Goldstone Radar Observations Planning: 99942 Apophis in 2021


Background


99942 Apophis (2004 MN4) is one of the most important near-Earth asteroids ever discovered.  It will make a very close 
Earth approach on Friday, April 13, 2029 when it will pass within 0.1 lunar distances, which is only 
a few Earth radii above Earth's surface.  This will be the closest approach by something this large currently known,
Apophis will be visible to the naked eye for several hours, and Earth tides will probably change its spin state. 

Apophis was discovered in June of 2004, observed briefly, and then lost until it was serendipitously 
recovered in December of 2004.  Apophis has been observed with radar in January 2005 (Arecibo), August 2005 (Arecibo), 
August 2006 (Arecibo), and from December 2012-March 2013 (Goldstone and Arecibo).

In 2021, Apophis will make a relatively distant approach to Earth at about 0.113 au in March, when 
it will be a weak radar target at Goldstone and a somewhat stronger target at Arecibo.
Goldstone observations of Apophis are scheduled on March 3 - 14 and should provide echo power spectra and
ranging observations.  Observations on some dates overlap times for 2015 BY310 and 1999 RM45.  
We may also request time at Green Bank to receive echoes from Goldstone transmissions.

Time was requested at Arecibo, where SNRs would have been strong enough to obtain coarse-resolution 
delay-Doppler images.  However, radar observations at Arecibo will not occur because the observatory 
is being decommissioned.
 
Apophis has been observed at a variety of optical wavelengths and some of its key physical properties 
have been estimated.  Infrared radiometry by Delbo et al. (2007) suggests that the diameter is about 270 meters 
and that the optical albedo is about 0.3.  Mueller et al. (2014) estimated a diameter of about 375 meters.
Vis-IR spectroscopy reported by Binzel et al. (2009) places Apophis 
in the Sq-class.  Photometry obtained by Behrend et al. (unpublished) revealed a slow rotation period of 30.4 hours 
and a large lightcurve amplitude of ~1.0 mag that suggests a very elongated shape.  More detailed photometry reported
by Pravec et al. (2014) established that Apophis is a non-principal axis rotator with fundamental periods of about 
30.6 hours and ~11 days.  Published estimates of the thermal inertia span 
an order of magnitude and have large fractional uncertainties.
Goldstone and Arecibo radar observations in 2013 confirm that Apophis is elongated, 
are consistent with the NPA spin state reported by Pravec et al., strongly suggest that the shape is bifurcated, 
and yield an effective diameter of about 0.34 km.

The principal source of orbital uncertainty for Apophis
is the acceleration due to the Yarkovsky effect, a non-gravitational perturbation that is a function of the asteroid's
spin state, thermal inertia, mass, shape, and dimensions.  
Recently Greenberg et al. (2020) and Tholen and Farnocchia (2020) reported detections of the Yarkovsky effect
at the ~2-sigma and many-sigma levels.  Tholen and Farnocchia predict ~170 m/year of deflection due to this effect,
so it is possible that we may see a somewhat larger time-delay correction to the predicts than usual.  

The 2021 radar observations should improve knowledge of the spin state and shape; smaller uncertainties in
these physical properties will help reveal changes due to Earth tides following the flyby in 2029 and *might*
enable prediction of the orientation of the asteroid after the 2029 encounter.
The primary objectives with radar observations in 2021 will be to estimate ranges and obtain echo power spectra to help 
reduce uncertainties in the orbit, spin state, and 3D shape.

Apophis will pass through the observing window of NASA's NEOWISE spacecraft in December 2020 and April 2021,
which should facilitate new estimation of the diameter, and by comparison with the 
3D model estimated from radar data and photometry, provide calibration for the diameter estimated from NEOWISE data.

