2005 WC1 Planning
Background
2005 WC1 was discovered by LINEAR on November 21, 2005. It will approach within 0.020 AU
(7.7 lunar distances) on December 14. Its physical properties are unknown, but its
absolute magnitude of 20.5 suggests a diameter within a factor of two of 250 m.
Update on 2005 December 14: Arecibo obseravations this morning revealed a bandwidth of
about 2.5 Hz and a diameter of roughly 300 meters, suggesting a rotation period in the realm
of 3 - 4 hours.
Due to the proximity of its approach and its size, 2005 WC1 will be a strong radar
target. Goldstone observations are scheduled on December 15 in one very short track,
and Arecibo observations are scheduled on December 14.
2005 WC1 has been classified as a "Potentially Hazardous Asteroid" by the International
Astronomical Union's Minor Planet Center.
Orbital and Physical Characteristics
orbit type Apollo
semimajor axis 1.402 AU
eccentricity 0.487
inclination 20.0°
perihelion distance 0.719 AU
aphelion distance 2.085 AU
absolute magnitude (H) 20.5
diameter 250 meters +/- a factor of two
rotation period unknown
pole direction unknown
lightcurve amplitude unknown
spectral class unknown
Last updated: 2005 December 15
Discovery
M.P.E.C. 2005-W36 Issued 2005 Nov. 22, 12:46 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 WC1
Observations:
K05W01C* C2005 11 21.31647 05 52 32.55 +63 13 50.9 18.8 EW036704
K05W01C C2005 11 21.32913 05 52 33.92 +63 14 04.3 19.1 EW036704
K05W01C C2005 11 21.35440 05 52 36.72 +63 14 30.7 19.3 EW036704
K05W01C C2005 11 22.23610 05 54 39.00 +63 29 28.7 19.3 R EW036651
K05W01C C2005 11 22.23978 05 54 39.35 +63 29 33.2 19.3 R EW036651
K05W01C C2005 11 22.24437 05 54 39.99 +63 29 38.1 19.3 R EW036651
K05W01C C2005 11 22.30892 05 54 45.98 +63 30 50.7 18.7 R EW036734
K05W01C C2005 11 22.31479 05 54 46.74 +63 30 56.9 18.5 R EW036734
K05W01C C2005 11 22.31921 05 54 47.21 +63 31 01.2 18.6 R EW036734
K05W01C 5C2005 11 22.45382 05 55 03.89 +63 33 24.0 18.0 R EW036673
K05W01C 5C2005 11 22.46308 05 55 04.91 +63 33 33.2 EW036673
K05W01C 5C2005 11 22.46852 05 55 05.54 +63 33 38.5 EW036673
K05W01C 5C2005 11 22.47245 05 55 05.98 +63 33 42.3 EW036673
Observer details:
651 Grasslands Observatory, Tucson. Observer J. E. McGaha. 0.62-m f/5.1
Newtonian reflector + CCD.
673 Table Mountain Observatory, Wrightwood. Observer J. Young. 0.6-m f/16
Cassegrain + 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.
734 Farpoint Observatory. Observer G. Hug. 0.7-m reflector + CCD.
Orbital elements:
2005 WC1 PHA 0.031
Epoch 2005 Nov. 6.0 TT = JDT 2453680.5 MPC
M 306.79968 (2000.0) P Q
n 0.59785383 Peri. 254.73165 -0.89192527 -0.30996672
a 1.3955306 Node 266.32217 +0.42130618 -0.83408641
e 0.4747118 Incl. 19.26305 -0.16422674 -0.45631184
P 1.65 H 20.4 G 0.15
From 13 observations 2005 Nov. 21-22.
