6R10DB9 Planning


Background


6R10DB9 was discovered by the Catalina Sky Survey (University of Arizona) in September, 2006.  
It is only a few meters in diameter and it is currently orbiting Earth as a temporary satellite.
It is making its fourth and final revolution about Earth and will return to solar orbit later
in the summer.  This is a type of object that has been predicted theoretically but, until
now, never observed.  

6R10DB9 is small enough that solar radiation pressure is perturbing its motion perceptibly.  
According to Paul Chodas in JPL's Solar System Dynamics Group, the magnitude of the perturbations 
is consistent with expectations for a rocky object but not with old flight hardware, so this 
is probably a natural object.  

Although its origin is unknown, one plausible explanation is that it could be material
ejected off the Moon by an impact.  Consequently, any observations that can constrain its
origin are very important.

6R10DB9 will approach within 0.7 lunar distances (!) on June 14 when it will be a strong 
radar target.  This is the closest and smallest asteroid that we have ever attempted to observe.  

Goldstone observations are scheduled on June 12, 14, and 17.
Arecibo is offline for maintenance and cannot observe it.

Due to the asteroid's very short round-trip time, all the observations will be bistatic, using
DSS-13 as a receiver on June 12 and 14 and (due to a scheduling conflict) DSS-25 on June 17.

Photometry obtained in March by Tomasz Kwiatkowski et al. using the 10-m South African
Large Telescope revealed a rotation period of 2.75 minutes and a large lightcurve amplitude
of 1.2 mag.  Consequently, this object may be quite elongated.

6R10DB9 will move about 120 degrees during the interval spanned by our observations,
so we may see bandwidth changes from night to night.

Physical Characteristics
 orbit type              Apollo
 absolute magnitude (H)  29.5
 diameter                 roughly 4 meters
 rotation period          2.75 minutes (Tomasz Kwiatkowski et al.)
 pole direction           unknown
 lightcurve amplitude     1.2 mag at 74 deg solar phase angle  (Tomasz Kwiatkowski et al.)
 spectral class           unknown

Last updated: 2007 June 14

Discovery

THIS OBJECT DOES NOT HAVE A FORMAL DISCOVERY ANNOUNCEMENT.

Instead, see Bill Gray's psuedo MPEC website at:
http://home.gwi.net/~pluto/mpecs/6r1.htm

Peter Birtwhistle at Great Shefford Observatory (United Kingdom) also has a website
that describes this object:  
http://www.birtwhistle.org/Gallery6R10DB9.htm

In its July 2007 issue, Sky and Telescope magazine ran a short article about 6R10DB9.  
It's available at:
http://www.skyandtelescope.com/news/home/7067527.html


SNR Calculation

Target Name:    6R10DB9
HMag:           29.5
Diameter:       4 meters     (an educated guess assuming H = 29.5 and an S-class optical albedo)
Period:         2.75 minutes (= 0.046 hours)

The SNRs for Goldstone below assume reception at DSS-13.

                           ------------GOLDSTONE----------  -------------ARECIBO-----------
                                            Max                              Max
                                    Date    Run    UTC               Date    Run    UTC
    Date   RA  Decl Delta  Runs     SNR     SNR   Window    Runs     SNR     SNR   Window
2007  6  8 124 -29  0.0037  700      43       2 21:11-24:53    0       0       0      -
2007  6  9 124 -22  0.0033  700      72       3 20:06-25:48    0       0       0      -
2007  6 10 124 -12  0.0029  700     120       5 19:18-26:30    0       0       0      -
2007  6 11 124   1  0.0025  700     200       9 18:30-27:11  237   12200     890 18:48-20:06
2007  6 12 124  18  0.0022  700     330      14 17:36-27:53  464   35700    1700 18:06-20:48
2007  6 13 124  40  0.0019  700     510      22 16:36-28:53    0       0       0      -
2007  6 14 124  67  0.0018  700     520      24 14:11-31:06    0       0       0      -
2007  6 15 304  85  0.0019  700     540      21  0:00-24:00    0       0       0      -
2007  6 16 304  60  0.0021  700     350      16  3:00-18:00    0       0       0      -
2007  6 17 304  42  0.0024  700     705      10  4:17-16:41    0       0       0      -
2007  6 18 305  27  0.0028  700     230       6  4:54-15:54  411   14600     770  5:47- 8:18
2007  6 19 305  16  0.0032  700      95       4  5:17-15:24  424    9600     490  5:42- 8:18
2007  6 20 305   8  0.0036  700      64       3  5:35-14:54  348    5700     330  5:47- 8:05
2007  6 21 305   1  0.0039  700      45       2  5:54-14:30  204    2400     190  6:17- 7:30

Dates of scheduled tracks are highlited in bold.