The 2021 Goldstone observations of Apophis will be part of a planetary defense campaign under the auspices of the
International Asteroid Warning Network (IAWN) with support from NASA's Planetary Defense Coordination Office:
http://www.iawn.net/obscamp/Apophis/

The 2021 encounter by Apophis is the last close enough for radar observations at Goldstone until 2029,
although Apophis will also be a weak radar target at Arecibo in September, 2028 when additional
radar ranging measurements and CW echoes could be obtained.

Apophis has been classified as a "Potentially Hazardous Asteroid" (PHA) by the IAU's Minor Planet Center.


Orbital and Physical Characteristics  
Name                     Apophis 
Asteroid number          99942
Provisional designation  2004 MN4
Discoverers              Roy Tucker, David Tholen, and Fabrizio Bernardi
Discovery date           2004 June 19

Close approach distance  0.11265 au  (43.8 lunar distances or about 17 million km)
Close approach date      2021 Mar 6

Orbit type               Aten
semimajor axis           0.922 au
eccentricity             0.191
inclination              3.3 deg                 
Orbital period           0.886 years              
perihelion distance      0.746 au
aphelion distance        1.099 au
MOID                     0.00032 au

absolute magnitude (H)   19.7
diameter                 0.34+-0.04 km                                    Brozovic et al. 2018
                         0.27+-0.06 km                                    Delbo et al. 2007
                         0.375+0.014-0.010 km                             Mueller et al. 2014
                         0.380-0.393 km                                   Licandro et al. 2016
optical albedo           0.23                  
rotation period          30.56 and ~11 days (non-principal axis rotator); Pravec et al. 2014
lightcurve amplitude     0.95 mag                                         Pravec et al. 2014
pole direction           NPA rotator: no fixed pole direction
spectral class           Sq
Thermal inertia          600 +200 -350 mks units  Mueller et al. 2014
                         50-500        mks units  Licandro et al. 2016
                         100 +240 -100 mks units  Yu et al. 2017
PHA?                     Yes

Last update: 2021 March  9

Discovery M.P.E.C.


Apophis discovery MPEC
https://www.minorplanetcenter.net/mpec/K04/K04Y25.html


SNR Calculations

Goldstone SNRs
Assumptions: D = 0.34 km,  P = 30.6 h,  OC albedo = 0.24, Ptx = 450 kW, Tsys = 17 K

