2005 WJ56 Planning
2005 WJ56 was discovered by LINEAR on November 29, 2005. It will approach within 0.0279 AU (10.9 lunar distances) on January 10 when it will be a very strong radar target. Goldstone observations are scheduled on January 13 and Arecibo observations are scheduled on January 9-11. Note that Goldstone observations straddle the January 12-13 date boundary; we can start setting up late on Jan. 12 and begin transmitting at 01:15Z on Jan. 13 (5:15 PM, Saturday, January 12, Pacific Time). Given its absolute magnitude of 17.8, 2005 WJ56 has a diameter that is probably within a factor of two of 870 meters. Otherwise, we know nothing about its physical properties, but given recent experience, there's a ~1/6 chance that it's a binary object. This object will brighten to about 12th magnitude in mid-January when it will be a good target for photometric and spectroscopic observations. Due to its diameter and the proximity of its orbit to Earth, 2005 WJ56 has been classified as a "Potentially Hazardous Asteroid" by the Minor Planet Center.
Orbital and Physical Characteristics orbit type Apollo semimajor axis 0.959 AU eccentricity 0.152 inclination 21.6° perihelion distance 0.813 AU aphelion distance 1.105 AU absolute magnitude (H) 17.8 diameter 870 meters +- a factor of two rotation period slow; days? pole direction unknown lightcurve amplitude unknown spectral class X (M. D. Hicks, personal communication) Last update: 2008 January 14
M.P.E.C. 2005-W96 Issued 2005 Nov. 30, 20:52 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.
Supported in part by the Brinson Foundation
Supported in part by the TABASGO Foundation
Prepared using the Tamkin Foundation Computer Network
MPC@CFA.HARVARD.EDU
URL http://cfa-www.harvard.edu/iau/mpc.html ISSN 1523-6714
2005 WJ56
Observations:
K05W56J* C2005 11 29.06634 21 06 35.20 +22 49 00.3 19.3 EW096704
K05W56J C2005 11 29.07910 21 06 38.05 +22 49 00.2 20.0 EW096704
K05W56J C2005 11 29.09316 21 06 41.11 +22 49 00.6 19.7 EW096704
K05W56J C2005 11 29.10634 21 06 44.01 +22 49 00.3 19.5 EW096704
K05W56J C2005 11 29.11922 21 06 46.88 +22 49 01.2 19.7 EW096704
K05W56J C2005 11 30.04695 21 10 16.99 +22 49 40.0 18.9 R EW096711
K05W56J C2005 11 30.05168 21 10 18.11 +22 49 39.6 EW096711
K05W56J C2005 11 30.05657 21 10 19.20 +22 49 39.8 19.1 R EW096711
K05W56J C2005 11 30.06836 21 10 21.90 +22 49 39.4 19.6 V EW096G96
K05W56J C2005 11 30.06946 21 10 22.15 +22 49 39.6 19.6 V EW096G96
K05W56J C2005 11 30.80025 21 13 07.75 +22 50 00.3 19.4 EW096147
K05W56J C2005 11 30.80532 21 13 08.87 +22 50 00.6 19.2 EW096147
K05W56J C2005 11 30.80968 21 13 09.85 +22 50 00.8 19.3 EW096147
Observer details:
147 Osservatorio Astronomico di Suno. Observers D. Crespi, S. Foglia,
G. Galli, S. Minuto, V. Sacco. Measurer S. Foglia. 0.40-m f/4 reflector
+ CCD.
704 Lincoln Laboratory ETS, New Mexico. Observers M. Bezpalko, L. Manguso,
D. Torres, R. Kracke, A. Milner, H. Love. Measurers J. Stuart, R. Sayer,
J. Evans, J. Kommers. 1.0-m f/2.15 reflector + CCD.
711 McDonald Observatory. Observer J. G. Ries. 0.76-m reflector + CCD
+ prime-focus corrector.