Ephemeris:
2005 WC1 a,e,i = 1.40, 0.47, 19 q = 0.7331
Date TT R. A. (2000) Decl. Delta r Elong. Phase V
2005 11 16 05 41.98 +61 47.7 0.298 1.205 130.7 38.5 19.7
2005 11 17 05 43.82 +62 03.3 0.288 1.197 131.0 38.6 19.6
2005 11 18 05 45.72 +62 19.1 0.277 1.189 131.2 38.7 19.5
2005 11 19 05 47.68 +62 35.2 0.267 1.182 131.4 38.9 19.4
2005 11 20 05 49.71 +62 51.6 0.256 1.174 131.6 39.0 19.3
2005 11 21 05 51.83 +63 08.2 0.246 1.166 131.7 39.2 19.2
2005 11 22 05 54.04 +63 25.2 0.236 1.158 131.9 39.4 19.1
2005 11 23 05 56.38 +63 42.7 0.226 1.151 132.0 39.6 19.0
2005 11 24 05 58.86 +64 00.6 0.215 1.143 132.1 39.9 18.9
2005 11 25 06 01.51 +64 19.1 0.205 1.135 132.1 40.2 18.8
2005 11 26 06 04.37 +64 38.3 0.195 1.127 132.2 40.5 18.7
2005 11 27 06 07.48 +64 58.2 0.185 1.119 132.1 40.8 18.6
2005 11 28 06 10.90 +65 19.0 0.175 1.112 132.1 41.2 18.5
2005 11 29 06 14.69 +65 40.9 0.165 1.104 132.0 41.6 18.3
2005 11 30 06 18.94 +66 04.0 0.155 1.096 131.9 42.1 18.2
2005 12 01 06 23.78 +66 28.6 0.145 1.088 131.7 42.6 18.0
2005 12 02 06 29.37 +66 54.9 0.135 1.080 131.4 43.2 17.9
2005 12 03 06 35.93 +67 23.1 0.126 1.072 131.0 43.9 17.7
2005 12 04 06 43.75 +67 53.7 0.116 1.065 130.5 44.7 17.6
2005 12 05 06 53.27 +68 26.7 0.106 1.057 129.9 45.6 17.4
2005 12 06 07 05.13 +69 02.4 0.0963 1.049 129.2 46.7 17.2
2005 12 07 07 20.27 +69 40.4 0.0866 1.041 128.2 48.1 17.0
2005 12 08 07 40.17 +70 19.5 0.0771 1.033 126.9 49.7 16.8
2005 12 09 08 07.05 +70 55.7 0.0676 1.025 125.1 51.8 16.5
2005 12 10 08 44.21 +71 18.9 0.0583 1.018 122.8 54.5 16.3
2005 12 11 09 35.54 +71 04.4 0.0492 1.010 119.4 58.1 16.0
2005 12 12 10 42.56 +69 16.7 0.0405 1.002 114.5 63.4 15.7
2005 12 13 11 58.32 +64 09.8 0.0325 0.994 106.8 71.5 15.4
2005 12 14 13 08.38 +53 02.6 0.0257 0.987 94.3 84.2 15.4
2005 12 15 14 03.39 +33 26.9 0.0214 0.979 75.0 103.8 15.8
2005 12 16 14 43.48 +08 24.4 0.0213 0.971 52.4 126.6 17.4
Timothy B. Spahr (C) Copyright 2005 MPC M.P.E.C. 2005-W36
SNR Calculation
Target Name: 2005 WC1
HMag: 20.5
Diameter: 0.25 km (a standard guess assuming 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
2005 12 9 128 71 0.060 631 41 2 1:42-20:36 0 0 0 -
2005 12 10 140 71 0.050 700 80 4 2:30-21:23 0 0 0 -
2005 12 11 157 70 0.041 700 167 7 4:00-22:00 0 0 0 -
2005 12 12 178 65 0.032 700 389 16 6:12-22:23 0 0 0 -
2005 12 13 197 54 0.025 700 947 39 8:30-22:23 0 0 0 -
2005 12 14 212 34 0.021 700 1839 76 10:35-22:11 124 14800 1530 12:11-14:00
2005 12 15 222 7 0.021 616 1705 75 12:24-21:41 142 17200 1560 12:35-14:48
2005 12 16 229 -15 0.025 412 639 35 14:05-20:53 0 0 0 -
2005 12 17 235 -28 0.033 243 174 12 15:41-19:48 0 0 0 -
2005 12 18 239 -36 0.041 112 45 4 - 0 0 0 -
2005 12 19 242 -42 0.050 0 0 0 - 0 0 0 -
Arecibo SNRs have been adjusted to reflect current transmitter power of about 500 kW.
