Goldstone Radar Observations Planning: 1991 VK
7341 1991 VK 1991 VK was observed on three previous occasions with radar. The first was in January 1997 (CW and ranging, Ostro et al., 1998), the second was in January of 2007, and the third was in January 2012. This object has a 4.2-h rotation period (Pravec et al., 1998) and is ~1.4 km in diameter. To date, the best resolution achieved by radar was 1 usec (150 m). The periodic close approaches make it a good candidate for detecting the Yarkovsky effect. 1991 VK will approach Earth at 25 lunar distances (LD) on Jan. 25, 2017, and we will observe it at Goldstone in the week prior to the closest approach. 1991 VK will be a relatively weak target at Goldstone, although we expect to obtain some 1 usec (150 m) images. This object will also be observed at Arecibo on Jan. 4-5, where we hope to image it with finer resolution. All of the Goldstone observations occur after 1991 VK moves too far south for Arecibo to track. 1991 VK is classified as a Potentially Hazardous Asteroid.
Orbital and Physical Characteristics Provisional Designation 1991 VK Asteroid number 7341 Discoverer Eleanor F. Helin, Kenneth J. Lawrence from Palomar Observatory Discovery date 1991 Nov 01 orbit type Apollo Close approach date 2017 January 25 Close approach dist. 0.0647 au Close approach dist. 25 lunar distances semimajor axis 1.842 au eccentricity 0.507 inclination 5.4 deg perihelion distance 0.909 au aphelion distance 2.775 au Tisserand parameter 3.846 absolute magnitude (H) 16.7 diameter 1.4 km (Arecibo radar images) optical albedo 0.2 rotation period 4.2 h (Pravec et al. 1998) lightcurve amplitude 0.28-0.70 (Pravec et al., 1998) pole direction unknown spectral class Sq, Sr (Binzel et al., 2002; Lazzarin et al., 2004) Last update: 2017 January 4
First IAU circular Circular No. 5392 Central Bureau for Astronomical Telegrams INTERNATIONAL ASTRONOMICAL UNION Postal Address: Central Bureau for Astronomical Telegrams Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A. Telephone 617-495-7244/7440/7444 (for emergency use only) TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505 MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN 1991 VK E. Helin and K. Lawrence (and the latter should also have been credited with the discovery of 1991 VE on IAUC 5385) have discovered another fast-moving asteroidal object with the 0.46-m Palomar Schmidt, with assistance also from P. Rose: 1991 UT R.A. (1950) Decl. Mag. Nov. 1.16337 23 45 14.30 +25 09 34.2 15.5 1.19132 23 45 09.47 +25 09 28.6 2.19063 23 42 28.72 +25 05 28.6 4.21823 23 37 02.41 +24 55 56.0 Preliminary orbital elements from the above observations by B. G. Marsden, Harvard-Smithsonian Center for Astrophysics: T = 1992 Jan. 7.780 ET Peri. = 173.254 e = 0.50349 Node = 294.423 1950.0 q = 0.91076 AU Incl. = 5.390 a = 1.83431 AU n = 0.396731 P = 2.48 years 1991 ET R.A. (1950) Decl. Delta r V Nov. 20 22 56.88 +22 51.5 0.206 1.092 14.8 25 22 44.92 +21 58.6 30 22 32.69 +20 58.8 0.173 1.032 14.7 Dec. 5 22 19.40 +19 48.3 10 22 03.75 +18 19.3 0.138 0.981 14.7 15 21 43.68 +16 15.9 20 21 16.12 +13 08.3 0.102 0.942 15.2 25 20 37.07 + 8 08.8 30 19 43.57 + 0 31.3 0.076 0.918 18.3 1991 November 21 (5392) Daniel W. E. Green
