Goldstone Radar Observations Planning: (231937) 2001 FO32
2001 FO32
(231937) 2001 FO32 was discovered on March 23, 2001 by LINEAR, and on March 21, it will approach
within 0.0135 au (5.3 lunar distances). During this encounter, the asteroid will brighten to about
12th magnitude when it should be visible for experienced observers with small telescopes.
NEOWISE spacecraft data (Ned Wright, pers. comm.) indicate that 2001 FO32 is about 0.6 km in diameter.
Given the asteroid's absolute magnitude of 17.7, the diameter corresponds to an optical albedo of about
0.5, which is exceptionally bright.
Lightcurves obtained by Petr Pravec (pers. comm.) reveal that 2001 FO32 is a slow, non-principal axis
rotator with a fundamental period of 40 hours and a second period of roughly 53 hours. The lightcurve
amplitude is 0.9 magnitudes and probably indicates that the shape is very elongated.
The asteroid will approach from the south and enter Goldstone's declination window on March 21
shortly before the time of closest approach. The 70 m DSS-14 antenna at Goldstone is offline
for maintenance and will not be able to observe 2001 FO32 with radar, but we have scheduled
time on the 34 m DSS-13 antenna and the 100 m Green Bank Telescope on March 22, when the radar
signal-to-noise ratios should still be strong enough for delay-Doppler imaging.
2001 FO32 has an unusually high orbital eccentricity and a perihelion distance of only 0.3 au,
which is inside the average distance of Mercury from the Sun. The aphelion is at 3.1 au and is
deep within the outer main asteroid belt. The orbit also has a steep 39 degree inclination.
The asteroid will move rapidly across the sky during the encounter and will become a daytime object
on March 22.
2001 FO32 makes relatively frequent close approaches within 0.1 au of Earth, Venus, and Mercury.
The 2021 encounter is the closest with Earth for at least the next few centuries.
Goldstone DSS-13 > Green Bank Bistatic Radar Images of Asteroid (231937) 2001 FO32
Delay-Doppler radar images of 2001 FO32 obtained on March 22 by transmitting with the 34 meter
DSS-13 antenna at Goldstone and receiving with the 100 meter Green Bank Telescope
in West Virginia. Resolution is 37.5 m x 0.1 Hz. In each panel, range increases
down and Doppler frequency increases to the left, so the illumination comes from the
top and rotation is clockwise. In the collage, time increases from the top left
panel to the lower left panel, etc., so the last frame in the sequence is at the lower
right. Each image is an integration spanning five minutes with a ten minute gap
between frames. The sequence of images spans about 110 minutes.
The images reveal that 2001 FO32 is elongated and shaped somewhat like a peanut with a
long axis of about 1.2 km. The rotation evident in the images is consistent with the
40 h principal rotation period reported by Petr Pravec et al. The long axis is larger
than the diameter estimated from NEOWISE data, so it's possible (and perhaps probable)
that NEOWISE observed the asteroid when it was closer to an end-on orientation than
the broadside orientation seen in the radar images.
Orbital and Physical Characteristics
Name 2001 FO32
Asteroid number 231937
Discoverer LINEAR
Discovery date 2001 March 23
orbit type Apollo
Close approach distance 0.0135 au (5.25 lunar distances)
Close approach date 2021 Mar 21
semimajor axis 1.701 au
eccentricity 0.826
inclination 38.9 deg
Orbital period 2.219 years
perihelion distance 0.296 au
aphelion distance 3.106 au
MOID 0.049 au
absolute magnitude (H) 17.7
diameter 0.56 km (Ned Wright, pers. comm., NEOWISE data)
optical albedo 0.48 (Ned Wright, pers. comm., NEOWISE data)
rotation period 39.89 +-0.06 h (P. Pravec, pers. comm.)
lightcurve amplitude 0.9 mag (P. Pravec, pers. comm.)
pole direction NPA
spectral class unknown
PHA? Yes
Last update: 2021 April 9
Discovery M.P.E.C.
