2005 WJ56 Planning


Background

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.

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          unknown
 pole direction           unknown
 lightcurve amplitude     unknown
 spectral class           X    (M. D. Hicks, personal communication)

Last update: 2008 January 02

Discovery



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


SNR Calculation

HMag:           17.8
Diameter:       0.87 km  (an educated guess assuming H = 17.8 and an S-class optical albedo)
Period:         4        (an 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      -

Track Assignments


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
008  Jan 09  0150-0346   1750-1946 Jan 08   02:04      29          4200  Monostatic 
009  Jan 10  0059-0342   1659-1942 Jan 09   02:43      28          5400  Receive at Greenbank/Lynn Carter, PI
010  Jan 11  0048-0303   1648-1903 Jan 10   02:15      28          5300  Receive at Greenbank/Lynn Carter, PI


Uncertainties

From Horizons, 2007 November 15: JPL/Horizons solution 6, #obs = 57 (9 days)

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

Setups


Plans for January 13:

WE WILL START WITH SOLUTION ??

We will start with a standard CW setup, get echoes, and then go to 1/8 usec imaging
as soon as possible.  We don't know the rotation period or the bandwidth, so the
setup below is a placeholder; we'll update plans after we get echoes at Arecibo
on January 9.

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:  4096 for 1.22-Hz resolution  

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 
______________________________________________________________________


Instructions

NOTE: Data should be moved to the appropriate subdirectories in stealth:/export/data0/rosema/2005WJ56/raw/

2005 WJ56 POINTING:

OSOD and predicts will be at Goldstone on stealth soon:

/export/data3/osod/ops/2005wj56/ PRDX.OUT.s??
                               /PUNCH.OUT.s??
                                 /EPH.OUT.s??

POINTING  
                                                  TX Offsets    
Date (UTC)   DOY  hhmmss    RA       Dec   Macro  LHA      Dec      RTT    OSOD


NOT AVAILABLE YET



PRDX.OUT.s?? TRANSMITTER: STATION #14, RECEIVER: STATION #14 RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL NOT AVAILABLE YET

2005 WJ56 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@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