1991 VK Goldstone SNRs Assumptions: D = 1.4 km, P = 4.2 h, OC radar albedo = 0.1 w DOY start date window RA, dec dist runs SNR/day SNR/run 02 8 2017 JAN 08 18:29-02:59 332.6, -2 0.1098 139 31 3 02 9 2017 JAN 09 18:24-02:49 331.7, -3 0.1055 143 36 3 02 10 2017 JAN 10 18:19-02:34 330.7, -4 0.1013 146 41 3 02 11 2017 JAN 11 18:14-02:24 329.6, -5 0.0972 151 49 4 02 12 2017 JAN 12 18:14-02:09 328.4, -7 0.0932 153 57 5 02 13 2017 JAN 13 18:09-01:54 327.0, -9 0.0894 156 66 5 02 14 2017 JAN 14 18:04-01:34 325.5,-10 0.0858 157 76 6 03 15 2017 JAN 15 18:04-01:19 323.8,-12 0.0823 158 88 7 03 16 2017 JAN 16 17:59-00:54 321.9,-15 0.0791 157 101 8 Scheduled 03 17 2017 JAN 17 17:59-00:34 319.8,-17 0.0762 155 115 9 Scheduled 03 18 2017 JAN 18 17:59-00:09 317.5,-19 0.0735 151 128 10 03 19 2017 JAN 19 17:59-23:39 314.9,-22 0.0711 143 139 12 03 20 2017 JAN 20 17:59-23:04 312.0,-25 0.0691 132 148 13 03 21 2017 JAN 21 18:04-22:29 308.8,-27 0.0675 118 152 14 04 22 2017 JAN 22 18:14-21:44 305.3,-30 0.0662 95 146 15 Scheduled 04 23 2017 JAN 23 18:34-20:44 301.6,-33 0.0653 59 120 16 Goldstone SNRs assume Ptx = 450 kW. Arecibo SNRs start date window RA, dec dist runs SNR/day SNR/run 2016 DEC 07 20:40-23:15 339, 10 0.2461 18 5 19 2016 DEC 08 20:35-23:10 339, 10 0.2427 19 5 21 2016 DEC 09 20:30-23:05 339, 10 0.2392 19 5 22 2016 DEC 10 20:25-23:05 339, 10 0.2356 20 5 24 2016 DEC 11 20:25-23:00 339, 10 0.2320 20 6 25 2016 DEC 12 20:20-22:55 339, 9 0.2283 20 6 26 2016 DEC 13 20:15-22:50 339, 9 0.2245 20 6 28 2016 DEC 14 20:10-22:45 339, 9 0.2207 21 7 30 2016 DEC 15 20:10-22:40 339, 9 0.2168 20 7 31 2016 DEC 16 20:05-22:35 339, 9 0.2128 21 8 34 2016 DEC 17 20:00-22:30 339, 8 0.2088 21 8 37 2016 DEC 18 19:55-22:25 339, 8 0.2047 22 9 40 2016 DEC 19 19:55-22:25 339, 8 0.2006 22 9 43 2016 DEC 20 19:50-22:20 338, 8 0.1964 22 10 47 2016 DEC 21 19:45-22:15 338, 8 0.1921 23 11 51 2016 DEC 22 19:45-22:10 338, 7 0.1878 23 12 56 2016 DEC 23 19:40-22:05 338, 7 0.1834 23 13 60 2016 DEC 24 19:35-22:00 338, 7 0.1790 24 14 67 2016 DEC 25 19:30-21:50 338, 6 0.1746 24 15 73 2016 DEC 26 19:30-21:45 338, 6 0.1701 23 16 79 2016 DEC 27 19:25-21:40 338, 6 0.1656 24 18 88 2016 DEC 28 19:20-21:35 337, 5 0.1611 25 20 99 2016 DEC 29 19:20-21:30 337, 5 0.1565 24 22 107 2016 DEC 30 19:15-21:20 337, 4 0.1519 24 24 119 2016 DEC 31 19:10-21:15 337, 4 0.1473 25 27 135 2017 JAN 01 19:10-21:05 336, 3 0.1427 24 30 148 2017 JAN 02 19:05-21:00 336, 3 0.1381 25 34 169 2017 JAN 03 19:05-20:50 335, 2 0.1336 23 38 182 2017 JAN 04 19:00-20:40 335, 1 0.1290 23 43 206 Scheduled 2017 JAN 05 19:00-20:30 334, 1 0.1244 21 49 223 Scheduled 2017 JAN 06 19:00-20:15 334, 0 0.1199 18 55 235 2017 JAN 07 19:05-20:00 333, 0 0.1155 14 63 236 Assumptions: Ptx = 1000 kW, Tsys = 23 K