2001 FO32
https://www.minorplanetcenter.net/mpec/K01/K01F32.html
SNR Calculations
Goldstone SNRs
2001 FO32: D = 0.6 km, P = 39.89 h, OC albedo = 0.1
20 deg horizons Monostatic DSS-14 DSS13>GBT
DOY start date window RA, dec dist runs SNR/day SNR/run SNR/RTT
80 2021 Mar 21 13:25-19:56 302, -23 0.013 733 91000 3600 290 Scheduled at Canberra and ATCA
81-82 2021 Mar 22-23 13:43-00:11 346, +14 0.026 695 11000 430 34 Scheduled at DSS-13 and GBT
82-83 2021 Mar 23-24 14:06-01:01 357, +22 0.045 434 1200 64 5
83-84 2021 Mar 24-25 14:14-01:21 2, +26 0.064 310 290 18 1
84-85 2021 Mar 25-26 14:18-01:30 5, +27 0.084 240 100 7
85-86 2021 Mar 26-27 14:18-01:35 6, +28 0.104 195 43 3
86-87 2021 Mar 27-28 14:18-01:36 8, +29 0.124 165 22 2
With a 40 h rotation period, imaging integrations spanning one hour
will show only 9 degrees of rotation.
Track Assignments
DOY BOA BOT EOT EOA
81 1330 1705 1735 DSSR AST 2001 FO32
Goldstone tracks:
UT UT PDT Duration Round-trip
DOY Date TX Window TX Window hh:mm time (sec)
81 Mar 22 1330-1705 0630-1005 Mar 11 3:35 23
The DSS-13 BOT time occurs at an elevation of about 18 deg, so we
may need to transmit less than 80 kW initially.
Elevations (degrees) early in the track:
Time DSS-13 GBT
12:45 8.6 37.4
13:00 11.6 40.1
13:15 14.6 42.8
13:30 17.6 45.4
13:45 20.6 47.9
GBT schedule: 1300-1715 UT (0600-1015 PDT)
Uncertainties
2001 FO32
JPL/Horizons solution 60, # obs: 202 (2001-2021)
2021 Mar 19
Note: C-band Doppler uncertainties are about (0.84)x X-band uncertainties.
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2021-Mar-18 00:00 *m 205.31643 -36.47676 0.07418195411994 1.798 0.95 3.47 0.000790
2021-Mar-19 00:00 *m 209.77897 -37.85444 0.05474554860309 2.576 1.63 5.91 0.000775
2021-Mar-20 00:00 *m 219.50086 -40.11698 0.03581916257311 4.331 4.04 14.69 0.000730
2021-Mar-21 00:00 *m 250.38162 -41.49152 0.01895646322420 9.877 17.73 64.44 0.000555
2021-Mar-22 00:00 *m 321.20329 -7.78483 0.01501778725967 10.866 23.88 86.78 0.000735
2021-Mar-23 00:00 *m 349.33447 16.61405 0.02969681735565 4.034 4.11 14.92 0.000931
2021-Mar-24 00:00 *m 358.43935 23.19717 0.04826952879827 2.519 1.63 5.93 0.000947
2021-Mar-25 00:00 *m 2.68706 25.89305 0.06761997738471 1.876 0.97 3.54 0.000955
Hourly intervals on March 21:
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2021-Mar-21 12:00 286.98095 -31.72613 0.01387580748131 14.414 34.75 126.31 0.000457
2021-Mar-21 13:00 N 290.33768 -30.05003 0.01369568759767 14.534 35.46 128.87 0.000468
2021-Mar-21 14:00 * 293.64683 -28.24624 0.01356472453031 14.569 35.85 130.28 0.000484
2021-Mar-21 15:00 * 296.88868 -26.33104 0.01348448177571 14.513 35.89 130.43 0.000503
2021-Mar-21 16:00 * 300.04615 -24.32460 0.01345598924624 14.364 35.57 129.28 0.000526
Hourly intervals during the track on March 22:
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2021-Mar-22 13:00 N 340.98093 9.60609 0.02197533605794 5.797 8.16 29.67 0.000897
2021-Mar-22 14:00 * 341.95875 10.45422 0.02262695207852 5.574 7.57 27.53 0.000902
2021-Mar-22 15:00 * 342.88071 11.25134 0.02329011306759 5.367 7.04 25.60 0.000906
2021-Mar-22 16:00 * 343.75117 12.00070 0.02396436799582 5.175 6.56 23.86 0.000910
2021-Mar-22 17:00 * 344.57443 12.70537 0.02464928194251 4.996 6.13 22.29 0.000914
2021-Mar-22 18:00 * 345.35463 13.36825 0.02534440243258 4.830 5.75 20.88 0.000917
The distance increases rapidly and, between 13:00-17:00, will reduce
the SNR/RTT by about 37%.
