2005 GC120 Goldstone Radar Observations Planning


Background


2005 GC120 was discovered on April 12, 2005 by the Catalina Sky Survey in Arizona. 
This object has an absolute magnitude of 19.6, suggesting a diameter within a factor of two of 380 meters.
2005 GC120 has eccentric (e~0.5) and inclined (i~16.5 deg) orbit that crosses orbits of Venus, Earth, and Mars.

2005 GC120 will approach within 0.043 AU (~16.9 lunar distances) on Dec. 1, 2010, when
it will be a moderate radar target. For optical observations, 2005 GC120 is too close to the Sun until Nov. 29, 
when it emerges as a 17.6 mag object at southern declinations. 

Goldstone radar observations are scheduled on Nov. 30 and Dec. 4.

THE TRACK ON DECEMBER 4 HAS BEEN CANCELLED DUE TO PROBLEMS WITH THE AZIMUTH BEARING.

2005 GC120 has been classified as a "Potentially Hazardous Asteroid" by the 
Minor Planet Center.
Orbital and Physical Characteristics  
 orbit type               Apollo
 semimajor axis           1.193 AU     
 eccentricity             0.497
 inclination              16.5       
 perihelion distance      0.599 AU     
 aphelion distance        1.787 AU     
 absolute magnitude (H)   19.6
 diameter                 0.38 km   (plus/minus a factor of two)
 rotation period          unknown
 pole direction           unknown  
 lightcurve amplitude     unknown
 spectral class           unknown 

Last update: 2010 Dec 02

First MPEC

 M.P.E.C. 2005-G87                                Issued 2005 Apr. 13, 10:51 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
             Prepared using the Tamkin Foundation Computer Network

                              MPC@CFA.HARVARD.EDU
          URL http://cfa-www.harvard.edu/iau/mpc.html  ISSN 1523-6714

                                  2005 GC120

Observations:
     K05GC0C* C2005 04 12.31682 13 23 42.73 +39 59 02.6          20.0 R EG087703
     K05GC0C  C2005 04 12.32518 13 23 40.81 +39 59 15.0          19.7 R EG087703
     K05GC0C  C2005 04 12.33353 13 23 38.70 +39 59 25.7          19.2 R EG087703
     K05GC0C  C2005 04 12.34177 13 23 36.71 +39 59 37.6          20.2 R EG087703
     K05GC0C  C2005 04 12.89663 13 21 26.45 +40 12 22.5          19.4 R EG087176
     K05GC0C  C2005 04 12.92141 13 21 20.36 +40 12 55.8          19.8 R EG087176
     K05GC0C  C2005 04 12.92451 13 21 19.59 +40 13 00.0          19.5 R EG087176
     K05GC0C  C2005 04 12.92760 13 21 18.83 +40 13 04.2          19.3 R EG087176
     K05GC0C  C2005 04 13.13573 13 20 29.68 +40 17 44.8          19.0 R EG087G90
     K05GC0C  C2005 04 13.14049 13 20 28.51 +40 17 51.6          19.1 R EG087G90
     K05GC0C  C2005 04 13.14524 13 20 27.34 +40 17 58.4          18.8 R EG087G90
     K05GC0C  C2005 04 13.19461 13 20 15.20 +40 19 08.1          19.9 R EG087854
     K05GC0C  C2005 04 13.19844 13 20 14.03 +40 19 13.6          19.8 R EG087854
     K05GC0C  C2005 04 13.20227 13 20 13.20 +40 19 17.3          20.1 R EG087854
     K05GC0C 5C2005 04 13.35451 13 19 35.31 +40 22 45.6          17.0 R EG087673
     K05GC0C 5C2005 04 13.35799 13 19 34.40 +40 22 48.2                 EG087673
     K05GC0C 5C2005 04 13.36493 13 19 32.59 +40 22 57.6                 EG087673
     K05GC0C 5C2005 04 13.36875 13 19 31.61 +40 23 02.6                 EG087673
     K05GC0C 5C2005 04 13.37639 13 19 29.61 +40 23 13.1                 EG087673
     K05GC0C 5C2005 04 13.37917 13 19 29.02 +40 23 16.0                 EG087673

Observer details:
176 Observatori Astronomic de Consell.  Observers A. Lopez, R. Pacheco,
    J. Forteza.  0.41-m f/4 reflector + CCD.
673 Table Mountain Observatory, Wrightwood.  Observer D. Mayes.  0.6-m
    reflector + CCD.
703 Catalina Sky Survey.  Observer S. M. Larson.  Measurers E. C. Beshore,
    C. M. Casey, E. J. Christensen, G. J. Garradd, A. D. Grauer, R. E. Hill,
    S. M. Larson, R. H. McNaught.  0.68-m Schmidt + CCD.
854 Sabino Canyon Observatory, Tucson.  Observer J. E. McGaha.  0.36-m f/10.0
    Schmidt-Cassegrain + CCD.
G90 Three Buttes Observatory, Tucson.  Observer G. R. Jones.  0.40-m
    Ritchey-Chretien + CCD.