Track Assignments
DOY BOA BOT EOT EOA 016 1830 2000 2200 2230 017 1640 1810 2115 2145 022 1905 2035 2140 2210 Goldstone Schedule: UT Target UT PST Round-trip Asteroid OBSERVER DOY Date TX Window TX Window time (sec) SNR/RTT 016 Jan 16 1991 VK 1900-2200 1100-1400 Jan 16 79 8 017 Jan 17 1991 VK 1810-2115 1010-1315 Jan 17 76 9 022 Jan 22 1991 VK 1935-2140 1135-1340 Jan 22 66 15 Arecibo Schedule: 2017 Jan 04-05
Uncertainties
1991 VK JPL solution #256 Soln.date: 2017-Jan-02_06:18:16 # obs: 1349 (1991-2016) Date__(UT)__HR:MN POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig ************************************************************************ 2017-Jan-01 00:00 *m 0.084 0.02 0.08 0.000027 2017-Jan-02 00:00 *m 0.085 0.02 0.08 0.000026 2017-Jan-03 00:00 *m 0.087 0.02 0.08 0.000026 2017-Jan-04 00:00 *m 0.089 0.02 0.08 0.000025 2017-Jan-05 00:00 *m 0.092 0.02 0.08 0.000025 2017-Jan-06 00:00 *m 0.094 0.02 0.08 0.000024 2017-Jan-07 00:00 *m 0.097 0.02 0.08 0.000023 2017-Jan-08 00:00 *m 0.101 0.02 0.08 0.000023 2017-Jan-09 00:00 *m 0.104 0.02 0.09 0.000022 2017-Jan-10 00:00 *m 0.108 0.02 0.09 0.000022 2017-Jan-11 00:00 *m 0.113 0.03 0.09 0.000021 2017-Jan-12 00:00 * 0.117 0.03 0.10 0.000021 2017-Jan-13 00:00 * 0.122 0.03 0.10 0.000020 2017-Jan-14 00:00 * 0.128 0.03 0.11 0.000019 2017-Jan-15 00:00 * 0.134 0.03 0.11 0.000019 2017-Jan-16 00:00 * 0.140 0.03 0.12 0.000018 2017-Jan-17 00:00 * 0.147 0.04 0.13 0.000018 2017-Jan-18 00:00 * 0.154 0.04 0.14 0.000017 2017-Jan-19 00:00 * 0.161 0.04 0.15 0.000017 2017-Jan-20 00:00 * 0.168 0.04 0.16 0.000016 2017-Jan-21 00:00 * 0.174 0.04 0.16 0.000016 2017-Jan-22 00:00 * 0.180 0.05 0.17 0.000015 2017-Jan-23 00:00 * 0.186 0.05 0.17 0.000015 2017-Jan-24 00:00 * 0.190 0.05 0.18 0.000015 2017-Jan-25 00:00 * 0.194 0.05 0.17 0.000015 2017-Jan-26 00:00 * 0.196 0.05 0.17 0.000016 2017-Jan-27 00:00 *m 0.197 0.04 0.16 0.000016 2017-Jan-28 00:00 *m 0.197 0.04 0.15 0.000017 2017-Jan-29 00:00 *m 0.196 0.04 0.14 0.000017 2017-Jan-30 00:00 *m 0.194 0.04 0.13 0.000018 2017-Jan-31 00:00 *m 0.191 0.03 0.12 0.000018 ********************************************************************************************** Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination: 1991 VK Date__(UT)__HR:MN R.A._(a-appar)_DEC. APmag delta S-O-T /r T-O-M/Illu% ******************************************************************************************** 2017-Jan-01 00:00 *m 337.22819 4.37175 16.60 0.14675359546237 60.6836 /T 31.2/ 7.0 2017-Jan-02 00:00 *m 336.88415 3.80556 16.65 0.14213052088154 59.1197 /T 19.9/ 13.1 2017-Jan-03 00:00 *m 336.49597 3.18905 16.70 0.13750815971928 57.4908 /T 13.1/ 21.1 2017-Jan-04 00:00 *m 336.05867 2.51674 16.77 0.13289430261872 55.7896 /T 18.1/ 30.5 2017-Jan-05 00:00 *m 335.56669 1.78259 16.85 0.12829755441483 54.0086 /T 29.8/ 41.0 2017-Jan-06 00:00 *m 335.01384 0.97987 17. 