(7341) 1991 VK Goldstone Radar Observations Planning
(7341) 1991 VK was discovered by Eleanor F. Helin and Kenneth J. Lawrence on November 1, 1991 from Palomar Observatory. 1991 VK is a PHA that we previously observed on two occasions with radar. The first was in January 1997 with Goldstone (CW and ranging, Ostro et al., 1998) and the second was in January of 2007 with Arecibo. 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). 1991 VK approaches Earth at 25 lunar distances (LD) on Jan. 25, 2012, 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. 4-6, where we hope to image it with 0.2 usec (30 m) resolution. All of the Goldstone observations occur after 1991 VK moves too far south for Arecibo to track. 1991 VK becomes a day-time object in early January, and it becomes observable again with optical telescopes in the southern hemisphere in the second part of February.
Orbital and Physical Characteristics orbit type Apollo semimajor axis 1.842 AU eccentricity 0.507 inclination 5.422 deg perihelion distance 0.909 AU aphelion distance 2.776 AU absolute magnitude (H) 16.7 diameter 1.4 km (Arecibo radar images) rotation period 4.2 h (Pravec et al., 1998) pole direction unknown lightcurve amplitude 0.28-0.70 (Pravec et al., 1998) spectral class Sq, Sr (Binzel et al., 2002; Lazzarin et al., 2004) Last update: 2012 Jan 21
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
Target Name: (7341) 1991 VK
D = 1.4 km
Period = 4.2 h
OC albedo = 0.1
# max
start date window RA, dec dist runs SNR SNR/run
-----------------------------------------------------------------------
2012 Jan 10 18:25-02:41 331, -4 0.104 156 41 4
2012 Jan 11 18:21-02:28 330, -5 0.100 159 47 4
2012 Jan 12 18:18-02:14 329, -6 0.096 163 55 5
2012 Jan 13 18:14-01:59 328, -8 0.092 167 64 6
2012 Jan 14 18:11-01:43 326, -10 0.088 170 73 6
2012 Jan 15 18:08-01:25 325, -11 0.085 172 84 7
2012 Jan 16 18:05-01:05 323, -13 0.081 173 96 8
2012 Jan 17 18:03-00:44 321, -16 0.078 174 110 9
2012 Jan 18 18:01-00:19 319, -18 0.075 172 120 10
2012 Jan 19 18:01-23:52 316, -21 0.073 169 130 11
2012 Jan 20 18:01-23:22 313, -23 0.071 164 140 12
2012 Jan 21 18:04-22:47 310, -26 0.069 155 140 13
2012 Jan 22 18:09-22:06 307, -29 0.067 144 140 13
2012 Jan 23 18:22-21:17 303, -31 0.066 128 130 13
2012 Jan 24 18:56-20:02 299, -34 0.065 107 120 12
Goldstone SNRs assume Ptx = 450 kW
Goldstone tracks:
UT UT PST Duration Round-trip
DOY Date TX Window TX Window hh:mm time (sec) SNR/Run
--- ---- --------- --------- --------- --------- -------
015 Jan 15/16 2045-0105 1245-1705 Jan 15 04:20 84 7
017 Jan 17 2100-2330 1300-1530 Jan 17 02:30 78 9
020 Jan 20 2050-2320 1250-1520 Jan 20 03:00 70 12
022 Jan 22 1815-2205 1015-1405 Jan 22 03:50 67 13 Cancelled. DSS-14 code RED.
TXON is listed at the earliest time we can start to transmit, even if that occurs before
the end of precal.
