12X55M C2012 12 08.33895 04 27 38.80 +23 41 15.1 20.3 VrEX047G96 K12X55M KC2012 12 08.34855 04 27 37.36 +23 41 53.0 20.8 RoEX047291 K12X55M KC2012 12 08.34967 04 27 37.14 +23 41 57.1 20.8 RoEX047291 K12X55M KC2012 12 08.35079 04 27 37.01 +23 42 00.7 20.4 RoEX047291 K12X55M C2012 12 09.30868 04 26 49.81 +24 47 05.9 20.0 VrEX047G96 K12X55M C2012 12 09.30925 04 26 49.81 +24 47 08.4 20.2 VrEX047G96 K12X55M C2012 12 09.30980 04 26 49.66 +24 47 10.9 20.0 VrEX047G96 K12X55M C2012 12 09.31038 04 26 49.56 +24 47 13.6 20.5 VrEX047G96 K12X55M KC2012 12 09.99207 04 26 07.91 +25 37 10.8 20.2 RtEX047204 K12X55M KC2012 12 10.00484 04 26 09.29 +25 37 41.6 uEX047J95 K12X55M KC2012 12 10.01102 04 26 08.33 +25 38 09.5 uEX047J95 K12X55M KC2012 12 10.01412 04 26 04.10 +25 38 49.5 tEX047204 K12X55M KC2012 12 10.01715 04 26 07.30 +25 38 37.7 19.9 RuEX047J95 K12X55M C2012 12 10.29686 04 25 50.91 +26 03 07.6 19.8 VrEX047G96 K12X55M C2012 12 10.30178 04 25 49.80 +26 03 31.4 20.6 VrEX047G96 K12X55M C2012 12 10.30670 04 25 48.86 +26 03 54.5 20.5 VrEX047G96 K12X55M C2012 12 10.31163 04 25 47.82 +26 04 17.6 20.2 VrEX047G96 Observer details: 204 Schiaparelli Observatory. Observer L. Buzzi. 0.38-m f/6.8 reflector + CCD. 291 LPL/Spacewatch II. Observer T. H. Bressi. 1.8-m f/2.7 reflector + CCD. G96 Mt. Lemmon Survey. Observer R. E. Hill. Measurers A. Boattini, E. J. Christensen, A. R. Gibbs, A. D. Grauer, R. E. Hill, J. A. Johnson, R. A. Kowalski, S. M. Larson, R. H. McNaught. 1.5-m reflector + CCD. J95 Great Shefford. Observer P. Birtwhistle. 0.40-m f/6.0 Schmidt-Cassegrain + CCD. Orbital elements: 2012 XM55 Earth MOID = 0.0083 AU Epoch 2012 Sept. 30.0 TT = JDT 2456200.5 MPC M 254.12361 (2000.0) P Q n 0.85543940 Peri. 60.56689 -0.70590277 -0.70788312 a 1.0990309 Node 74.35769 +0.64070859 -0.65292640 e 0.1302139 Incl. 1.46094 +0.30198308 -0.26942273 P 1.15 H 27.8 G 0.15 U 7 Residuals in seconds of arc 121208 G96 0.4+ 0.3- 121208 291 0.6- 0.4+ 121210 J95 0.5+ 0.2- 121208 G96 0.5+ 0.4- 121208 291 0.1+ 0.0 121210 204 0.0 0.4+ 121208 G96 0.0 0.4- 121209 G96 1.3- 0.4- 121210 J95 0.3+ 0.0 121208 G96 0.1- 0.2- 121209 G96 0.2+ 0.3- 121210 G96 0.1- 0.1- 121208 G96 0.3+ 0.2+ 121209 G96 0.4- 0.1- 121210 G96 1.1- 0.2+ 121208 G96 0.3+ 0.3+ 121209 G96 0.3- 0.2+ 121210 G96 0.1+ 0.1- 121208 G96 0.5+ 0.2- 121209 204 0.1+ 0.1+ 121210 G96 0.1- 0.3- 121208 291 0.2- 0.3+ 121210 J95 0.3- 0.2+ Ephemeris: 2012 XM55 a,e,i = 1.10, 0.13, 1 q = 0.9559 Date TT R. A. (2000) Decl. Delta r Elong. Phase V 2012 11 10 04 31 52.1 +14 02 12 0.08493 1.0695 158.0 20.3 23.6 ... 