Arecibo is offline for maintenance and cannot observe this object.  


Track Assignments


6R10DB9 Goldstone Schedule
P = 2.75 minutes (0.046 hours)

      UT        UT       PDT                 Duration  Round-trip Lunar
DOY  Date    TX Window   TX Window           hh:mm     time (sec) Distances  Rotations       
---  ----    ---------   ---------           -------   ---------  ---------  ---------
163  Jun 12  0135-0355   1835-2055 Jun 11     2:20       2.2       0.86       51
165  Jun 14  0430-0630   2130-2330 Jun 13     2:00       1.8       0.70       44
168  Jun 17  0545-0840   2245-0140 Jun 16-17  2:55       2.5       0.97       64



Uncertainties

From Jon Giorgini and Paul Chodas, 2007 June 4:
With 112 measurements spanning 2006-Sep-14 to 2007-Mar-20,
6R10DB9 solution #28 (from Paul) has 3-sigma formal X-band
uncertainties as shown below:

 Date__(UT)__HR:MN   POS_3sigma  DOP_X-sig  RT_delay-sig
 2007-Jun-12 00:00   6.54154266       1.40      0.000021
 2007-Jun-13 00:00   7.53689976       1.71      0.000015
 2007-Jun-14 00:00   7.69009903       1.85      0.000017
 2007-Jun-15 00:00   6.59180067       1.66      0.000024
 2007-Jun-16 00:00   5.08095359       1.30      0.000029
 2007-Jun-17 00:00   3.94470079       0.96      0.000030
 2007-Jun-18 00:00   3.24965488       0.71      0.000030

These could be optimistic depending on the actual solar
pressure systematics, but the predicts themselves include a 
nominal solar pressure force model.

Setups

Due to the very short round-trip times, all the Goldstone observations will be bistatic,
using DSS-13 as a receiver on June 12 and 14 and DSS-25 on June 17.  The SNRs probably
won't be strong enough for testing the chirp/digital receiver system.

Plans for the June 17 track:

WE WILL START WITH SOLUTION 32

We are expecting a bandwidth of roughly 10 Hz, so we're going to start with a CW setup that 
will enable us to see a detection quickly and also resolve the echoes.   As noted above, this
object appears to be quite elongated, so its bandwidth may vary substantially.

We do not plan to do any ranging.

Bistatic CW setup for the June 17 track 
---------------------------------------
TX polarization           RCP
RCV polarization          LCP & RCP
Frequency hops:            2
Dwell:                    30 seconds
Bandwidth:              2000 Hz  
Sampling interval:      5000 x 0.1 usec 
VME FFT for PSD files:  8192 for 0.24-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 (left over from the 1992 UY4 observations in August, 2005)
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/6R10DB9/raw/

6R10DB9 POINTING:

   OSOD and predicts are at Goldstone on stealth:

June 12:
   /export/data3/osod/ops/6R10DB9/ PRDX.OUT.Jun12.14c-13v.s28
                                 /PUNCH.OUT.Jun12.14c-13v.s28

June 14:
   /export/data3/osod/ops/6R10DB9/ PRDX.OUT.Jun14.14c-13v.s30
                                 /PUNCH.OUT.Jun14.14c-13v.s30

June 17:
   /export/data3/osod/ops/6R10DB9/ PRDX.OUT.Jun14.14c-25v.s32
                                 /PUNCH.OUT.Jun14.14c-25v.s32

                                 /EPH.OUT.s32

and have been copied to:
   /export/data0/rosema/6R10DB9/support/


POINTING  
                                                  TX Offsets    
Date (UTC)   DOY  hhmmss    RA       Dec   Macro  LHA      Dec   RTT (s) OSOD
2007 06 12   163  000000 124.2257 17.9062   A                      2.20   28 
2007 06 12   163  010000 124.0057 18.6861   A    0.0001   0.0005   2.19   
2007 06 12   163  020000 123.8191 19.4549   AB                     2.18
2007 06 12   163  030000 123.6800 20.2144    B   0.0001   0.0005   2.18
2007 06 12   163  040000 123.5995 20.9679    B                     2.17

