Goldstone Radar Observations Planning: (398188) 2010 LE15
2010 LE15 was discovered on 2010 June 3 by NASA's Wide-field Infrared Survey Explorer (WISE) spacecraft. Thermal modeling of the WISE data by A. K. Mainzer et al. (2011) yields a diameter of 440 meters and an optical albedo of 0.15. Recent lightcurves obtained by Joe Pollock and Brian Warner (pers. comm.) indicate that the rotation period is about 15 h and yield a lightcurve amplitude of 0.8 magnitudes, implying an elongated shape. The spectral class is unknown, but given the optical albedo, it seems likely that this is not an optically-dark or bright asteroid. This asteroid will approach within 0.0399 AU (15.5 lunar distances) on August 12 when it will be a strong radar target. If the rotation period really is at least 20 h, then we hope to get images with a resolution at least as fine as 1/8 usec. The asteroid is getting brighter, so it's possible that more lightcurves and thus more detailed information on the spin state could become available soon. Observations at Goldstone are scheduled on August 9-13. Arecibo observations are scheduled from July 31-August 3. 2010 LE15 will move too far south for Arecibo to track after August 6 and too far south for Goldstone to track after August 13. Update: Arecibo observations on August 1 confirm that this is a highly elongated object and strongly suggest that it's bifurcated. An Arecibo CW spectrum is available here. The Minor Planet Center has classified 2010 LE15 as a "Potentially Hazardous Asteroid."
Orbital and Physical Characteristics Provisional Designation 2010 LE15 Asteroid number 398188 Discoverer WISE Discovery date 2010 orbit type Aten Close approach dist. 0.0399 AU Close approach dist. 15.5 lunar distances Close approach date 2014 Aug 12 semimajor axis 0.865 AU eccentricity 0.273 inclination 13.3 deg perihelion distance 0.629 AU aphelion distance 1.101 AU Tisserand parameter 6.778 --> not remotely cometary absolute magnitude (H) 19.5 diameter 0.44 km (Mainzer et al. 2011, based on WISE spacecraft results) optical albedo 0.15 (Mainzer et al. 2011, based on WISE spacecraft results) rotation period ~20 h; possible non-principal axis rotator (B. D. Warner, J. Pollock, pers. comm.) pole direction unknown lightcurve amplitude 0.8 mag (B. D. Warner, pers. comm.) spectral class S (M. D. Hicks, pers. comm.) Last update: 2014 August 14
2010 LE15 http://www.minorplanetcenter.net/mpec/K10/K10L56.html
GOLDSTONE SNRS Assumptions: D = 0.44 km, P = 20 h, OC radar albedo = 0.1 w DOY start date window RA, dec dist runs SNR/day SNR/run 30 208 2014 Jul 27 06:12-16:28 358, +17 0.093 197 28 2 31 209 2014 Jul 28 06:16-16:27 0, +16 0.089 207 35 3 31 210 2014 Jul 29 06:20-16:26 1, +15 0.084 217 43 3 31 211 2014 Jul 30 06:25-16:25 3, +13 0.079 227 55 4 31 212 2014 Jul 31 06:32-16:25 4, +12 0.074 239 69 5 31 213 2014 Aug 01 06:40-16:24 6, +11 0.070 251 89 6 31 214 2014 Aug 02 06:49-16:24 8, +9 0.065 263 110 8 31 215 2014 Aug 03 07:00-16:24 11, +7 0.061 275 150 10 32 216 2014 Aug 04 07:14-16:24 13, +4 0.057 288 190 12 32 217 2014 Aug 05 07:30-16:24 17, +1 0.053 299 240 15 32 218 2014 Aug 06 07:50-16:24 20, -2 0.050 307 310 19 32 219 2014 Aug 07 08:13-16:23 24, -5 0.047 312 390 24 32 220 2014 Aug 08 08:42-16:22 29, -9 0.044 310 460 29 32 221 2014 Aug 09 09:17-16:21 34, -14 0.042 299 520 33 Scheduled 32 222 2014 Aug 10 09:58-16:17 40, -19 0.041 276 540 35 Cancelled due to equipment