Scheduled Arecibo tracks:
UT UT AST PST Duration Round-trip
DOY Date TX Window TX Window TX Window hh:mm time (sec) SNR/Run
--- ---- --------- --------- --------- --------- ---------- ---------
004 Jan 04 1908-2041 1508-1641 Jan 04 1108-1241 Jan 04 01:33 131 43
005 Jan 05 1906-2030 1506-1630 Jan 05 1106-1230 Jan 05 01:24 126 46
006 Jan 06 1906-2019 1506-1619 Jan 06 1106-1219 Jan 06 01:13 122 48
From Jon Giorgini, Jan 11 2012, Solution #166, #obs 892 (1991-2012), radar at 3 apparations Date__(UT)__HR:MN POS_3sigma DOP_X_3sig RT_delay_3sig 2012-Jan-15 00:00 0.396 0.47 0.000030 2012-Jan-16 00:00 0.414 0.52 0.000035 2012-Jan-17 00:00 0.431 0.57 0.000040 2012-Jan-18 00:00 0.448 0.62 0.000045 2012-Jan-19 00:00 0.464 0.67 0.000052 2012-Jan-20 00:00 0.478 0.71 0.000058 2012-Jan-21 00:00 0.490 0.74 0.000066 2012-Jan-22 00:00 0.498 0.76 0.000073 2012-Jan-23 00:00 0.503 0.76 0.000081 From JPL Horizons, Dec 02 2011, Solution #155, #obs 876 (1991-2011) ******************************************************************************* Date__(UT)__HR:MN POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig 2012-Jan-05 00:00 *m 0.556 0.14 0.51 0.000278 2012-Jan-06 00:00 *m 0.586 0.16 0.58 0.000274 2012-Jan-07 00:00 *m 0.619 0.18 0.65 0.000268 2012-Jan-08 00:00 *m 0.655 0.20 0.74 0.000262 2012-Jan-09 00:00 * 0.694 0.23 0.83 0.000256 2012-Jan-10 00:00 * 0.737 0.26 0.94 0.000248 2012-Jan-11 00:00 * 0.782 0.29 1.06 0.000239 2012-Jan-12 00:00 * 0.831 0.33 1.19 0.000229 2012-Jan-13 00:00 * 0.884 0.37 1.34 0.000218 2012-Jan-14 00:00 * 0.941 0.41 1.50 0.000206 2012-Jan-15 00:00 * 1.000 0.46 1.67 0.000193 2012-Jan-16 00:00 * 1.063 0.51 1.86 0.000178 2012-Jan-17 00:00 * 1.127 0.57 2.07 0.000161 2012-Jan-18 00:00 * 1.193 0.63 2.28 0.000144 2012-Jan-19 00:00 * 1.257 0.69 2.49 0.000126 2012-Jan-20 00:00 * 1.318 0.74 2.69 0.000108 2012-Jan-21 00:00 * 1.373 0.79 2.88 0.000092 2012-Jan-22 00:00 * 1.420 0.84 3.04 0.000082 2012-Jan-23 00:00 *m 1.455 0.87 3.15 0.000082 2012-Jan-24 00:00 *m 1.476 0.88 3.21 0.000092 2012-Jan-25 00:00 *m 1.482 0.88 3.20 0.000110 ****************************************************************************************** Apparent Magnitudes and Solar Elongations: Date__(UT)__HR:MN R.A._(J2000.0)_DEC. APmag delta S-O-T /r 2011-Dec-12 00:00 * 339.24076 10.24316 16.35 0.23316948422827 85.6370 /T 2011-Dec-13 00:00 * 339.20620 10.08042 16.35 0.22949955473375 84.5696 /T 2011-Dec-14 00:00 * 339.17131 9.91265 16.35 0.22576193824278 83.4984 /T 2011-Dec-15 00:00 * 339.13509 9.73903 16.35 0.22195755772171 82.4219 /T 2011-Dec-16 00:00 * 339.09650 9.55869 16.35 0.21808753138107 81.3388 /T 2011-Dec-17 00:00 * 339.05446 9.37070 16.35 0.21415315785983 80.2478 /T 2011-Dec-18 00:00 * 339.00783 9.17404 16.36 0.21015590306365 79.1473 /T 2011-Dec-19 00:00 * 338.95540 8.96762 16.36 0.20609738987222 78.0359 /T 2011-Dec-20 00:00 * 338.89590 8.75027 16.36 0.20197939262315 76.9116 /T 2011-Dec-21 00:00 * 338.82798 8.52070 16.37 0.19780383929294 75.7728 /T 2011-Dec-22 00:00 * 338.75015 8.27749 16.38 0.19357282497982 74.6175 /T 2011-Dec-23 00:00 * 338.66082 8.01912 16.38 0.18928863964002 73.4435 /T 2011-Dec-24 00:00 * 338.55823 7.74387 16.39 0.18495381032162 72.2483 /T 2011-Dec-25 00:00 *m 