G96 Mt. Lemmon Survey. Observers A. D. Grauer, E. C. Beshore. Measurers
E. C. Beshore, E. J. Christensen, G. J. Garradd, A. D. Grauer, R. E. Hill,
R. A. Kowalski, S. M. Larson, R. H. McNaught. 1.5-m reflector + CCD.
Orbital elements:
2005 WJ56 PHA 0.025D
Epoch 2006 Mar. 6.0 TT = JDT 2453800.5 MPC
M 265.64275 (2000.0) P Q
n 1.02803153 Peri. 299.51546 -0.62562761 +0.69222479
a 0.9722958 Node 287.10772 -0.51930991 -0.71366115
e 0.1444872 Incl. 22.11069 -0.58215747 -0.10729681
P 0.96 H 17.5 G 0.15 U 9
Residuals in seconds of arc
051129 704 0.7+ 0.2+ 051130 711 0.4- 0.3+ 051130 147 0.5+ 0.4-
051129 704 1.0+ 0.2- 051130 711 0.5+ 0.2- 051130 147 0.3+ 0.2-
051129 704 0.2+ 0.2- 051130 711 0.6+ 0.1- 051130 147 0.3+ 0.1-
051129 704 0.1- 0.8- 051130 G96 0.5+ 0.6-
051129 704 0.0 0.2- 051130 G96 0.5+ 0.5-
Ephemeris:
2005 WJ56 a,e,i = 0.97, 0.14, 22 q = 0.8318
Date TT R. A. (2000) Decl. Delta r Elong. Phase V
2005 11 26 20 55.10 +22 46.3 0.645 1.108 82.7 62.1 19.0
2005 12 06 21 32.96 +22 51.3 0.663 1.112 82.4 61.4 19.0
2005 12 16 22 11.81 +22 44.7 0.680 1.113 81.7 61.1 19.1
2005 12 26 22 51.35 +22 25.9 0.699 1.110 80.6 61.0 19.1
2006 01 05 23 31.27 +21 54.6 0.719 1.103 79.1 61.1 19.2
2006 01 15 00 11.14 +21 10.5 0.741 1.094 77.3 61.3 19.2
2006 01 25 00 50.53 +20 12.8 0.763 1.081 75.2 61.7 19.3
2006 02 04 01 29.17 +19 01.5 0.786 1.065 72.9 62.2 19.3
2006 02 14 02 06.77 +17 36.3 0.807 1.047 70.6 62.8 19.4
2006 02 24 02 43.17 +15 56.8 0.825 1.026 68.1 63.6 19.4
2006 03 06 03 18.32 +14 03.2 0.839 1.003 65.8 64.5 19.4
2006 03 16 03 52.17 +11 55.2 0.847 0.978 63.6 65.6 19.4
2006 03 26 04 24.75 +09 33.2 0.847 0.953 61.6 67.0 19.4
Timothy B. Spahr (C) Copyright 2005 MPC M.P.E.C. 2005-W96
HMag: 17.8
Diameter: 0.87 km (an educated guess assuming H = 17.8 and an S-class optical albedo)
Period: 4 (a standard guess)
------------GOLDSTONE---------- -------------ARECIBO-----------
Max Max
Dat Run UTC Dat Run UTC
Date RA Decl Delta Runs SNR SNR Window Runs SNR SNR Window
2008 1 1 140 69 0.070 512 130 7 1:42-19:23 0 0 0 -
2008 1 2 134 68 0.064 524 190 10 1:23-18:41 0 0 0 -
2008 1 3 127 67 0.058 540 280 14 1:06-17:53 0 0 0 -
2008 1 4 120 65 0.052 557 410 20 0:54-17:06 0 0 0 -
2008 1 5 112 62 0.046 574 630 30 0:42-16:06 0 0 0 -
2008 1 6 104 58 0.041 589 990 45 0:30-15:05 0 0 0 -
2008 1 7 97 52 0.036 601 1500 69 0:24-14:05 0 0 0 -
2008 1 8 90 44 0.032 606 2300 100 0:18-13:00 0 0 0 -
2008 1 9 83 34 0.030 596 3200 140 0:24-12:00 92 35000 4200 2:00- 3:42
2008 1 10 78 22 0.028 562 3700 170 0:30-11:05 140 60000 5400 1:06- 3:47
2008 1 11 73 9 0.028 503 3500 170 0:42-10:05 121 54000 5300 0:54- 3:12
2008 1 12 68 -4 0.030 425 2500 140 0:54- 9:05 0 0 0 -
2008 1 13 65 -14 0.033 342 1500 93 1:18- 8:05 0 0 0 -
2008 1 14 62 -22 0.037 264 820 56 1:42- 7:05 0 0 0 -
2008 1 15 59 -29 0.042 193 420 33 2:17- 6:05 0 0 0 -
2008 1 16 56 -34 0.047 130 210 19 3:23- 4:30 0 0 0 -
2008 1 17 54 -38 0.053 64 91 12 - 0 0 0 -
Arecibo radar observations have revealed that 2005 WJ56 is a very slow rotator,
so the actual SNRs will be significantly stronger than estimated above.