problems 33 223 2014 Aug 11 10:48-16:11 46, -24 0.040 238 500 35 Scheduled 33 224 2014 Aug 12 11:49-16:00 53, -28 0.040 185 410 32 Scheduled 33 225 2014 Aug 13 13:06-15:37 61, -32 0.041 109 280 27 Scheduled Goldstone SNRs assume Ptx = 450 kW and Tsys = 17 K. ARECIBO SNRS start date window RA, dec dist runs SNR/day SNR/run 2014 Jul 20 06:37-09:23 351, +21 0.130 38 43 7 2014 Jul 21 06:36-09:22 352, +20 0.125 40 51 8 2014 Jul 22 06:36-09:22 353, +20 0.119 41 60 10 2014 Jul 23 06:35-09:22 354, +19 0.114 42 70 11 2014 Jul 24 06:35-09:22 355, +19 0.109 42 82 13 2014 Jul 25 06:36-09:22 356, +18 0.104 44 99 15 2014 Jul 26 06:36-09:22 357, +18 0.099 48 120 18 2014 Jul 27 06:37-09:22 358, +17 0.094 53 150 22 2014 Jul 28 06:39-09:23 359, +16 0.089 55 190 27 2014 Jul 29 06:42-09:24 1, +15 0.084 57 240 32 2014 Jul 30 06:45-09:25 2, +14 0.080 60 300 40 2014 Jul 31 06:50-09:26 4, +12 0.075 63 370 49 Scheduled...cancelled 2014 Aug 01 06:56-09:27 6, +11 0.070 64 470 61 Scheduled...completed 2014 Aug 02 07:04-09:28 8, +9 0.066 66 590 76 Scheduled...cancelled 2014 Aug 03 07:15-09:28 10, +7 0.062 65 730 97 Scheduled...cancelled 2014 Aug 04 07:30-09:26 13, +5 0.058 60 870 120 2014 Aug 05 07:52-09:21 16, +2 0.054 50 880 140 2014 Aug 06 08:37-08:54 20, -1 0.050 9 370 120 Arecibo SNRs assume Ptx = 400 kW and Tsys = 25 K.
Track Assignments
DOY BOA BOT EOT EOA 221 0920 1050 1620 1650 DSS-14 GSSR AST 2010 LE15 222 0830 1000 1335 1355 DSS-14 GSSR AST 2010 LE15 223 0935 1105 1430 1500 DSS-14 GSSR AST 2010 LE15 224 1200 1330 1600 1630 DSS-14 GSSR AST 2010 LE15 225 1140 1310 1455 1525 DSS-14 GSSR AST 2010 LE15 Goldstone tracks: UT UT PDT Duration Round-trip DOY Date TX Window TX Window hh:mm time (sec) 221 Aug 9 0950-1620 0250-0850 Aug 9 6:30 42 222 Aug 10 1005-1335 0305-0635 Aug 10 3:30 41 223 Aug 11 1100-1430 0400-0730 Aug 11 3:30 40 224 Aug 12 1230-1600 0530-0900 Aug 12 3:30 40 225 Aug 13 1310-1455 0610-0755 Aug 13 1:45 41 Short transmit window Start times indicate when we can transmit, which is often less than 90 minutes after we get the telescope. Arecibo tracks: UT UT PDT Round-trip Date TX Window TX Window time (sec) Jul 31 0650-0926 2350-0226 Jul 30-31 75 Cancelled Aug 1 0656-0927 2356-0227 Jul 31-Aug 1 70 Successful Aug 2 0704-0928 0004-0228 Aug 2 66 Cancelled due to tropical storm Bertha Aug 3 0715-0928 0015-0228 Aug 3 62 Cancelled due to equipment problems
Uncertainties
JPL/Horizons solution 44, #obs = 197 (2001-2014), including 1 Doppler and 1 delay from Arecibo: Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig 2014-Aug-01 00:00 *m 5.24787 11.33226 0.07202052892589 0.625 0.21 0.78 0.000003 2014-Aug-02 00:00 *m 7.28061 9.65332 0.06755606856977 0.693 0.21 0.78 0.000005 2014-Aug-03 00:00 *m 9.55167 7.71740 0.06324823337408 0.770 0.22 0.82 0.000013 2014-Aug-04 00:00 *m 12.10227 5.48207 0.05913078882903 0.857 0.25 0.92 0.000020 2014-Aug-05 00:00 *m 14.98079 2.90151 0.05524556986100 0.954 0.30 1.10 0.000029 2014-Aug-06 00:00 *m 18.24322 -0.06949 0.05164399316313 1.061 0.37 1.35 0.000040 2014-Aug-07 00:00 *m 21.95246 -3.46773 0.04838815843377 1.174 0.46 1.67 0.000052 2014-Aug-08 00:00 * 26.17587 -7.30847 0.04555076237803 1.289 0.56 2.05 0.000068 2014-Aug-09 00:00 * 30.97946 -11.56653 0.04321263455392 1.397 0.67 2.43 0.000087 2014-Aug-10 00:00 * 36.41710 -16.15503 0.04145655892295 1.487 0.77 2.78 0.000109 2014-Aug-11 00:00 * 42.51361 -20.91135 0.04035678886426 1.548 0.84 3.04 