- - - - - - - - - -
JPL/Horizons solution 55, # obs: 187 (2001-2021)
2021 Feb 25
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2021-Mar-15 00:00 *m 199.97908 -34.48664 0.13340757508848 4.581 0.72 2.61 0.001981
2021-Mar-16 00:00 *m 201.13311 -34.95640 0.11357781500801 5.481 1.09 3.96 0.001965
2021-Mar-17 00:00 *m 202.77555 -35.58350 0.09382387924990 6.786 1.87 6.79 0.001928
2021-Mar-18 00:00 *m 205.31652 -36.47674 0.07418196130758 8.838 3.49 12.70 0.001852
2021-Mar-19 00:00 *m 209.77909 -37.85440 0.05474555733708 12.480 7.37 26.78 0.001692
2021-Mar-20 00:00 *m 219.50105 -40.11691 0.03581917806821 20.308 19.49 70.85 0.001309
2021-Mar-21 00:00 *m 250.38185 -41.49131 0.01895650357409 40.826 76.00 276.24 0.000636
2021-Mar-22 00:00 *m 321.20310 -7.78469 0.01501786108083 19.463 39.33 142.93 0.003573
2021-Mar-23 00:00 *m 349.33432 16.61407 0.02969687081035 11.511 10.81 39.28 0.003520
2021-Mar-24 00:00 *m 358.43924 23.19719 0.04826957443379 9.402 5.04 18.33 0.003269
2021-Mar-25 00:00 *m 2.68699 25.89306 0.06762002110188 7.462 2.30 8.35 0.003153
Uncertainties at hourly intervals on March 21:
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta POS_3sigma DOP_S_3sig DOP_X_3sig RT_delay_3sig
2021-Mar-21 12:00 286.98096 -31.72584 0.01387587345150 47.154 116.47 423.30 0.002138
2021-Mar-21 13:00 N 290.33767 -30.04975 0.01369575545218 46.022 114.88 417.52 0.002304
2021-Mar-21 14:00 * 293.64679 -28.24596 0.01356479409771 44.520 111.91 406.75 0.002467
2021-Mar-21 15:00 * 296.88862 -26.33077 0.01348455285415 42.664 107.59 391.02 0.002624
2021-Mar-21 16:00 * 300.04606 -24.32434 0.01345606160828 40.487 101.98 370.65 0.002775
Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination:
2001 FO32
JPL/Horizons solution 60
Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta APmag S-brt S-O-T /r T-O-M/MN_Illu%
2021-Mar-01 00:00 194.82260 -31.69416 0.41640994263004 17.831 3.762 129.8148 /L 36.3/ 96.1371
2021-Mar-02 00:00 195.01816 -31.83621 0.39585583476924 17.699 3.740 130.4554 /L 29.0/ 90.4644
2021-Mar-03 00:00 195.22040 -31.97993 0.37535618637630 17.562 3.718 131.0871 /L 27.3/ 82.5449
2021-Mar-04 00:00 195.43111 -32.12595 0.35491032662538 17.419 3.695 131.7085 /L 32.0/ 72.8856
2021-Mar-05 00:00 195.65251 -32.27509 0.33451757492694 17.268 3.673 132.3176 /L 40.8/ 62.1001
2021-Mar-06 00:00 195.88745 -32.42836 0.31417723471376 17.109 3.650 132.9122 /L 51.5/ 50.8328
2021-Mar-07 00:00 196.13955 -32.58708 0.29388858553939 16.942 3.627 133.4893 /L 62.9/ 39.7003
2021-Mar-08 00:00 196.41358 -32.75300 0.27365088096452 16.765 3.603 134.0452 /L 74.5/ 29.2547
2021-Mar-09 00:00 196.71583 -32.92841 0.25346336054402 16.576 3.580 134.5748 /L 86.1/ 19.9649
2021-Mar-10 00:00 197.05484 -33.11646 0.23332528640079 16.374 3.557 135.0716 /L 97.5/ 12.2068
2021-Mar-11 00:00 197.44243 -33.32146 0.21323602052385 16.157 3.534 135.5264 /L 108.6/ 6.2572
2021-Mar-12 00:00 197.89537 -33.54949 0.19319517124387 15.922 3.512 135.9264 /L 119.3/ 2.2907
2021-Mar-13 00:00 198.43836 -33.80939 0.17320286301167 15.665 3.490 136.2528 /L 129.3/ 0.3795
2021-Mar-14 00:00 199.10913 -34.11432 0.15326023906042 15.382 3.470 136.4770 /L 138.3/ 0.5010