338.44045 7.44986 16.41 0.18057115391364 71.0295 /T 2011-Dec-26 00:00 *m 338.30539 7.13500 16.42 0.17614383280285 69.7840 /T 2011-Dec-27 00:00 *m 338.15074 6.79698 16.43 0.17167540523357 68.5088 /T 2011-Dec-28 00:00 *m 337.97397 6.43324 16.45 0.16716986524926 67.2003 /T 2011-Dec-29 00:00 *m 337.77234 6.04095 16.48 0.16263167203619 65.8546 /T 2011-Dec-30 00:00 *m 337.54285 5.61696 16.50 0.15806577259278 64.4675 /T 2011-Dec-31 00:00 *m 337.28221 5.15781 16.54 0.15347762340135 63.0344 /T 2012-Jan-01 00:00 *m 336.98684 4.65966 16.57 0.14887321640607 61.5502 /T 2012-Jan-02 00:00 *m 336.65280 4.11824 16.62 0.14425911319275 60.0092 /T 2012-Jan-03 00:00 *m 336.27576 3.52884 16.67 0.13964248977278 58.4053 /T 2012-Jan-04 00:00 *m 335.85094 2.88626 16.73 0.13503119321760 56.7316 /T 2012-Jan-05 00:00 *m 335.37306 2.18472 16.80 0.13043381062058 54.9807 /T 2012-Jan-06 00:00 *m 334.83625 1.41786 n.a. 0.12585975032154 53.1444 /T 2012-Jan-07 00:00 *m 334.23400 0.57865 n.a. 0.12131933493512 51.2137 /T 2012-Jan-08 00:00 *m 333.55907 -0.34058 n.a. 0.11682390544345 49.1789 /T 2012-Jan-09 00:00 * 332.80339 -1.34821 n.a. 0.11238593551077 47.0294 /T 2012-Jan-10 00:00 * 331.95793 -2.45330 n.a. 0.10801915527812 44.7539 /T 2012-Jan-11 00:00 * 331.01263 -3.66549 n.a. 0.10373868397912 42.3405 /T 2012-Jan-12 00:00 * 329.95622 -4.99493 n.a. 0.09956117019737 39.7771 /T 2012-Jan-13 00:00 * 328.77609 -6.45203 n.a. 0.09550493648403 37.0515 /T 2012-Jan-14 00:00 * 327.45815 -8.04706 n.a. 0.09159012034438 34.1527 /T 2012-Jan-15 00:00 * 325.98666 -9.78967 n.a. 0.08783879566416 31.0720 /T 2012-Jan-16 00:00 * 324.34413 -11.68809 n.a. 0.08427504757890 27.8058 /T 2012-Jan-17 00:00 * 322.51125 -13.74803 n.a. 0.08092496047515 24.3598 /T 2012-Jan-18 00:00 * 320.46691 -15.97135 n.a. 0.07781646492815 20.7592 /T 2012-Jan-19 00:00 * 318.18850 -18.35430 n.a. 0.07497897784426 17.0691 /T 2012-Jan-20 00:00 * 315.65235 -20.88567 n.a. 0.07244276593750 13.4508 /T 2012-Jan-21 00:00 * 312.83469 -23.54482 n.a. 0.07023797376432 10.3150 /T 2012-Jan-22 00:00 * 309.71321 -26.30021 n.a. 0.06839329337552 8.6366 /T 2012-Jan-23 00:00 *m 306.26924 -29.10862 n.a. 0.06693431997458 9.5806 /T 2012-Jan-24 00:00 *m 302.49085 -31.91603 n.a. 0.06588173242267 12.7705 /L 2012-Jan-25 00:00 *m 298.37664 -34.66011 n.a. 0.06524953620529 17.0792 /L
We are expecting a bandwidth of about 30 Hz, and the Doppler uncertainties are
small, so we will start with a standard CW setup to verify that we have echoes:
CW setup:
---------------------------------------------------------------------------
TX polarization RCP
RCV polarization LCP & RCP
Frequency hops: 2
Dwell 20 seconds
Bandwidth: 4000 Hz
Sampling interval: 2500 x 0.1 usec
VME FFT for PSD files: 1024 for 3.9 Hz resolution
Ranging setups:
---------------------------------------------------------------------------
127 x 64 10-usec single sample
baud 10 usec
code 127
gates 127
PRP 1270 usec
FFT 64
CLT VME ?
PFS ?
ncoh 1
bandwidth 787 Hz
resolution 12.3 Hz
TXOFF +150 Hz -> echo will be centered at +12 bins or in bin 32 + 12 = 44
---------------------------------------------------------------------------
127 x 64 11-usec single sample
baud 11 usec
code 127
gates 127
PRP 1397 usec
FFT 64
CLT VME ?