0.000135 2014-Aug-12 00:00 * 49.24263 -25.60447 0.03996579269900 1.572 0.87 3.16 0.000162 2014-Aug-13 00:00 * 56.50545 -29.97316 0.04030255861892 1.558 0.86 3.13 0.000190 2014-Aug-14 00:00 * 64.12252 -33.78608 0.04134778946309 1.512 0.82 2.98 0.000217 2014-Aug-15 00:00 * 71.84976 -36.89632 0.04304852270894 1.447 0.76 2.76 0.000242 - - - - - - - - - - JPL/Horizons solution 38, #obs: 171 (2001-2014): Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig 2014-Jul-25 00:00 *m 355.37137 18.43181 0.10590784375405 0.741 0.48 1.75 0.000706 2014-Jul-26 00:00 *m 356.45298 17.76439 0.10088221401894 0.790 0.48 1.75 0.000693 2014-Jul-27 00:00 *m 357.61948 17.00872 0.09590080867737 0.845 0.48 1.75 0.000680 2014-Jul-28 00:00 *m 358.88326 16.15132 0.09097214981964 0.907 0.48 1.76 0.000668 2014-Jul-29 00:00 *m 0.25895 15.17611 0.08610633581398 0.979 0.49 1.78 0.000655 2014-Jul-30 00:00 *m 1.76391 14.06386 0.08131546065847 1.060 0.50 1.83 0.000642 2014-Jul-31 00:00 *m 3.41872 12.79166 0.07661415559745 1.153 0.52 1.90 0.000629 2014-Aug-01 00:00 *m 5.24789 11.33221 0.07202028520955 1.259 0.55 2.02 0.000616 2014-Aug-02 00:00 *m 7.28064 9.65326 0.06755583294450 1.382 0.60 2.18 0.000602 2014-Aug-03 00:00 *m 9.55172 7.71734 0.06324800654292 1.523 0.67 2.42 0.000587 2014-Aug-04 00:00 *m 12.10232 5.48200 0.05913057169807 1.685 0.76 2.75 0.000572 2014-Aug-05 00:00 *m 14.98086 2.90142 0.05524536359145 1.869 0.87 3.18 0.000554 2014-Aug-06 00:00 *m 18.24330 -0.06958 0.05164379922298 2.076 1.02 3.71 0.000536 2014-Aug-07 00:00 *m 21.95256 -3.46784 0.04838797863260 2.304 1.20 4.36 0.000515 2014-Aug-08 00:00 * 26.17599 -7.30860 0.04555059885428 2.546 1.40 5.10 0.000493 2014-Aug-09 00:00 * 30.97960 -11.56667 0.04321248966894 2.788 1.61 5.87 0.000470 2014-Aug-10 00:00 * 36.41728 -16.15518 0.04145643501659 3.008 1.81 6.57 0.000449 2014-Aug-11 00:00 * 42.51381 -20.91150 0.04035668786579 3.180 1.95 7.09 0.000430 2014-Aug-12 00:00 * 49.24285 -25.60462 0.03996571567631 3.282 2.01 7.31 0.000417 2014-Aug-13 00:00 * 56.50570 -29.97329 0.04030250543949 3.301 1.97 7.18 0.000413 2014-Aug-14 00:00 * 64.12279 -33.78619 0.04134775873468 3.240 1.85 6.73 0.000417 2014-Aug-15 00:00 * 71.85004 -36.89640 0.04304851203089 3.117 1.67 6.06 0.000428 ********************************************************************************************** Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination: JPL/Horizons solution 38 Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta APmag S-O-T /r T-O-M/Illu% 2014-Jul-20 00:00 350.91398 20.80195 0.13145276080784 17.37 114.6568 /L 44.1/ 40.5 2014-Jul-21 00:00 351.70171 20.43714 0.12629748083509 17.28 115.1433 /L 54.8/ 30.5 2014-Jul-22 00:00 352.53478 20.02600 0.12115832952876 17.18 115.6231 /L 65.7/ 21.6 2014-Jul-23 00:00 353.41890 19.56263 0.11603956437302 17.07 116.0941 /L 76.7/ 14.1 2014-Jul-24 00:00 354.36067 19.04009 0.11094598432505 16.97 116.5533 /L 87.6/ 8.0 2014-Jul-25 00:00 355.36780 18.45028 0.10588304525102 16.85 116.9970 /L 98.4/ 3.6 2014-Jul-26 00:00 356.44928 17.78362 0.10085700990864 16.74 117.4205 /L 109.2/ 1.0 2014-Jul-27 00:00 357.61566 17.02876 0.09587514186279 16.62 117.8176 /L 119.9/ 0.2 2014-Jul-28 00:00 358.87936 16.17220 0.09094595609801 16.50 118.1801 /L 130.5/ 1.2 2014-Jul-29 00:00 0.25501 15.19787 0.08607954320191 16.37 118.4976 /L 141.1/ 3.9 2014-Jul-30 00:00 1.75998 14.08655 0.08128798884786 16.24 118.7561 /L 151.6/ 8.3 2014-Jul-31 00:00 3.41487 