However, 2005 WC1 moves so fast that it goes through Arecibo's declination window in only
one day, contrary to what is shown for 00:00:00 UTC on each day above.
Goldstone Track Assignments
2005 WC1 Goldstone track
UT UT PST Duration
DOY Date TX Window TX Window AST TX Window (hh:mm)
--- ---- --------- ------------- ------------- -------
349 Dec 15 1315-1530 0515-0730 0915-1130 2:15
Arecibo track
348 Dec 14 1201-1451 0401-0651 0801-1051 2:50
Uncertainties
From Horizons: 2005 November 28, solution #5
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S-sig DOP_X-sig RT_delay-sig
2005-Dec-10 00:00 *m 139.96066 71.34055 0.050452858840 838.423770 9030.72 32300.11 2.523742
2005-Dec-11 00:00 *m 156.90637 70.02419 0.041320428902 1441.09795 8570.81 30655.15 2.193273
2005-Dec-12 00:00 *m 177.04709 65.47657 0.032823254516 2608.64312 7703.29 27552.29 1.861384
2005-Dec-13 00:00 *m 196.17659 54.66082 0.025601044804 4856.56424 5921.81 21180.47 1.509142
2005-Dec-14 00:00 *m 211.10588 34.48179 0.021016811103 8098.69785 2393.90 8562.23 1.106349
2005-Dec-15 00:00 *m 221.74116 7.99462 0.020896126127 9142.83005 2446.89 8751.76 0.755140
2005-Dec-16 00:00 * 229.23752 -13.92680 0.025315024229 6908.49306 6036.49 21590.66 0.700693
2005-Dec-17 00:00 * 234.64663 -27.69824 0.032482913662 4626.75432 7846.19 28063.41 0.849101
2005-Dec-18 00:00 * 238.67710 -36.02539 0.040994644174 3186.40442 8718.51 31183.42 1.074478
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Horizons: 2005 December 6, solution #9, #obs: 50 (14 days)
2005-Dec-10 00:00 *m 140.26964 71.33398 0.050054603337 69.4748773 2990.92 10697.61 0.695027
2005-Dec-11 00:00 *m 157.36270 69.96707 0.040943560459 135.274473 2837.44 10148.66 0.586964
2005-Dec-12 00:00 *m 177.59518 65.29141 0.032478736279 271.079804 2545.77 9105.45 0.483577
2005-Dec-13 00:00 *m 196.69200 54.21812 0.025316147484 548.340417 1943.33 6950.69 0.387361
2005-Dec-14 00:00 *m 211.52228 33.68478 0.020849082271 973.312217 752.09 2689.98 0.303795
2005-Dec-15 00:00 *m 222.06257 7.09839 0.020895157107 1147.19824 856.82 3064.58 0.253665
2005-Dec-16 00:00 * 229.48753 -14.58332 0.025441967163 903.572449 2027.57 7251.99 0.264268
2005-Dec-17 00:00 * 234.84597 -28.12157 0.032673737988 632.368410 2613.90 9349.12 0.324450
2005-Dec-18 00:00 * 238.84036 -36.30543 0.041212802032 454.208263 2897.27 10362.65 0.410952
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Horizons: 2005 December 7, solution #10, #obs: 60 (15 days)
2005-Dec-10 00:00 *m 140.27494 71.33360 0.049996107867 23.1944398 1715.76 6136.73 0.377651
2005-Dec-11 00:00 *m 157.37150 69.96557 0.040894037261 47.8071916 1628.09 5823.19 0.316185
2005-Dec-12 00:00 *m 177.60680 65.28677 0.032437829741 99.9616706 1461.25 5226.44 0.258061
2005-Dec-13 00:00 *m 196.70385 54.20647 0.025283338080 208.956998 1116.20 3992.30 0.205733
2005-Dec-14 00:00 *m 211.53255 33.66234 0.020823481706 380.693843 433.28 1549.72 0.164331
2005-Dec-15 00:00 *m 222.07101 7.07142 0.020874181054 458.292856 489.48 1750.71 0.145595
2005-Dec-16 00:00 * 229.49448 -14.60448 0.025420555002 367.512395 1161.11 4152.94 0.159842
2005-Dec-17 00:00 * 234.85180 -28.13621 0.032647604573 261.286644 1497.71 5356.86 0.198905
2005-Dec-18 00:00 * 238.84537 -36.31580 0.041179642932 190.301869 1660.57 5939.36 0.250937
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Jon Giorgini: 2005 December 12:
With 112 optical observations (2005-Nov-21 to 2005-Dec-11),
2005 WC1 solution #14 was computed and found to have 3-sigma
S & X-band uncertainties as shown below.