w  DOY start date          window        RA, dec   dist  runs SNR/day SNR/run
 7  46    2021 Feb 15     05:48-12:05   163, -18  0.131    87    12     1
 7  47    2021 Feb 16     05:39-11:59   162, -18  0.129    89    13     1
 7  48    2021 Feb 17     05:29-11:52   161, -18  0.127    91    14     1
 7  49    2021 Feb 18     05:19-11:46   160, -17  0.126    93    14     1
 7  50    2021 Feb 19     05:10-11:40   159, -17  0.124    95    15     1
 7  51    2021 Feb 20     04:59-11:34   158, -16  0.123    97    16     2
 7  52    2021 Feb 21     04:49-11:28   156, -16  0.121    99    17     2
 8  53    2021 Feb 22     04:38-11:22   155, -16  0.120   101    18     2
 8  54    2021 Feb 23     04:28-11:16   154, -15  0.119   103    19     2
 8  55    2021 Feb 24     04:17-11:10   153, -14  0.118   106    20     2
 8  56    2021 Feb 25     04:06-11:04   152, -14  0.117   108    21     2
 8  57    2021 Feb 26     03:55-10:58   151, -13  0.116   110    21     2
 8  58    2021 Feb 27     03:44-10:52   150, -13  0.115   112    22     2   Overlaps 1999 RM45
 8  59    2021 Feb 28     03:32-10:46   148, -12  0.114   114    23     2   Overlaps 1999 RM45
 9  60    2021 Mar 01     03:21-10:40   147, -11  0.114   116    24     2   Overlaps 1999 RM45
 9  61    2021 Mar 02     03:10-10:35   146, -11  0.113   118    24     2   Overlaps 1999 RM45
 9  62    2021 Mar 03     02:58-10:29   145, -10  0.113   120    25     2   Scheduled 06:10-07:40.  GBT scheduled. 
 9  63    2021 Mar 04     02:47-10:23   144,  -9  0.113   122    25     2   Scheduled 06:50-08:05.  GBT scheduled. 
 9  64    2021 Mar 05     02:36-10:18   143,  -8  0.113   124    26     2   Scheduled 07:30-10:15.  GBT scheduled. 
 9  65    2021 Mar 06     02:25-10:12   142,  -8  0.113   125    26     2   Scheduled 02:25-09:20.  GBT scheduled. 
 9  66    2021 Mar 07     02:13-10:07   141,  -7  0.113   127    26     2   Scheduled 02:15-08:55.  GBT scheduled. 
10  67    2021 Mar 08     02:02-10:02   140,  -6  0.113   128    26     2   Scheduled 03:15-07:15.  GBT scheduled. 
10  68    2021 Mar 09     01:52-09:56   139,  -5  0.113   129    26     2   Scheduled 01:30-09:55.  GBT scheduled. 
10  69    2021 Mar 10     01:41-09:51   138,  -4  0.114   130    26     2   Scheduled 01:45-08:20.  GBT scheduled. 
10  70    2021 Mar 11     01:30-09:46   137,  -4  0.114   131    26     2   Scheduled 05:25-09:45.  GBT scheduled. 
10  71    2021 Mar 12     01:20-09:41   136,  -3  0.115   132    26     2   Scheduled 03:20-06:45.  GBT scheduled. 
10  72    2021 Mar 13     01:10-09:36   135,  -2  0.115   132    25     2   Scheduled 01:10-06:55.  GBT scheduled. 
10  73    2021 Mar 14     01:00-09:31   134,  -1  0.116   133    25     2   Scheduled 03:40-06:50.  GBT scheduled. 
11  74    2021 Mar 15     00:50-09:26   133,   0  0.117   133    25     2   
11  75    2021 Mar 16     00:40-09:22   132,   0  0.117   134    24     2
11  76    2021 Mar 17     00:31-09:17   131,  +1  0.118   134    23     2
11  77    2021 Mar 18     00:22-09:13   131,  +2  0.119   134    23     2
11  78    2021 Mar 19     00:13-09:08   130,  +3  0.120   134    22     2
11  79    2021 Mar 20     00:04-09:04   129,  +3  0.121   134    22     2
11  80-81 2021 Mar 20-21  23:55-08:59   129,  +4  0.123   134    21     2
11  81-82 2021 Mar 21-22  23:47-08:55   128,  +5  0.124   133    20     2
12  82-83 2021 Mar 22-23  23:38-08:51   127,  +6  0.125   133    20     2
12  83-84 2021 Mar 23-24  23:30-08:47   127,  +6  0.126   133    19     2
12  84-85 2021 Mar 24-25  23:22-08:42   126,  +7  0.127   132    18     1
12  85-86 2021 Mar 25-26  23:15-08:38   126,  +7  0.129   132    18     1
12  86-87 2021 Mar 26-27  23:07-08:34   125,  +8  0.130   131    17     1
12  87-88 2021 Mar 27-28  23:00-08:30   125,  +9  0.131   131    16     1
12  88-89 2021 Mar 28-29  22:53-08:27   125,  +9  0.133   130    16     1

Goldstone SNRs assume full power (450 kW) with two klystrons.

Sky motion during the Goldstone observations: ~14 degrees.

Reception of echoes at Green Bank will increase the SNRs by a factor of about 2.3.

Colleagues at the Sardinia Radio Telescope might eavesdrop on
echoes from Goldstone transmissions.  If the SRT has system temperatures similar to those
at DSS-14, namely ~15-20 K, then all else being equal, the SNRs should be about
83% as strong as at DSS-14.  This assumes that DSS-14 cycles between transmitting
and receiving and does not transmit continuously.  SRT can receive down to 
5 degrees above the horizon.  It appears that the SRT's C-band Tsys is about 29 K and the 
gain is about 0.64 K/Jy, so if values at X-band are similar, 
this would decrease the SNRs by close to a factor of four relative to values at DSS-14.