Orbital elements:
2005 GC120                                                           PHA 0.014A
Epoch 2005 Mar. 31.0 TT = JDT 2453460.5                 MPC
M 277.54159              (2000.0)            P               Q
n   0.74516410     Peri.  258.61648     +0.79537429     +0.54243231
a   1.2049474      Node    67.98964     -0.37655644     +0.79186703
e   0.5144070      Incl.   16.96087     -0.47495787     +0.28055980
P   1.32           H   19.5           G   0.15
From 20 observations 2005 Apr. 12-13.

Ephemeris:
2005 GC120               a,e,i = 1.20, 0.51, 17                  q = 0.5851
Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase     V
2005 04 10    13 32.40   +39 02.5    0.453    1.351   132.9    32.9    19.8
2005 04 20    12 50.05   +42 24.5    0.406    1.279   124.3    40.5    19.7
2005 04 30    11 58.33   +43 21.7    0.373    1.200   112.5    50.9    19.6
2005 05 10    11 05.03   +41 26.5    0.349    1.117    98.6    63.4    19.7
2005 05 20    10 15.65   +37 01.5    0.330    1.028    83.5    77.9    19.9
2005 05 30    09 28.71   +30 45.3    0.314    0.936    66.9    95.1    20.2

Timothy B. Spahr             (C) Copyright 2005 MPC           M.P.E.C. 2005-G87

SNR Calculation

Target Name:    2005 GC120
HMag:           19.6
Diameter:       0.38 km  (plus/minus a factor of two)
Period:         2.1 h      

                                              #           max
 Start date  UT  window    RA, dec  dist    runs   SNR  SNR/run
----------------------------------------------------------------
2010 Nov 30  00:03-02:11   327, -33  0.045     67     46      6
2010 Nov 30  23:01-04:37   338, -23  0.043    187    100      8
2010 Dec 01  22:41-06:08   348, -12  0.044    246    120      9
2010 Dec 02  22:32-07:12   357,  -2  0.048    269    100      7
2010 Dec 03  22:29-07:59     3,   7  0.054    268     72      5
2010 Dec 04  22:29-08:33     9,  13  0.061    256     45      3  CANCELLED

Goldstone SNRs assume Ptx = 430 kW 

Track Assignments


Goldstone tracks:

        UT          UT          PDT                     Duration  Round-trip
DOY     Date        TX Window   TX Window               hh:mm     time (sec)  SNR/Run 
---     ----        ---------   ---------               --------- -------     -------
335     Dec 01      0030 0435   1630 2035  Nov 30         4:05      43           8
338     Dec 04      0520 0755   2120 2355  Dec 03         2:35      55           3   CANCELLED


Uncertainties

From Jon Giorgini, Nov 27 2010:
Solution #16 was calculated based on 84 optical measurements
(2005-Apr-4 to 2010-Mar-6).
Formal 3-sigma X-band uncertainties:

 Date__(UT)__HR:MN   POS_3sigma   DOP_X_3sig  RT_delay_3sig
 2010-Dec-01 00:00       19.957         4.13       0.008227
 2010-Dec-02 00:00       24.129         4.64       0.007626
 2010-Dec-03 00:00       26.796         6.04       0.006805
 2010-Dec-04 00:00       27.043         7.33       0.005983
 2010-Dec-05 00:00       25.665         8.24       0.005292

From JPL Horizons, Mar 07 2010, Solution #14, #obs 84 (2005-2010 data arc)

 Date__(UT)__HR:MN      POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2010-Nov-30 00:00         16.938        1.46        5.21       0.008301
 2010-Dec-01 00:00         19.843        1.14        4.09       0.008051
 2010-Dec-02 00:00         23.981        1.27        4.53       0.007443
 2010-Dec-03 00:00         26.555        1.64        5.88       0.006627
 2010-Dec-04 00:00         26.730        2.00        7.15       0.005815
 2010-Dec-05 00:00         25.317        2.25        8.05       0.005137
 2010-Dec-06 00:00         23.257        2.41        8.63       0.004623
 2010-Dec-07 00:00         21.104        2.51        8.99       0.004249
 2010-Dec-08 00:00         19.100        2.57        9.19       0.003984