Date__(UT)__HR:MN POS_3sigma DOP_S-sig DOP_X-sig RT_delay-sig
2005-Dec-13 00:00 6.55801780 345.51 1235.79 0.054064
2005-Dec-14 00:00 15.4333261 136.04 486.58 0.044595
2005-Dec-15 00:00 22.4163516 147.60 527.93 0.044058
2005-Dec-16 00:00 20.8043306 354.85 1269.18 0.052771
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
From Jon Giorgini: 2005 December 14:
With the 3 Dopplers and 1 delay from Arecibo, combined with 118 optical
observations spanning 2005-Nov-21 to 2005-Dec-12, 2005 WC1 solution #22
was computed.
3-sigma X-band (and S-band) uncertainties are shown below:
Date__(UT)__HR:MN POS_3sigma DOP_S-sig DOP_X-sig RT_delay-sig
2005-Dec-13 00:00 1.13341184 2.12 7.59 0.000094
2005-Dec-14 00:00 1.53456909 1.32 4.72 0.000026
2005-Dec-15 00:00 2.02094945 0.39 1.38 0.000021
2005-Dec-16 00:00 2.14474682 1.12 4.02 0.000105
Setups
CW Setup
Arecibo observations on December 14 revealed an S-band bandwidth of about 2.5 Hz and a visible range
extent of about 150 m, so the X-band bandwidth could be close to 9 Hz and the diameter close
to 300 meters. Given that the ephemeris uncertainties are now small, we'll start with the
following cw setup for about ten minutes, and then we'll go to 1/8 usec imaging.
Note: the round-trip time is only about 23 seconds, so we may not get two complete hops
per run.
TX polarization RCP
RCV polarization LCP
Frequencies: 2
Dwell: 10 seconds
Bandwidth: 4000 Hz
Sampling interval: 2500 x 0.1 usec
VME FFT for PSD files: 8192 for 0.488-Hz resolution
Possible ranging setups:
---------------------------------------------------------------------------
127 x 64 10-usec single sample
baud 10 usec
code 127
gates 127
FFT 64
CLT 11
ncoh 2
bandwidth 394 Hz
resolution 6.15 Hz
TXOFF +60 Hz -> echo will be centered at +9.75 bins or in bin 32+10 = 42
incoh sums 64 => 10.4 sec/record
---------------------------------------------------------------------------
127 x 64 11-usec single sample, 5.6-Hz resolution.