2005 WJ56 Goldstone Schedule
UT UT PST Duration Round-trip
DOY Date TX Window TX Window hh:mm time (sec) SNR/Run
--- ---- --------- --------- ------- --------- -------
013 Jan 13 0115-0445 1715-2045 Jan 12 03:30 33 93
Arecibo Schedule
009 Jan 09 0150-0346 1750-1946 Jan 08 02:04 29 4200 Monostatic
010 Jan 10 0059-0342 1659-1942 Jan 09 02:43 28 5400 Receive at Greenbank (Lynn Carter)
011 Jan 11 0048-0303 1648-1903 Jan 10 02:15 28 5300 Receive at Greenbank (Lynn Carter)
From Horizons, 2008 January 2: Date__(UT)__HR:MN R.A._(J2000.0)_DEC. delta POS_3sigma DOP_X-sig RT_delay-sig 2008-Jan-06 00:00 104.19525 58.25660 0.041201495649004 1.66585899 2.17 0.000491 2008-Jan-07 00:00 96.65208 52.39627 0.036454071827114 2.15171084 1.99 0.000474 2008-Jan-08 00:00 89.61584 44.41648 0.032471456843606 2.80710613 1.74 0.000439 2008-Jan-09 00:00 83.24301 34.10209 0.029561438165218 3.58134070 1.41 0.000382 2008-Jan-10 00:00 77.59330 21.81799 0.028055080166223 4.27685464 1.07 0.000305 2008-Jan-11 00:00 72.65314 8.74864 0.028172200482952 4.61760009 0.90 0.000240 2008-Jan-12 00:00 68.36543 -3.55004 0.029886425555370 4.50075407 1.05 0.000236 2008-Jan-13 00:00 64.65383 -14.01694 0.032941537879625 4.07941543 1.32 0.000289 2008-Jan-14 00:00 61.43847 -22.39897 0.036998869790209 3.56530101 1.56 0.000357 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - From Jon Giorgini, 2008 January 3: 2005 WJ56 solution #66 was estimated based on 282 optical measurements (2005-Nov-29 to 2008-Jan-3). Formal 3-sigma X-band uncertainties are as follows: Date__(UT)__HR:MN POS_3sigma DOP_X-sig RT_delay-sig 2008-Jan-12 00:00 4.20288455 1.04 0.000194 2008-Jan-13 00:00 3.86170091 1.30 0.000229 2008-Jan-14 00:00 3.40951460 1.54 0.000291 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - From Jon Giorgini, 2008 January 8: With new data reported (now 322 optical measurements, 2005-Nov-29 to 2008-Jan-7), 2005 WJ56 solution #74 was computed. Formal 3-sigma X-band uncertainties are shown below. OSOD and nominal predicts have been updated on aardvark. Date__(UT)__HR:MN POS_3sigma DOP_X-sig RT_delay-sig 2008-Jan-09 00:00 1.66224726 1.23 0.000301 2008-Jan-10 00:00 2.18422562 0.99 0.000261 2008-Jan-11 00:00 2.56347542 0.91 0.000210 2008-Jan-12 00:00 2.67623675 1.06 0.000167 2008-Jan-13 00:00 2.56374796 1.28 0.000153 2008-Jan-14 00:00 2.34278056 1.48 0.000169
Arecibo radar observations have revealed that 2005 WJ56 is a very slow rotator.
The maximum bandwidth seen at Arecibo is about 0.4 Hz (when adjusted from S-band to X-band),
so let's start with the following setup in order to resolve the echo in
Doppler frequency:
Initial CW setup
----------------
TX polarization RCP
RCV polarization LCP & RCP
Frequency hops: 2
Dwell 10 seconds
Bandwidth: 4000 Hz
Sampling interval: 2500 x 0.1 usec
VME FFT for PSD files: 32768 for 0.122-Hz resolution (We'll get one FFT per hop).
Possible 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 787.4 Hz
resolution 12.3 Hz
TXOFF +100 Hz -> echo will be centered at +8 bins or in bin 32 + 8 = 40
---------------------------------------------------------------------------
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 715.8 Hz
resolution 11.2 Hz
TXOFF +100 Hz --> echo will be centered at +9 bins or in bin 32 + 9 = 41
-------------------------------------------------------------------------
127 x 64 7-usec single sample
baud 7 usec
code 127
gates 127
PRP 889
FFT 64
CLT VME ?
PFS ?
ncoh 1
bandwidth 1124.9 Hz
resolution 17.6 Hz
TXOFF +60 -> echo would be centered at +3.4 bins w/perfect ephemeris
-------------------------------------------------------------------------
127 x 64 1-usec single sample
baud 1 usec
code 127
gates 127
PRP 127
FFT 64
CLT 4
ncoh 15
bandwidth 525 Hz
resolution 8.2 Hz
TXOFF +100 -> echo would be centered at +12.2 bins or in bin 32 + 12.2 = 44
-------------------------------------------------------------------------------
0.125-usec ranging
setup JX1XS001 revised
baud 0.125 usec
code 127
gates 127
FFT 64
ncoh 984
bandwidth 64.016384 Hz
resolution 1.000256 Hz
TXOFF +15 Hz to put echo at 32 + 15 = bin 47
PFS CLT gate ?
VME CLT gate ?