Apophis ARECIBO SNRs

 Radar observations of Apophis at Arecibo will not be possible 

Assumptions: D = 0.34 km, P = 30.6 h, gain = 7 K/Jy, Ptx = 700 kW, Tsys = 25 K, radar albedo = 0.2.
start date    window       RA, dec   dist   runs      SNR/day  SNR/run
2021 Mar 14  01:47-02:05   134,  -1  0.116     4         18         9
2021 Mar 15  01:24-02:12   133,   0  0.117    12         34        10
2021 Mar 16  01:09-02:14   132,   0  0.117    16         43        12
2021 Mar 17  00:55-02:13   131,  +1  0.118    19         50        13
2021 Mar 18  00:43-02:11   131,  +2  0.119    22         55        13
2021 Mar 19  00:32-02:09   130,  +3  0.120    24         60        14
2021 Mar 20  00:22-02:06   129,  +3  0.121    25         64        15
2021 Mar 21  00:12-02:02   129,  +4  0.122    27         67        15
2021 Mar 22  00:03-01:59   128,  +5  0.124    28         67        14
2021 Mar 22  23:54-01:55   127,  +5  0.125    29         67        14
2021 Mar 23  23:45-01:52   127,  +6  0.126    30         66        13
2021 Mar 24  23:37-01:48   126,  +7  0.127    30         65        13
2021 Mar 25  23:29-01:44   126,  +7  0.129    31         64        12
2021 Mar 26  23:22-01:40   125,  +8  0.130    32         63        12
2021 Mar 27  23:15-01:36   125,  +9  0.131    32         61        12
2021 Mar 28  23:08-01:31   125,  +9  0.133    32         59        11
2021 Mar 29  23:01-01:27   124, +10  0.134    33         58        11
2021 Mar 30  22:55-01:23   124, +10  0.135    33         56        10
2021 Mar 31  22:48-01:19   124, +11  0.137    33         54        10
2021 Apr 01  22:42-01:15   123, +11  0.138    33         53        10
2021 Apr 02  22:36-01:10   123, +12  0.139    33         51         9
2021 Apr 03  22:31-01:06   123, +12  0.141    33         49         9
2021 Apr 04  22:25-01:02   122, +13  0.142    33         48         9
2021 Apr 05  22:19-00:58   122, +13  0.143    33         46         8
2021 Apr 06  22:14-00:54   122, +14  0.144    33         45         8
2021 Apr 07  22:09-00:49   122, +14  0.146    33         44         8
2021 Apr 08  22:04-00:45   122, +15  0.147    33         42         8
2021 Apr 09  21:59-00:41   122, +15  0.148    33         41         8
2021 Apr 10  21:54-00:37   121, +16  0.150    32         40         7
2021 Apr 11  21:49-00:33   121, +16  0.151    32         38         7
2021 Apr 12  21:44-00:28   121, +17  0.152    32         37         7
2021 Apr 13  21:40-00:24   121, +17  0.153    32         36         7
2021 Apr 14  21:35-00:20   121, +17  0.154    30         34         7
2021 Apr 15  21:31-00:16   121, +18  0.155    30         33         6
2021 Apr 16  21:26-00:12   121, +18  0.156    30         32         6
2021 Apr 17  21:22-00:08   121, +19  0.157    30         32         6
2021 Apr 18  21:18-00:04   121, +19  0.158    30         31         6
2021 Apr 19  21:13-23:59   120, +19  0.159    30         31         6
2021 Apr 20  21:09-23:55   120, +20  0.160    31         31         6
2021 Apr 21  21:05-23:51   120, +20  0.161    31         30         6
2021 Apr 22  21:01-23:47   120, +20  0.162    30         29         6