0.12372743825215 52.1390 /T 43.5/ 52.2 2017-Jan-07 00:00 *m 334.39324 0.10119 17. 0.11919451044732 50.1715 /T 58.0/ 63.6 2017-Jan-08 00:00 *m 333.69715 -0.86159 17. 0.11471048442292 48.0959 /T 73.1/ 74.4 2017-Jan-09 00:00 *m 332.91695 -1.91734 17. 0.11028836047594 45.9012 /T 88.6/ 83.9 2017-Jan-10 00:00 *m 332.04300 -3.07561 18. 0.10594255732493 43.5756 /T 104.4/ 91.7 2017-Jan-11 00:00 *m 331.06453 -4.34658 18. 0.10168904219149 41.1070 /T 120.4/ 97.0 2017-Jan-12 00:00 * 329.96946 -5.74083 18. 0.09754545834615 38.4830 /T 136.4/ 99.6 2017-Jan-13 00:00 * 328.74434 -7.26912 18. 0.09353125014240 35.6919 /T 152.4/ 99.5 2017-Jan-14 00:00 * 327.37409 -8.94188 19. 0.08966778161875 32.7238 /T 168.2/ 96.7 2017-Jan-15 00:00 * 325.84191 -10.76861 19. 0.08597843310593 29.5724 /T 175.7/ 91.8 2017-Jan-16 00:00 * 324.12915 -12.75689 20. 0.08248864216924 26.2385 /T 160.6/ 85.1 2017-Jan-17 00:00 * 322.21528 -14.91120 21. 0.07922583530759 22.7372 /T 145.4/ 77.1 2017-Jan-18 00:00 * 320.07796 -17.23130 22. 0.07621918058075 19.1126 /T 130.4/ 68.3 2017-Jan-19 00:00 * 317.69340 -19.71037 23. 0.07349908374971 15.4718 /T 115.5/ 59.0 2017-Jan-20 00:00 * 315.03708 -22.33296 25. 0.07109635736472 12.0781 /T 100.6/ 49.6 2017-Jan-21 00:00 * 312.08486 -25.07319 27. 0.06904102110873 9.5780 /T 85.8/ 40.3 2017-Jan-22 00:00 * 308.81485 -27.89342 28. 0.06736074966612 9.1487 /T 71.0/ 31.4 2017-Jan-23 00:00 * 305.21002 -30.74425 26. 0.06607907144092 11.2986 /L 56.3/ 23.1 2017-Jan-24 00:00 * 301.26167 -33.56611 23. 0.06521352241920 15.0982 /L 42.0/ 15.6 2017-Jan-25 00:00 * 296.97351 -36.29289 21. 0.06477404076799 19.6657 /L 29.2/ 9.3 2017-Jan-26 00:00 * 292.36586 -38.85740 20. 0.06476190660389 24.5675 /L 21.2/ 4.5 2017-Jan-27 00:00 *m 287.47890 -41.19781 19. 0.06516945869747 29.5861 /L 23.9/ 1.3 2017-Jan-28 00:00 *m 282.37382 -43.26408 18. 0.06598066463367 34.5930 /L 35.1/ 0.0 2017-Jan-29 00:00 *m 277.13046 -45.02278 17. 0.06717243476627 39.5030 /L 49.2/ 0.9 2017-Jan-30 00:00 *m 271.84130 -46.45954 17. 0.06871642285356 44.2584 /L 64.4/ 4.1 2017-Jan-31 00:00 *m 266.60238 -47.57856 16. 0.07058099658409 48.8214 /L 79.8/ 9.5
Setups
We're going to start with a standard CW setup, which should work fine: CW setup: --------------------------------------------------------------------------- TX polarization RCP RCV polarization LCP & RCP Frequency hops: no hopping Bandwidth: 5000 Hz TXoffset +500 Hz Sampling interval: 2500 x 0.1 usec FFT for PFS files: 10000 for 0.5 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 +100 Hz (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/data0/1991vk/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 ... not available yet... 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
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/1991VK/1991VK_planning.2017.html
Asteroid Radar Astronomy