2012 11 25 04 33 26.1 +16 13 29 0.05129 1.0378 171.6 8.0 22.0 ... 2012 12 03 04 31 06.1 +19 28 09 0.03615 1.0218 176.9 3.0 20.9 ... 2012 12 09 04 27 11.6 +24 26 03 0.02580 1.0104 171.4 8.4 20.5 2012 12 10 04 26 13.3 +25 39 55 0.02416 1.0086 170.0 9.8 20.4 2012 12 11 04 25 06.9 +27 04 13 0.02255 1.0068 168.4 11.3 20.3 ... 2012 12 17 04 12 38.6 +42 01 48 0.01361 0.9963 154.0 25.6 19.6 ... 2012 12 25 17 39 07.5 +66 34 25 0.0080440.9836 90.2 89.3 20.4 ... 2013 01 09 16 41 54.3 +04 51 48 0.02741 0.9651 47.4 131.4 25.8 A. U. Tomatic (C) Copyright 2012 MPC M.P.E.C. 2012-X47
Target Name: 2012 XM55 2012XM55: D = 0.01 km, P = 0.5000 hr, OC albedo = 0.100 Goldstone: G = 0.94 K/Jy, Tsys = 18.0 K, P = 430 kW, elev >= 30.00 deg, unhopped t_down = 4 s, t_switch = 4 s start date window RA, dec dist runs SNR SNR/run 2012 Dec 17 23:39-12:45 62, +48 0.012 1707 51 1 2012 Dec 18 23:09-12:58 60, +54 0.011 1969 76 2 2012 Dec 19 22:27-13:23 57, +60 0.010 2325 114 3 2012 Dec 20 21:16-14:35 52, +69 0.009 2899 167 3 2012 Dec 21 18:30-11:25 38, +77 0.008 4213 241 4 2012 Dec 22 17:59-07:54 348, +83 0.008 4361 284 5 2012 Dec 23 13:21-03:15 285, +79 0.008 4411 294 5 2012 Dec 24 12:52-06:54 266, +69 0.008 3195 245 5 2012 Dec 24 09:33-03:13 266, +69 0.008 3195 245 5 2012 Dec 25 11:18-01:49 260, +58 0.008 2556 190 4 2012 Dec 26 11:48-01:00 257, +49 0.009 2165 136 3 2012 Dec 27 12:05-00:26 255, +41 0.010 1865 92 2 2012 Dec 28 12:17-00:00 254, +34 0.011 1623 62 2 2012 Dec 29 12:24-23:40 253, +29 0.012 1425 42 1 Note: this object is circumpolar at Goldstone, so we set the horizons = 30 deg in order to split up the tracks. The rise-set times above are inaccurate on days when when XM55 is circumpolar. PRDX files were also adjusted to deal with rise-set issues. Goldstone SNRs assume Ptx = 430 kW and Tsys = 18 K
Goldstone tracks: UT UT PDT Duration Round-trip DOY Date TX Window TX Window hh:mm time (sec) SNR/Run --- ---- --------- --------- --------- --------- ------- 355 Dec 20 0535 1015 2135-0215 Dec 19-20 4:40 9.6 3 Entirely overlaps Toutatis 356 Dec 21 0705 1155 2305-0355 Dec 20-21 4:50 8.7 4 Entirely overlaps Toutatis 357 Dec 22 0550 1205 2150-0405 Dec 21-22 6:15 8.1 5 Entirely overlaps Toutatis With such short round-trip times, during monostatic observations, we'll have to throw out about 4 seconds of data during switching from transmit to receive. The Dec. 21 and 22 tracks also overlap time for Apophis. There are no tracks scheduled at Arecibo.