2021 Apr 23  20:57-23:42   120, +21  0.162    30         29         5
2021 Apr 24  20:53-23:38   120, +21  0.163    30         28         5
2021 Apr 25  20:49-23:34   120, +21  0.164    30         28         5
2021 Apr 26  20:45-23:29   120, +22  0.164    30         27         5
2021 Apr 27  20:41-23:25   120, +22  0.165    30         27         5
2021 Apr 28  20:36-23:21   120, +22  0.166    29         26         5
2021 Apr 29  20:32-23:16   120, +23  0.166    29         26         5
2021 Apr 29  20:32-23:16   120, +23  0.166    29         26         5
2021 Apr 30  20:28-23:12   120, +23  0.167    29         26         5
2021 May 01  20:24-23:07   120, +23  0.167    29         25         5
2021 May 02  20:20-23:02   119, +24  0.167    29         25         5
2021 May 03  20:16-22:57   119, +24  0.168    29         25         5
2021 May 04  20:12-22:53   119, +24  0.168    28         24         5
2021 May 05  20:08-22:48   119, +25  0.168    28         24         5
2021 May 06  20:04-22:43   119, +25  0.169    28         24         5
2021 May 07  19:59-22:38   119, +25  0.169    28         24         5
2021 May 08  19:55-22:32   118, +26  0.169    28         24         5
2021 May 09  19:51-22:27   118, +26  0.169    27         23         5
2021 May 10  19:47-22:22   118, +26  0.169    27         23         5
2021 May 11  19:42-22:16   118, +27  0.169    27         23         5
2021 May 12  19:38-22:10   118, +27  0.170    27         23         5
2021 May 13  19:33-22:05   117, +28  0.170    26         23         5
2021 May 14  19:29-21:59   117, +28  0.170    26         22         5
2021 May 15  19:24-21:53   117, +28  0.170    26         22         5
2021 May 16  19:20-21:46   116, +29  0.170    26         22         5
2021 May 17  19:15-21:40   116, +29  0.170    25         22         5
2021 May 18  19:10-21:33   115, +29  0.170    25         22         5
2021 May 19  19:06-21:27   115, +30  0.170    25         22         5
2021 May 20  19:01-21:20   114, +30  0.170    24         21         5
2021 May 21  18:56-21:13   114, +30  0.170    24         21         5
2021 May 22  18:51-21:05   113, +31  0.170    24         21         5
2021 May 23  18:45-20:58   113, +31  0.170    23         20         5
2021 May 24  18:40-20:50   112, +31  0.170    23         20         5
2021 May 25  18:35-20:42   111, +32  0.170    22         20         5
2021 May 26  18:29-20:34   111, +32  0.171    22         19         5
2021 May 27  18:24-20:26   110, +32  0.171    21         19         5
2021 May 28  18:18-20:17   109, +33  0.171    21         18         5
2021 May 29  18:12-20:08   108, +33  0.171    20         17         5
2021 May 30  18:06-20:00   107, +33  0.172    19         17         4
2021 May 31  18:00-19:51   106, +34  0.172    19         16         4
2021 Jun 01  17:54-19:41   106, +34  0.173    18         15         4
2021 Jun 02  17:48-19:32   105, +34  0.174    18         14         4
2021 Jun 03  17:41-19:23   104, +34  0.175    17         13         4
2021 Jun 04  17:35-19:13   103, +35  0.175    16         13         4
2021 Jun 05  17:28-19:04   102, +35  0.177    16         12         3