_______________________________________________________________________
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 at Goldstone on aardvark:
/export/home0/jongi/ops/2005wj56/ PRDX.OUT.s78
/PUNCH.OUT.s78
/EPH.OUT.s78
The files are also available to download from:
http://echo.jpl.nasa.gov/asteroids/2005WJ56/PRDX.OUT.s78
http://echo.jpl.nasa.gov/asteroids/2005WJ56/PUNCH.OUT.s78
http://echo.jpl.nasa.gov/asteroids/2005WJ56/EPH.OUT.s78
POINTING
TX Offsets
Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
2008 01 13 013 010000 64.6019 -14.3914 A 33.0 78
2008 01 13 013 020000 64.4481 -14.7809 A 33.2
2008 01 13 013 030000 64.2924 -15.1660 A 0.0014 -0.0036 33.3
2008 01 13 013 040000 64.1359 -15.5465 A 33.5
2008 01 13 013 050000 63.9797 -15.9223 A 33.6
PRDX.OUT.s78
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
2008 JAN 13 01:10 33.0413910138 -345444.147 307.9403 -14.4567 64.576 19.904
2008 JAN 13 01:20 33.0656478636 -346717.665 310.4727 -14.5218 64.551 21.511
2008 JAN 13 01:30 33.0899950127 -348020.595 313.0052 -14.5867 64.525 23.072
2008 JAN 13 01:40 33.1144344747 -349351.685 315.5377 -14.6516 64.500 24.585
2008 JAN 13 01:50 33.1389681781 -350709.624 318.0703 -14.7163 64.474 26.046
2008 JAN 13 02:00 33.1635979567 -352093.047 320.6029 -14.7809 64.448 27.450
2008 JAN 13 02:10 33.1883255508 -353500.536 323.1356 -14.8454 64.422 28.794
2008 JAN 13 02:20 33.2131525888 -354930.623 325.6683 -14.9098 64.396 30.073
2008 JAN 13 02:30 33.2380806088 -356381.795 328.2011 -14.9740 64.370 31.283
2008 JAN 13 02:40 33.2631110304 -357852.493 330.7339 -15.0382 64.344 32.419
2008 JAN 13 02:50 33.2882451699 -359341.118 333.2668 -15.1022 64.318 33.477
2008 JAN 13 03:00 33.3134842232 -360846.035 335.7997 -15.1660 64.292 34.452
2008 JAN 13 03:10 33.3388292734 -362365.573 338.3326 -15.2298 64.266 35.340
2008 JAN 13 03:20 33.3642812859 -363898.031 340.8655 -15.2934 64.240 36.135
2008 JAN 13 03:30 33.3898411093 -365441.681 343.3984 -15.3569 64.214 36.835
2008 JAN 13 03:40 33.4155094630 -366994.770 345.9314 -15.4202 64.188 37.434
2008 JAN 13 03:50 33.4412869501 -368555.525 348.4643 -15.4834 64.162 37.929
2008 JAN 13 04:00 33.4671740417 -370122.156 350.9972 -15.5465 64.136 38.318
2008 JAN 13 04:10 33.4931710863 -371692.859 353.5302 -15.6095 64.110 38.597
2008 JAN 13 04:20 33.5192783059 -373265.822 356.0631 -15.6723 64.084 38.766
2008 JAN 13 04:30 33.5454957985 -374839.224 358.5960 -15.7350 64.058 38.822
2008 JAN 13 04:40 33.5718235311 -376411.244 1.1289 -15.7976 64.032 38.765
2008 JAN 13 04:50 33.5982613359 -377980.060 3.6618 -15.8600 64.006 38.597
2005 WJ56 GOLDSTONE MASTERLOG
==============================================================================
Receive TX
Setup hops dwell code ncoh FFT runs start -stop OSOD offset Poln Notes
------------------------------------------------------------------------------
PSD2008013.208.2005WJ56
PSD2008013.209.2005WJ56
PSD2008013.212.2005WJ56
PSD2008013.214.2005WJ56
CW, 4 kHz 2 10 16384 26 014326-021215 78 none RCP Ephemeris is bad
CW, 4 kHz 2 10 16384 8 021656-022523 76 none RCP Ephemeris is bad
PSD2008013.216.2005WJ56, VOLT2008013.217.2005WJ56
CW, 4 kHz 2 10 16384 10 022726-023809 78 none RCP
1/8 usec 127 1970 512 48 031011-040402 78 +8 RCP
1/8 usec 127 7382 256 34 040646-044444 78 +1 RCP
==============================================================================
Dr. Lance A. M. Benner | PHONE: (818) 354-7412
Mail Stop 300-233 | FAX: (818) 354-9476
Jet Propulsion Laboratory | email: lance@reason.jpl.nasa.gov
Pasadena, CA 91109-8099 | Plan: To live long and prosper
http://echo.jpl.nasa.gov/asteroids/2005WJ56/2005WJ56_planning.html
Asteroid Radar Astronomy