PFS ?
ncoh 1
bandwidth 717 Hz
resolution 11.2 Hz
TXOFF +150 Hz --> echo will be centered at +13 bins or in bin 32 + 13 =45
-------------------------------------------------------------------------
1-usec coarse imaging
----------------------------
baud 1 usec
code 127 (so that VME can display it)
ncoh 12
bandwidth 656 Hz
FFT 128
resolution 5.1 Hz
TXoff +100 Hz (echo in bin 64+20 =84)
_____________________________________________________________________
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:
/export/apps0/temp_data/data3/osod/ops/a7341/PRDX.OUT.14f-14-14.s170
/PUNCH.OUT.14f-14-14.s170
/EPH.OUT.s170
POINTING
TX Offsets
Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
2012 01 22 022 180000 307.3899 -28.3674 A 67.1
2012 01 22 022 190000 307.2350 -28.4865 A 67.1
2012 01 22 022 200000 307.0787 -28.6047 A 2.90 -2.20 67.0 s170
2012 01 22 022 210000 306.9217 -28.7220 A 66.9
2012 01 22 022 220000 306.7646 -28.8382 A 66.9
Transmit offsets are given in millidegrees.
PRDX.OUT.14f-14-14.s170
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
2012 JAN 22 18:00 67.1185126051 145046.268 327.2214 -28.3674 307.390 19.113
2012 JAN 22 18:10 67.1083808925 144042.011 329.7539 -28.3873 307.364 20.103
2012 JAN 22 18:20 67.0983202368 143019.026 332.2865 -28.4072 307.338 21.024
2012 JAN 22 18:30 67.0883318994 141978.776 334.8192 -28.4270 307.313 21.875
2012 JAN 22 18:40 67.0784170381 140922.761 337.3519 -28.4469 307.287 22.651
2012 JAN 22 18:50 67.0685767042 139852.510 339.8846 -28.4667 307.261 23.351
2012 JAN 22 19:00 67.0588118416 138769.578 342.4174 -28.4865 307.235 23.972
2012 JAN 22 19:10 67.0491232841 137675.546 344.9502 -28.5063 307.209 24.511
2012 JAN 22 19:20 67.0395117534 136572.015 347.4830 -28.5260 307.183 24.968
2012 JAN 22 19:30 67.0299778580 135460.605 350.0159 -28.5457 307.157 25.339
2012 JAN 22 19:40 67.0205220943 134342.950 352.5488 -28.5654 307.131 25.624
2012 JAN 22 19:50 67.0111448411 133220.695 355.0818 -28.5851 307.105 25.821
2012 JAN 22 20:00 67.0018463642 132095.495 357.6147 -28.6047 307.079 25.930
2012 JAN 22 20:10 66.9926268107 130969.008 0.1477 -28.6243 307.053 25.950
2012 JAN 22 20:20 66.9834862137 129842.896 2.6807 -28.6439 307.026 25.880
2012 JAN 22 20:30 66.9744244876 128718.817 5.2137 -28.6635 307.000 25.722
2012 JAN 22 20:40 66.9654414331 127598.427 7.7467 -28.6830 306.974 25.476
2012 JAN 22 20:50 66.9565367327 126483.372 10.2797 -28.7025 306.948 25.143
2012 JAN 22 21:00 66.9477099562 125375.287 12.8128 -28.7220 306.922 24.725
2012 JAN 22 21:10 66.9389605568 124275.794 15.3458 -28.7414 306.896 24.222
2012 JAN 22 21:20 66.9302878768 123186.497 17.8788 -28.7608 306.869 23.637
2012 JAN 22 21:30 66.9216911464 122108.977 20.4119 -28.7802 306.843 22.972
2012 JAN 22 21:40 66.9131694842 121044.795 22.9449 -28.7996 306.817 22.230
2012 JAN 22 21:50 66.9047219019 119995.482 25.4779 -28.8189 306.791 21.413
2012 JAN 22 22:00 66.8963473046 118962.541 28.0109 -28.8382 306.765 20.524
2012 JAN 22 22:10 66.8880444930 117947.441 30.5439 -28.8575 306.739 19.566
2012 JAN 22 22:20 66.8798121660 116951.616 33.0769 -28.8768 306.712 18.541
1991VK 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 300-233 | FAX: (818) 354-9476
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.html
Asteroid Radar Astronomy