baud 11 usec
code 127
gates 127
PRP 1397
FFT 64
CLT 11
ncoh 2
bandwidth 357.9 Hz
resolution 5.59 Hz
TXOFF TBD
-------------------------------------------------------------------------
127 x 64 11-usec single sample, 11.2-Hz resolution
baud 11 usec
code 127
gates 127
PRP 1397
FFT 64
CLT 11
ncoh 1
bandwidth 715.8 Hz
resolution 11.2 Hz
TXOFF +60 -> echo would be centered at +5 bins w/perfect ephemeris
-------------------------------------------------------------------------
127 x 64 7-usec single sample
------------------------------
baud 7 usec
code 127
gates 127
PRP 889
FFT 64
CLT 11
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 13 & 14, about evenly divided
ncoh 15
bandwidth 525 Hz
resolution 8.2 Hz
TXOFF +50 -> echo would be centered at +6.1 bins w/perfect ephemeris
-------------------------------------------------------------------------------
0.125-usec ranging setup used in first UY4 track (DOY 213, Aug. 1)
------------------
setup JX1XS001 revised
baud 0.125 usec
code 127
gates 127
FFT 64
ncoh 984
bandwidth 64.016384 Hz
resolution 1.000256 Hz
TXOFF We used 10 Hz, placing COM in cell 32+10=42
Henceforth use 15 Hz, to put COM in 32+15=47
incoh sums 4 looks=> 8 sec/record => expect records per run ~ RTT/8
PFS CLT gate 21
_____________________________________________________________________
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/2005WC1/raw/
2005 WC1 POINTING:
OSOD and predicts are at Goldstone on stealth:
/export/data2/osod/ops/2005wc1/PRDX.OUT.s22
/PUNCH.OUT.s22
/EPH.OUT.s22
and have been copied to:
/export/data0/rosema/2005WC1/support/
POINTING
TX Offsets
Date (UTC) DOY hhmmss RA Dec Macro LHA Dec RTT OSOD
2005 12 15 349 130000 226.5569 -5.7222 A 22.8 22
2005 12 15 349 140000 226.8447 -6.6088 A 23.0
2005 12 15 349 150000 227.1241 -7.4795 A -0.0018 -0.0056 23.3
2005 12 15 349 160000 227.3964 -8.3342 A 23.4
2005 12 15 349 170000 227.6630 -9.1725 A 23.7
PRDX.OUT.s22
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
2005 DEC 15 13:10 22.8767695535 -457631.682 298.2930 -5.8711 226.605 18.960
2005 DEC 15 13:20 22.9089476356 -460520.116 300.7515 -6.0195 226.654 20.706
2005 DEC 15 13:30 22.9413289889 -463431.435 303.2102 -6.1674 226.702 22.424
2005 DEC 15 13:40 22.9739151788 -466364.720 305.6693 -6.3150 226.750 24.111
2005 DEC 15 13:50 23.0067077111 -469318.993 308.1285 -6.4621 226.797 25.765
2005 DEC 15 14:00 23.0397080282 -472293.217 310.5880 -6.6087 226.845 27.383
2005 DEC 15 14:10 23.0729174835 -475286.296 313.0477 -6.7550 226.892 28.959
2005 DEC 15 14:20 23.1063373659 -478297.084 315.5077 -6.9008 226.939 30.492
2005 DEC 15 14:30 23.1399688679 -481324.378 317.9678 -7.0461 226.985 31.977
2005 DEC 15 14:40 23.1738131028 -484366.927 320.4282 -7.1910 227.032 33.410
2005 DEC 15 14:50 23.2078710950 -487423.433 322.8888 -7.3355 227.078 34.785
2005 DEC 15 15:00 23.2421437830 -490492.552 325.3496 -7.4795 227.124 36.099
2005 DEC 15 15:10 23.2766320028 -493572.897 327.8106 -7.6231 227.170 37.346
2005 DEC 15 15:20 23.3113364769 -496663.042 330.2718 -7.7662 227.216 38.521
2005 DEC 15 15:30 23.3462578560 -499761.524 332.7332 -7.9089 227.261 39.618
GOLDSTONE MASTERLOG
==============================================================================
RCV
file setup runs start -stop osod OFFSET TX Poln
------------------------------------------------------------------------------
December 15 (DOY 349)
CW 2 hops, 4 kHz, 10s dwell 13 132514-133510 22 none RCP VME & PFS
1/8 us 127 code ncoh=1970 91 141741-153026 24 +7 Hz RCP VME & PFS
==============================================================================
RADAR ASTROMETRY
2005 12 15 13:30:00 P -463428.4D0 1.0 8560.D6 -14 -14 Benner, L.A.M.
Correction of +3 Hz to soln 22 from 13 cw runs with 0.5 Hz resn.
Bandwidth is about 8 Hz.
==============================================================================
PRELIMINARY IMAGING RESULTS
Resolution: 0.125 usec (19 meters) x 0.25 Hz
14:17 - 14:34 UTC
14:34 - 14:47 UTC
14:47 - 15:02 UTC
15:02 - 15:15 UTC
15:15 - 15:30 UTC
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/2005WC1/goldstone/html/2005WC1_planning.html
Asteroid Radar Astronomy