Apparent Magnitudes and Solar Elongations:

 Date__(UT)__HR:MN     R.A._(J2000.0)_DEC.  APmag            delta     S-O-T /r
 2010-Nov-27 00:00     291.29573 -48.87714   n.a. 0.06353083188875   47.5658 /T
 2010-Nov-28 00:00     301.93360 -45.97419   n.a. 0.05600752097128   53.1301 /T
 2010-Nov-29 00:00     313.73785 -41.01038  17.64 0.04980536585133   60.6616 /T
 2010-Nov-30 00:00     325.83552 -33.50368  16.86 0.04545492838132   70.3778 /T
 2010-Dec-01 00:00     337.22301 -23.71296  16.20 0.04350586743277   81.8183 /T
 2010-Dec-02 00:00     347.20499 -12.91849  15.77 0.04427160183250   93.6438 /T
 2010-Dec-03 00:00     355.55629  -2.76157  15.57 0.04762060006589  104.2821 /T
 2010-Dec-04 00:00       2.38531   5.74727  15.55 0.05306851073423  112.8508 /T
 2010-Dec-05 00:00       7.93707  12.43328  15.64 0.06005158833858  119.3043 /T
 2010-Dec-06 00:00      12.47001  17.56313  15.79 0.06810563771218  124.0122 /T
 2010-Dec-07 00:00      16.20671  21.49720  15.97 0.07690233620025  127.4081 /T
 2010-Dec-08 00:00      19.32383  24.54677  16.16 0.08622277306494  129.8519 /T
 2010-Dec-09 00:00      21.95696  26.94652  16.35 0.09592288948710  131.6090 /T
 2010-Dec-10 00:00      24.20904  28.86527  16.54 0.10590712248794  132.8669 /T
 2010-Dec-11 00:00      26.15823  30.42308  16.73 0.11611101946040  133.7571 /T
 2010-Dec-12 00:00      27.86424  31.70574  16.91 0.12649027261053  134.3716 /T
 2010-Dec-13 00:00      29.37307  32.77524  17.08 0.13701384557826  134.7761 /T
 2010-Dec-14 00:00      30.72056  33.67706  17.24 0.14765962096611  135.0177 /T
 2010-Dec-15 00:00      31.93486  34.44505  17.40 0.15841159706084  135.1312 /T

Setups


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:    4096 for 0.98-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              4
bandwidth        196.9 Hz   
resolution       3.1 Hz
TXOFF          +50 Hz -> echo will be centered at +16 bins or in bin 32 + 16 = 48
---------------------------------------------------------------------------
127 x 64 11-usec single sample
baud             11 usec
code            127
gates           127
PRP            1397 usec
FFT              64  
CLT       VME     ?
          PFS     ?
ncoh              4
bandwidth        179.0  Hz   
resolution       2.8  Hz
TXOFF          +50 Hz --> echo will be centered at +18 bins or in bin 32 + 18 = 50
-------------------------------------------------------------------------
1-usec single sample
baud              1 usec
code              127
ncoh              20
bandwidth         393.7  Hz
FFT               128
dfreq             3.1  Hz
TXoff            +50 Hz  (echo in bin 64+16 =80)
-------------------------------------------------------------------------------
0.25-usec imaging  
baud            0.25 usec
code            127
FFT             128
ncoh            246
bandwidth       128 Hz    
resolution      1.00 Hz
TXOFF          +20  Hz, echo is in bin 64+20=84 
--------------------------------------------------------------------------
0.125-usec 
------------ 
baud           0.125 usec
code           255  
FFT            256 
ncoh           122
bandwidth      257.15 Hz      
resolution     1.0045 Hz
TXOFF          +30 Hz to put echo at 128 + 30 = bin 158 

_____________________________________________________________________
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 aardvark:/export/data0/2005GC120/raw/

2005 GC120 POINTING:

  OSOD and predicts are on aardvark:

/export/data3/osod/ops/2005gc120/PRDX.s16 
                              /PUNCH.OUT.s16
                              /EPH.OUT.s16


POINTING  
                                                          TX Offsets    
Date (UTC) DOY hhmmss    RA      Dec         Macro   LHA     Dec    RTT    OSOD
2010 12 01 335 000000 337.3981 -23.7036        A                    43.4
2010 12 01 335 010000 337.8326 -23.2631        A                    43.4
2010 12 01 335 020000 338.2641 -22.8197        A     -5.2    5.4    43.4   s16
2010 12 01 335 030000 338.6934 -22.3736        A                    43.3

2010 12 01 335 030000 338.6934 -22.3736        B                    43.3
2010 12 01 335 040000 339.1212 -21.9251        B     -5.1    5.4    43.3  s16
2010 12 01 335 050000 339.5483 -21.4745        B                    43.3

Transmit offsets are given in millidegrees.  