From Jon Giorgini, 2012 Dec. 19: Updating 2012 XM55 to use the latest 60 optical measurements from Dec 8-19, 2012 (including the e-mailed data from L. Buzzi (site 204), the orbit solution and files on aardvark were updated to .s13. Formal 3-sigma X-band uncertainties for .s13: Date__(UT)__HR:MN POS_3sigma DOP_X_3sig RT_delay_3sig 2012-Dec-19 00:00 3.328 309.14 0.031764 2012-Dec-20 00:00 4.621 263.50 0.028896 2012-Dec-21 00:00 8.232 205.26 0.026548 2012-Dec-22 00:00 15.842 133.92 0.024852 2012-Dec-23 00:00 28.556 52.87 0.023935 - - - - - - - - - - - - - - - - - - - - From Horizons, 2012 Dec. 18: JPL/Horizons solution 10 # obs: 52 (9 days): Date__(UT)__HR:MN R.A._(J2000.0)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig 2012-Dec-20 00:00 *m 58.33043 58.42121 0.00999562286139 8.532 84.36 306.61 0.033942 2012-Dec-21 00:00 *m 53.81297 66.41031 0.00906919329543 14.972 65.95 239.70 0.031208 2012-Dec-22 00:00 *m 42.48957 75.60060 0.00835924377410 26.209 43.52 158.16 0.029224 2012-Dec-23 00:00 *m 352.55482 83.28409 0.00792285143285 43.286 18.32 66.57 0.028130 2012-Dec-24 00:00 *m 280.40079 77.64959 0.00780526031856 65.211 10.96 39.83 0.028013 - - - - - - - - - - - - - - - - - - - - From Jon Giorgini, 2012 Dec 17: Using 49 optical measurements (Dec 8-15, 2012), 2012 XM55 orbit solution #9 was estimated and OSOD w/nominal predicts established on aardvark in the /2012xm55 sub-directory. Formal 3-sigma X-band uncertainties for .s9: Date__(UT)__HR:MN POS_3sigma DOP_X_3sig RT_delay_3sig 2012-Dec-20 00:00 25.028 325.03 0.036414 2012-Dec-21 00:00 39.596 255.82 0.033519 2012-Dec-22 00:00 60.186 173.42 0.031391 2012-Dec-23 00:00 86.219 89.47 0.030172 There is a day where it doesn't set below 18 degrees elevation, so I used 18 deg. as the rise-set cut-off. Hopefully that doesn't cut into scheduled track time. ********************************************************************************************** Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination: Date__(UT)__HR:MN R.A._(J2000.0)_DEC. delta APmag S-O-T /r T-O-M/Illu% 2012-Dec-12 00:00 65.96005 28.68614 0.02096616660176 20.21 166.7544 /T 169.0/ 2.8 2012-Dec-13 00:00 65.59018 30.55533 0.01941425276866 20.10 164.8611 /T 167.1/ 0.2 2012-Dec-14 00:00 65.15443 32.73676 0.01789716683451 20.00 162.7246 /T 153.6/ 0.7 2012-Dec-15 00:00 64.63110 35.30539 0.01641982311894 19.89 160.2766 /T 138.8/ 4.1 2012-Dec-16 00:00 63.98590 38.35891 0.01498920662896 19.77 157.4248 /T 124.1/ 10.2 2012-Dec-17 00:00 63.16153 42.02436 0.01361538000671 19.66 154.0449 /T 110.0/ 18.2 2012-Dec-18 00:00 62.05566 46.46440 0.01231293208979 19.56 149.9731 /T 96.6/ 27.6 2012-Dec-19 00:00 60.46795 51.87831 0.01110296584048 19.47 145.0015 /T 84.5/ 37.6 2012-Dec-20 00:00 57.95040 58.48374 0.01001554904005 19.41 138.8869 /T 74.5/ 47.9 2012-Dec-21 00:00 53.27119 66.43991 0.00909192768797 19.41 131.3948 /T 67.8/ 57.9 2012-Dec-22 00:00 41.60098 75.55731 0.00838433696459 19.49 122.4079 /T 66.1/ 67.4 2012-Dec-23 00:00 351.91443 83.06747 0.00794933998678 19.68 112.1040 /T 70.3/ 76.0 2012-Dec-24 00:00 281.36794 77.54389 0.00783171369814 20.00 101.0945 /T 79.4/ 83.6 2012-Dec-25 00:00 264.85375 66.66923 0.00804492065947 20.47 90.3115 /L 91.0/ 89.9 2012-Dec-26 00:00 259.07002 56.13928 0.00856397273512 21.03 80.6210 /L 102.6/ 94.8 2012-Dec-27 00:00 256.18375 46.93866 0.00933785691272 21.63 72.4952 /L 112.1/ 98.1 2012-Dec-28 00:00 254.46562 39.24548 0.01030942414318 22.23 65.9948 /L 118.2/ 99.8