2007 06 14   165  030000 122.7280 70.2587   A                      1.82   28
2007 06 14   165  040000 122.4009 71.1839   A    0.0001   0.0005   1.82
2007 06 14   165  050000 122.2825 72.0974   AB                     1.82
2007 06 14   165  060000 122.4038 73.0181    B  -0.0001   0.0005   1.83
2007 06 14   165  070000 122.7859 73.9637    B                     1.83

2007 06 17   168  050000 305.1839 38.8496   A                      2.46   28
2007 06 17   168  060000 305.1040 38.3266   A    0.0000  -0.0004   2.47
2007 06 17   168  070000 304.9617 37.7935   AB                     2.48
2007 06 17   168  080000 304.7687 37.2432    B   0.0001  -0.0004   2.49
2007 06 17   168  090000 304.5396 36.6703    B                     2.50


PRDX.OUT.Jun12.14c-13v.s28 TRANSMITTER: STATION #14, RECEIVER: STATION #13 RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL 2007 JUN 12 01:30 2.1869575415 16742.699 41.8061 19.0747 123.905 49.811 2007 JUN 12 01:40 2.1858085263 16047.408 44.3436 19.2026 123.874 47.848 2007 JUN 12 01:50 2.1847072056 15381.966 46.8798 19.3303 123.845 45.871 2007 JUN 12 02:00 2.1836514520 14747.518 49.4149 19.4577 123.816 43.884 2007 JUN 12 02:10 2.1826390497 14145.141 51.9485 19.5848 123.790 41.889 2007 JUN 12 02:20 2.1816677153 13575.839 54.4808 19.7116 123.764 39.890 2007 JUN 12 02:30 2.1807350974 13040.541 57.0116 19.8383 123.740 37.888 2007 JUN 12 02:40 2.1798387847 12540.103 59.5410 19.9647 123.718 35.885 2007 JUN 12 02:50 2.1789763064 12075.303 62.0687 20.0909 123.697 33.883 2007 JUN 12 03:00 2.1781451343 11646.842 64.5949 20.2169 123.677 31.885 2007 JUN 12 03:10 2.1773427072 11255.341 67.1195 20.3427 123.660 29.891 2007 JUN 12 03:20 2.1765664068 10901.343 69.6423 20.4684 123.644 27.903 2007 JUN 12 03:30 2.1758135957 10585.312 72.1635 20.5940 123.629 25.923 2007 JUN 12 03:40 2.1750815910 10307.629 74.6829 20.7195 123.617 23.951 2007 JUN 12 03:50 2.1743676964 10068.597 77.2005 20.8448 123.606 21.990 2007 JUN 12 04:00 2.1736691972 9868.439 79.7164 20.9701 123.597 20.040 PRDX.OUT.Jun14.14c-13v.s30 TRANSMITTER: STATION #14, RECEIVER: STATION #13 2007 JUN 14 04:30 1.8234534245 -5749.478 90.4995 71.6406 122.306 33.058 2007 JUN 14 04:40 1.8238563386 -5744.807 93.0229 71.7926 122.289 32.327 2007 JUN 14 04:50 1.8242584689 -5727.204 95.5399 71.9446 122.279 31.618 2007 JUN 14 05:00 1.8246589287 -5697.233 98.0503 72.0968 122.276 30.931 2007 JUN 14 05:10 1.8250568715 -5655.481 100.5540 72.2491 122.279 30.267 2007 JUN 14 05:20 1.8254514927 -5602.557 103.0509 72.4018 122.289 29.626 2007 JUN 14 05:30 1.8258420311 -5539.088 105.5409 72.5548 122.305 29.010 2007 JUN 14 05:40 1.8262277701 -5465.720 108.0238 72.7083 122.329 28.419 2007 JUN 14 05:50 1.8266080391 -5383.115 110.4996 72.8623 122.360 27.853 2007 JUN 14 06:00 1.8269822147 -5291.948 112.9683 73.0170 122.399 27.313 2007 JUN 14 06:10 1.8273497180 -5192.906 115.4296 73.1723 122.444 26.800 2007 JUN 14 06:20 1.8277100227 -5086.687 117.8836 73.3285 122.497 26.313 2007 JUN 14 06:30 1.8280626523 -4973.998 120.3302 73.4855 122.557 25.853 PRDX.OUT.Jun17.14c-25v.s32 TRANSMITTER: STATION #14, RECEIVER: STATION #25 2007 JUN 17 05:40 2.4670841863 -18536.770 288.0906 38.5028 305.139 33.939 2007 JUN 17 05:50 2.4683914213 -18768.348 290.6136 38.4154 305.123 35.762 2007 JUN 17 06:00 2.4697160105 -19031.995 293.1383 38.3278 305.105 37.601 2007 JUN 17 06:10 2.4710601966 -19327.374 295.6648 38.2399 305.085 39.457 2007 JUN 17 06:20 2.4724261879 -19654.083 298.1930 38.1516 305.064 41.328 2007 JUN 17 06:30 2.4738161645 -20011.651 300.7229 38.0630 305.041 43.214 2007 JUN 17 06:40 2.4752322689 -20399.543 303.2544 37.9741 305.016 45.114 2007 JUN 17 06:50 2.4766766082 -20817.159 305.7873 37.8846 304.990 47.027 2007 JUN 17 07:00 2.4781512428 -21263.834 308.3218 37.7948 304.962 48.953 2007 JUN 17 07:10 2.4796581825 -21738.839 310.8577 37.7044 304.933 50.892 2007 JUN 17 07:20 2.4811993877 -22241.383 313.3950 37.6136 304.903 52.841 2007 JUN 17 07:30 2.4827767555 -22770.616 315.9335 37.5222 304.871 54.802 2007 JUN 17 07:40 2.4843921307 -23325.626 318.4733 37.4302 304.838 56.773 2007 JUN 17 07:50 2.4860472828 -23905.444 321.0142 37.3376 304.804 58.754 2007 JUN 17 08:00 2.4877439170 -24509.046 323.5562 37.2445 304.769 60.745 2007 JUN 17 08:10 2.4894836611 -25135.352 326.0992 37.1507 304.733 62.744 2007 JUN 17 08:20 2.4912680690 -25783.232 328.6432 37.0562 304.696 64.751 2007 JUN 17 08:30 2.4930986099 -26451.504 331.1880 36.9611 304.658 66.767 2007 JUN 17 08:40 2.4949766725 -27138.940 333.7335 36.8653 304.619 68.789 2007 JUN 17 08:50 2.4969035516 -27844.267 336.2798 36.7689 304.580 70.819 2007 JUN 17 09:00 2.4988804595 -28566.168 338.8266 36.6717 304.540 72.854