PRDX.OUT.s16 TRANSMITTER: STATION #14, RECEIVER: STATION #14 RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL 2010 DEC 01 00:00 43.3951371368 68967.564 335.4597 -23.7034 337.398 26.468 2010 DEC 01 00:10 43.3903952097 66332.748 337.8939 -23.6302 337.471 27.343 2010 DEC 01 00:20 43.3858385064 63682.897 340.3282 -23.5569 337.543 28.145 2010 DEC 01 00:30 43.3814680248 61019.383 342.7625 -23.4836 337.616 28.870 2010 DEC 01 00:40 43.3772846737 58343.603 345.1970 -23.4101 337.688 29.516 2010 DEC 01 00:50 43.3732892629 55656.978 347.6316 -23.3366 337.761 30.081 2010 DEC 01 01:00 43.3694825103 52960.951 350.0662 -23.2629 337.833 30.561 2010 DEC 01 01:10 43.3658650156 50256.981 352.5010 -23.1892 337.905 30.956 2010 DEC 01 01:20 43.3624372920 47546.545 354.9358 -23.1155 337.977 31.262 2010 DEC 01 01:30 43.3591997324 44831.133 357.3707 -23.0416 338.049 31.479 2010 DEC 01 01:40 43.3561526332 42112.242 359.8056 -22.9677 338.121 31.606 2010 DEC 01 01:50 43.3532961934 39391.381 2.2407 -22.8937 338.193 31.642 2010 DEC 01 02:00 43.3506304901 36670.061 4.6758 -22.8196 338.264 31.586 2010 DEC 01 02:10 43.3481555025 33949.796 7.1109 -22.7454 338.336 31.440 2010 DEC 01 02:20 43.3458711115 31232.100 9.5462 -22.6712 338.408 31.203 2010 DEC 01 02:30 43.3437770762 28518.482 11.9814 -22.5969 338.479 30.877 2010 DEC 01 02:40 43.3418730659 25810.448 14.4168 -22.5225 338.551 30.463 2010 DEC 01 02:50 43.3401586208 23109.493 16.8521 -22.4480 338.622 29.963 2010 DEC 01 03:00 43.3386332168 20417.100 19.2875 -22.3735 338.694 29.379 2010 DEC 01 03:10 43.3372961782 17734.738 21.7230 -22.2989 338.765 28.714 2010 DEC 01 03:20 43.3361467669 15063.862 24.1585 -22.2243 338.836 27.971 2010 DEC 01 03:30 43.3351841196 12405.903 26.5940 -22.1496 338.908 27.151 2010 DEC 01 03:40 43.3344072893 9762.272 29.0296 -22.0748 338.979 26.258 2010 DEC 01 03:50 43.3338152152 7134.356 31.4652 -21.9999 339.050 25.296 2010 DEC 01 04:00 43.3334067481 4523.513 33.9008 -21.9250 339.121 24.267 2010 DEC 01 04:10 43.3331806445 1931.073 36.3364 -21.8501 339.193 23.174 2010 DEC 01 04:20 43.3331355731 -641.668 38.7721 -21.7750 339.264 22.021 2010 DEC 01 04:30 43.3332701049 -3193.448 41.2078 -21.7000 339.335 20.810 2010 DEC 01 04:40 43.3335827315 -5723.042 43.6434 -21.6248 339.406 19.546 2010 DEC 01 04:50 43.3340718603 -8229.263 46.0791 -21.5496 339.477 18.229 2010 DEC 01 05:00 43.3347357968 -10710.969 48.5148 -21.4744 339.548 16.865

2005GC120 GOLDSTONE MASTERLOG

============================================================================== Receive TX Setup hops dwell code ncoh FFT runs start -stop OSOD offset Poln Notes ------------------------------------------------------------------------------ POINTING TX Offsets Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
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/2005GC120/2005GC120_planning.html

Asteroid Radar Astronomy
*************************************************************************************************************