We're going to start with the CW setup below. We know nothing about the rotation period, so we'll start with a standard setup in the hope that it will resolve the object. Due to the very short round-trip time, we will NOT hop the transmitter. 3-sigma Doppler uncertainties are still about 260 Hz, so a bandwidth of 4000 Hz will be sufficient to include the echo. Obviously the echo could have a significant offset from zero Hz. TX polarization RCP RCV polarization LCP & RCP Frequency hops: no hops Bandwidth: 4000 Hz Sampling interval: 2500 x 0.1 usec VME FFT for PSD files: 4096 for 0.98-Hz resolution Ranging setups: --------------------------------------------------------------------------- 10-usec baud 10 usec code 127 PRP 1270 usec FFT 128 ncoh 1 bandwidth 787 Hz resolution 6.15 Hz TXOFF +100Hz (echo in bin 64+16=80) --------------------------------------------------------------------------- 11-usec baud 11 usec code 127 PRP 1397 usec FFT 128 ncoh 1 bandwidth 716 Hz resolution 5.6 Hz TXOFF +100 Hz (echo in bin 64+18=82) ------------------------------------------------------------------------- 1-usec baud 1 usec code 255 FFT 256 ncoh 6 bandwidth 653.6 Hz resolution 2.55 Hz TXOFF +50 Hz -> echo would be centered at 128 + 20 = 148 ------------------------------------------------------------------------- 0.125-usec imaging baud 0.125 usec code 511 FFT 1024 ncoh 150 bandwidth 104.4 Hz resolution 0.1 Hz TXOFF +10 Hz -> echo would be centered at 512 + 98 = 610 _____________________________________________________________________ POSSIBLE RANGING SETUPS: (code=127, FFT=64, single-pol'n) These are from JX, w/ max-band (min-acc) options from Ray Jurgens. Currently configured for 5-sec records. _______________________________________________________________________ Setup Baud RP 1-acc 1-acc usec m usec band res acc band res _______________________________________________________________________ JX1XS110 11.000 1650 1397.0 715.8 11.2 2 358 5.6 JX1XS070 7.000 1050 889.0 1124.9 17.6 3 375 5.9 JX1XS020 2.000 300 254.0 3937.0 61.5 12 328 5.1 4 984 15.4 JX1XS010 1.000 150 127.0 7874.0 123.0 41 192 3.0 8 984 15.4 JX1XS005 0.500 75 63.5 15748.0 246.1 123 128 2.0 15 1050 16.4 JX1XS002 0.250 37.5 31.75 31496.1 492.1 492 64 1.0 30 1050 16.4 JX1XS001 0.125 18.75 15.875 62992.1 984.3 1970 32 0.5 60 1050 16.4 ____________________________________________________________________
OSOD and predicts are on aardvark The macro below corresponds to solution 9, but we already know that we'll update it with a new solution before the track on Dec. 20. WFG: /export/data3/osod/ops/2012xm55/PRDX.OUT.14v-14-14.s13 /PUNCH.OUT.14v-14-14.s13 /EPH.OUT.s13 POINTING TX Offsets Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD 2012 12 20 355 050000 57.5853 60.1704 A 9.75 13 2012 12 20 355 060000 57.3207 60.4904 A 0.7 0.9 9.71 2012 12 20 355 070000 57.0512 60.8003 AB 9.67 2012 12 20 355 080000 56.7847 61.1005 B 0.7 0.8 9.63 2012 12 20 355 090000 56.5283 61.3924 BC 9.60 2012 12 20 355 100000 56.2887 61.6782 C 0.6 0.8 9.56 2012 12 20 355 110000 56.0707 61.9605 C 9.52 2012 12 21 356 070000 51.0828 69.1871 A 8.81 13 2012 12 21 356 080000 50.5641 69.5316 AB 1.2 0.8 8.78 2012 12 21 356 090000 50.0561 69.8661 AB 1.2 0.8 8.76 2012 12 21 356 100000 49.5678 70.1937 BC 8.73 2012 12 21 356 110000 49.1059 70.5180 C 1.0 0.8 8.70 2012 12 21 356 120000 48.6741 70.8431 C 8.67 2012 12 22 357 050000 36.8637 77.7437 A 8.23 13 2012 12 22 357 060000 35.3680 78.1026 A 3.5 0.8 8.20 2012 12 22 357 070000 33.8161 78.4409 AB 8.19 2012 12 22 357 080000 32.2281 78.7608 B 3.6 0.7 8.17 2012 12 22 357 090000 30.6212 79.0660 BC 8.15 2012 12 22 357 100000 29.0066 79.3609 C 3.6 0.6 8.13 2012 12 22 357 110000 27.3878 79.6503 CD 8.11 2012 12 22 357 120000 25.7594 79.9390 D 3.7 0.7 8.10 2012 12 22 357 130000 24.1056 80.2312 D 8.08 Transmit offsets are given in millidegrees.