12.81529 0.07658591571430 16.11 118.9375 /L 162.0/ 14.3 2014-Aug-01 00:00 5.24423 11.35677 0.07199118016651 15.97 119.0179 /L 171.4/ 21.6 2014-Aug-02 00:00 7.27730 9.67873 0.06752575886347 15.84 118.9659 /L 172.2/ 30.1 2014-Aug-03 00:00 9.54887 7.74362 0.06321685599981 15.70 118.7411 /L 162.9/ 39.6 2014-Aug-04 00:00 12.10021 5.50891 0.05909823992092 15.57 118.2913 /L 152.1/ 49.8 2014-Aug-05 00:00 14.97980 2.92870 0.05521175918585 15.44 117.5517 /L 140.7/ 60.3 2014-Aug-06 00:00 18.24370 -0.04238 0.05160886132270 15.32 116.4445 /L 129.2/ 70.6 2014-Aug-07 00:00 21.95495 -3.44130 0.04835170209368 15.23 114.8832 /L 117.5/ 80.3 2014-Aug-08 00:00 26.18104 -7.28350 0.04551306727448 15.16 112.7827 /L 106.0/ 88.7 2014-Aug-09 00:00 30.98810 -11.54389 0.04317391139121 15.12 110.0782 /L 95.0/ 95.1 2014-Aug-10 00:00 36.43012 -16.13555 0.04141716967643 15.13 106.7517 /L 85.1/ 98.9 2014-Aug-11 00:00 42.53189 -20.89556 0.04031724416817 15.20 102.8584 /L 77.0/ 99.8 2014-Aug-12 00:00 49.26689 -25.59237 0.03992670394497 15.32 98.5370 /L 71.2/ 97.5 2014-Aug-13 00:00 56.53602 -29.96410 0.04026454820947 15.49 93.9914 /L 67.9/ 92.5 2014-Aug-14 00:00 64.15910 -33.77895 0.04131138991972 15.72 89.4455 /L 66.7/ 85.1 2014-Aug-15 00:00 71.89137 -36.88989 0.04301410522465 15.97 85.0934 /L 66.7/ 76.1 2014-Aug-16 00:00 79.46619 -39.25687 0.04529752976715 16.25 81.0667 /L 67.1/ 66.0 2014-Aug-17 00:00 86.64779 -40.93140 0.04807785798926 16.54 77.4300 /L 67.3/ 55.5 2014-Aug-18 00:00 93.26996 -42.01984 0.05127331674649 16.83 74.1942 /L 66.9/ 45.2 2014-Aug-19 00:00 99.24759 -42.64638 0.05481049091983 17.11 71.3365 /L 65.8/ 35.3 2014-Aug-20 00:00 104.56487 -42.92777 0.05862686572331 17.38 68.8169 /L 64.2/ 26.2
Setups
Given the estimated diameter and the lower bound on the rotation period, we're expecting a bandwidth of about 2-3 Hz. We're going to start with a standard setup and then adjust it as necessary: CW setup: --------------------------------------------------------------------------- TX polarization RCP RCV polarization LCP & RCP Frequency hops: no hopping Bandwidth: 4000 Hz TXoffset +500 Hz Sampling interval: 2500 x 0.1 usec FFT for PFS files: 16384 for 0.24 Hz resolution Ranging setups: --------------------------------------------------------------------------- 10-usec baud 10 usec code 127 PRP 1270 usec FFT 128 ncoh 1 bandwidth 787 Hz resolution 12.3 Hz TXOFF +100Hz (echo in bin 32 + 8 = 40) --------------------------------------------------------------------------- 11-usec baud 11 usec code 127 PRP 1397 usec FFT 64 ncoh 1 bandwidth 716 Hz resolution 11.2 Hz TXOFF +100 Hz (echo in bin 32 + 9= 41) ------------------------------------------------------------------------- 1-usec baud 1 usec code 255 FFT 512 ncoh 16 bandwidth 245 Hz resolution 0.48 Hz TXOFF +50 Hz ---------------------------------------------------------------------
Instructions
NOTE: Data should be moved to the appropriate subdirectories in aardvark:/export/data0/2010le15/raw/
POINTING:
OSOD and predicts will be on aardvark: ...not available yet... POINTING TX Offsets Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD ... to be added ... Transmit offsets are given in millidegrees.
PRDX.OUT.14f-14-14.?? TRANSMITTER: STATION #14, RECEIVER: STATION #14 RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
2010 LE15 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/2010LE15/2010LE15_planning.html
Asteroid Radar Astronomy