2021-Mar-15 00:00 199.96845 -34.48482 0.13337043545259 15.066 3.452 136.5535 /L 145.8/ 2.5512
2021-Mar-16 00:00 201.12060 -34.95443 0.11354059438600 14.708 3.438 136.4045 /L 150.9/ 6.3649
2021-Mar-17 00:00 202.76051 -35.58144 0.09378643098761 14.294 3.431 135.8861 /L 152.8/ 11.7374
2021-Mar-18 00:00 205.29802 -36.47482 0.07414403649040 13.803 3.437 134.6992 /L 151.6/ 18.4440
2021-Mar-19 00:00 209.75592 -37.85348 0.05470670236993 13.199 3.469 132.1134 /L 148.9/ 26.2532
2021-Mar-20 00:00 219.47443 -40.12032 0.03577855042384 12.437 3.570 125.8294 /L 148.2/ 34.9318
2021-Mar-21 00:00 250.40262 -41.50477 0.01891441262244 11.668 3.935 105.1078 /L 159.7/ 44.2407
2021-Mar-22 00:00 321.33457 -7.69546 0.01500757528082 15. 6. 40.8645 /L 133.9/ 53.9226
2021-Mar-23 00:00 349.40192 16.65430 0.02971279450469 21. 9. 20.1809 /L 108.9/ 63.6834
2021-Mar-24 00:00 358.48045 23.21743 0.04829204767280 21. 8. 22.2886 /L 109.6/ 73.1709
2021-Mar-25 00:00 2.71624 25.90592 0.06764488144147 21. 8. 24.1339 /L 116.4/ 81.9587
Setups
2001 FO32:
For a rotation period of 40 h and a diameter of about 0.56 km,
the bandwidth could be about 1 Hz for an equatorial view.
Lightcurve observations indicate that the shape is elongated, so the
bandwidth could be double or 1/2 of this value.
CW setup:
--------------------------------------------
TX polarization RCP
RCV polarization LCP & RCP
Frequency hops: no hopping
Bandwidth: 5000 Hz
TXoffset +500 Hz
FFT 25000 for 0.2 Hz resolution
Ranging setups:
--------------------------------------------
10-usec
baud 10 usec
code 127
PRP 1270 usec
ncoh 1
bandwidth 787 Hz
FFT 128
resolution 6.15 Hz
TXoffset +100 Hz (echo in column 80)
--------------------------------------------
11-usec
baud 11 usec
code 127
PRP 1397 usec
ncoh 1
bandwidth 716 Hz
FFT 128
resolution 5.6 Hz
TXoffset +100 Hz (echo in column 82)
---------------------------------------------
1-usec
baud 1 usec
code 255
ncoh 8
bandwidth 245 Hz
FFT 128
resolution 3.8 Hz
TXoffset +50 Hz (echo in column 116)
---------------------------------------------
1/4 usec
baud 0.25 usec
code 127
ncoh 500
bandwidth 63.0 Hz
FFT 1024
resolution 0.06 Hz
TXoffset +10 Hz
---------------------------------------------
1/8 usec
baud 0.125 usec
code 127
ncoh 1000
bandwidth 63.0 Hz
FFT 1024
resolution 0.06 Hz
TXoffset +10 Hz
---------------------------------------------
NOTE: Data should be moved to the appropriate subdirectories in
aardvark:/export/data0/a231937/raw/
OSOD and predicts are on aardvark:
POINTING
...Not yet available...
Transmit offsets are given in millidegrees.
PRDX.OUT.14f-14-14.s??
TRANSMITTER: STATION #14, RECEIVER: STATION #14
RECEIVER U.T. RANGE DOPPLER LHA DEC RA EL
==============================================================================
-----------------------------------------------------
-----------------------------------------------------
Dr. Lance A. M. Benner | PHONE: (818) 354-7412
Mail Stop 183-601 | FAX: (818) 393-4445
Jet Propulsion Laboratory | email: lance.benner@jpl.nasa.gov
California Institute of Technology | Plan: To live long and prosper
Pasadena, CA 91109-8099
https://echo.jpl.nasa.gov/asteroids/2001FO32/2001FO32.2021.goldstone.planning.html
Asteroid Radar Astronomy