6R10DB9 GOLDSTONE MASTERLOG

============================================================================== RCV TX setup runs start -stop osod OFFSET Poln Notes ------------------------------------------------------------------------------ JUNE 12 PSD2007163.107.6R10DB9, PSD2007163.109.6R10DB9, VOLT2007163.108.6R10DB9 (file 109 has only two hops) CW 4 kHz, 2 hops, 30 s dwell 4096 PSD FFT -- 014401-015401 28 None RCP Echo PSD2007163.110.6R10DB9, VOLT2007163.111.6R10DB9 CW 4 kHz, 2 hops, 30 s dwell 8192 PSD FFT -- 015600-022437 28 None RCP Echo PSD2007163.112.6R10DB9, VOLT2007163.113.6R10DB9 (hops 1-11) CW 4 kHz, 2 hops, 30 s dwell 8192 PST FFT -- 022632-023134 30 None RCP No Echo PSD2007163.112.6R10DB9, VOLT2007163.113.6R10DB9 (same files as last setup: hops 12-63) CW 4 kHz, 2 hops, 30 s dwell 8192 PST FFT -- 023431-030007 28 None RCP Echo PSD2007163.114.6R10DB9, VOLT2007163.115.6R10DB9 CW 4 kHz, 2 hops, 30 s dwell 8192 PST FFT -- 030130-033053 28 None LCP Echo PSD2007163.116.6R10DB9, VOLT2007163.117.6R10DB9 CW 4 kHz, 2 hops, 30 s dwell 8192 PST FFT -- 033132-035519 28 None RCP Echo ------------------------------------------------------------------------------ JUNE 14 ------------------------------------------------------------------------------ JUNE 17 ============================================================================== RADAR ASTROMETRY 2007 06 12 01:50:00 P 15380.D0 1.0 8560.D6 -14 -13 Benner, L.A.M. Correction of -2 Hz to solution 28 from CW with 0.5 Hz resolution. 2007 06 14 04:40:00 P -5745.8D0 1.0 8560.D6 -14 -13 Benner, L.A.M. Corr'n of -1 Hz to soln 30 from wtd sum of 10 minutes of CW with 0.24 Hz resolution. Bandwidth is 4 Hz. ==============================================================================
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 Pasadena, CA 91109-8099 | Plan: To live long and prosper http://echo.jpl.nasa.gov/asteroids/6R10DB9/html/6R10DB9_planning.html

Asteroid Radar Astronomy