PRDX.OUT.14f-14-14.s13 TRANSMITTER: STATION #14, RECEIVER: STATION #14 RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL 2012 DEC 20 05:30 9.7336841141 96683.903 357.3664 60.3317 57.454 65.036 2012 DEC 20 05:40 9.7269283544 96080.676 359.9175 60.3849 57.410 65.041 2012 DEC 20 05:50 9.7202148143 95479.431 2.4689 60.4378 57.365 64.938 2012 DEC 20 06:00 9.7135433189 94881.121 5.0204 60.4904 57.321 64.728 2012 DEC 20 06:10 9.7069136320 94286.687 7.5720 60.5428 57.276 64.416 2012 DEC 20 06:20 9.7003254466 93697.060 10.1237 60.5948 57.231 64.005 2012 DEC 20 06:30 9.6937783962 93113.156 12.6755 60.6466 57.186 63.500 2012 DEC 20 06:40 9.6872720452 92535.881 15.2273 60.6981 57.141 62.910 2012 DEC 20 06:50 9.6808059005 91966.121 17.7791 60.7494 57.096 62.238 2012 DEC 20 07:00 9.6743794023 91404.744 20.3309 60.8003 57.051 61.493 2012 DEC 20 07:10 9.6679919356 90852.598 22.8825 60.8510 57.006 60.682 2012 DEC 20 07:20 9.6616428216 90310.512 25.4341 60.9014 56.962 59.810 2012 DEC 20 07:30 9.6553313296 89779.290 27.9855 60.9516 56.917 58.884 2012 DEC 20 07:40 9.6490566681 89259.709 30.5367 61.0015 56.873 57.911 2012 DEC 20 07:50 9.6428179971 88752.524 33.0877 61.0511 56.829 56.896 2012 DEC 20 08:00 9.6366144197 88258.458 35.6385 61.1005 56.785 55.844 2012 DEC 20 08:10 9.6304449918 87778.209 38.1890 61.1497 56.741 54.760 2012 DEC 20 08:20 9.6243087239 87312.442 40.7391 61.1987 56.698 53.649 2012 DEC 20 08:30 9.6182045761 86861.791 43.2889 61.2474 56.655 52.514 2012 DEC 20 08:40 9.6121314702 86426.856 45.8383 61.2959 56.612 51.359 2012 DEC 20 08:50 9.6060882819 86008.205 48.3873 61.3443 56.570 50.189 2012 DEC 20 09:00 9.6000738511 85606.369 50.9359 61.3924 56.528 49.005 2012 DEC 20 09:10 9.5940869842 85221.844 53.4840 61.4404 56.487 47.811 2012 DEC 20 09:20 9.5881264488 84855.090 56.0316 61.4882 56.446 46.609 2012 DEC 20 09:30 9.5821909845 84506.528 58.5787 61.5359 56.406 45.402 2012 DEC 20 09:40 9.5762793051 84176.540 61.1253 61.5834 56.366 44.192 2012 DEC 20 09:50 9.5703900937 83865.471 63.6712 61.6308 56.327 42.981 2012 DEC 20 10:00 9.5645220137 83573.625 66.2166 61.6781 56.289 41.772 2012 DEC 20 10:10 9.5586737080 83301.265 68.7614 61.7254 56.251 40.566 2012 DEC 20 10:20 9.5528438052 83048.616 71.3056 61.7725 56.213 39.364
2012 XM55 GOLDSTONE MASTERLOG
============================================================================== Receive TX Setup hops dwell code ncoh FFT runs start -stop OSOD offset Poln Notes ------------------------------------------------------------------------------
Dr. Lance A. M. Benner | PHONE: (818) 354-7412 Mail Stop 183-601 | FAX: (818) 393-4445 Jet Propulsion Laboratory | email: lance.benner@jpl.nasa.gov California Institute of Technology | Plan: To live long and prosper Pasadena, CA 91109-8099 http://echo.jpl.nasa.gov/asteroids/2012XM55/2012XM55_planning.html