The SNRs above assume a gain that is about 30% lower than in 2013 due to damage
sustained from Hurricane Maria in 2017.  That reduced the SNRs by about a factor of two.

...Radar observations at Arecibo will not be possible...


Track Assignments


DOY    BOA   BOT   EOT   EOA
58     0450  0620  0750  0820  GSSR AST 1999 RM45    Overlaps Apophis entirely
59     0410  0540  0745  0815  GSSR AST 1999 RM45    Overlaps Apophis entirely
59     2055  2225  2355  0025  GSSR AST 2007 BG
60     0440  0610  0840  0910  GSSR AST 1999 RM45    Overlaps Apophis entirely
60           1100  1540        CSSR AST 1999 RM45  DSS-36/ATCA (S. Horiuchi et al.)
61     0400  0530  0715  0745  GSSR AST 1999 RM45    Overlaps Apophis entirely
61           1035  1550        CSSR AST 1999 RM45  DSS-34/ATCA (S. Horiuchi et al.)
62     0440  0610  0740  0810  GSSR AST APOPHIS
63     0520  0650  0805  0835  GSSR AST APOPHIS
64     0600  0730  1015  1045  GSSR AST APOPHIS
64-65  1910  2040  0920  0950  GSSR AST 1999 RM45, 2015 BY310, and APOPHIS 
66           0005  0855  0925  GSSR AST 2015 BY310 and APOPHIS  
67     0145  0315  0715  0745  GSSR AST 2015 BY310 and APOPHIS  
68     0000  0130  0955  1025  GSSR AST 2015 BY310 and APOPHIS
68-69  2150  2320  0820  0850  GSSR AST 2015 BY310 and APOPHIS  
70     0355  0525  0945  1015  GSSR AST APOPHIS
70     1045  1215  1415  1445  GSSR AST 2004 FX31
71     0150  0320  0645  0715  GSSR AST APOPHIS
71-72  2340  0110  0655  0725  GSSR AST APOPHIS
73     0210  0340  0650  0720  GSSR AST APOPHIS

Goldstone tracks:                                        
                                                                    Apophis
      UT                   UT         PST               Duration RTT Rot'n            Green Bank
DOY   Date      Target     TX Window  TX Window           hh:mm   s   deg   Observer  Schedule (may include GSSR precal time)
58    Feb 27    1999 RM45  0620-0750  2220-2350 Feb 26     1:30   46         Benner
58    Feb 27    Apophis    0620-0750  2220-2350 Feb 26     1:30  115   18   

59    Feb 28    1999 RM45  0540-0745  2140-2345 Feb 27     2:05   36         Benner
59    Feb 28    Apophis    0540-0745  2140-2345 Feb 27     2:05  114   24       

59    Feb 28    2007 BG    2225-2355  1425-1555 Feb 28     1:30   60         Benner

60    Mar  1    1999 RM45  0610-0840  2210-0040 Feb 28- 1  2:30   27         Naidu 
60    Mar  1    Apophis    0610-0840  2210-0040 Feb 28- 1  2:30  114   29       

60    Mar  1    1999 RM45  1100-1540  0300-0740 Mar  1     4:40              Horiuchi et al.     DSS-36/ATCA 80 kW 7190 MHz (4.2 cm)

61    Mar  2    1999 RM45  0530-0715  2130-2315 Mar  1     1:45   21         Brozovic
61    Mar  2    Apophis    0530-0715  2130-2315 Mar  1     1:45  113   21     

61    Mar  2    1999 RM45  1035-1550  0235-0750 Mar  2     5:15              Horiuchi et al.     DSS-34/ATCA 20 kW 7190 MHz (4.2 cm)

62    Mar  3    Apophis    0610-0740  2210-2340 Mar  2     1:30  113   18    Brozovic  0540-0740 GBT  

63    Mar  4    Apophis    0650-0805  2250-0005 Mar  3- 4  1:15  113   15    Naidu     0620-0750 GBT  

64    Mar  5    Apophis    0730-1015  2330-0215 Mar  4- 5  2:45  113   32    Naidu     0700-0745 GBT

64-65 Mar  5- 6 1999 RM45  2040-0205  1240-1805 Mar  5     6:05   40         Brozovic
64-65 Mar  5- 6 2015 BY310 2300-0635  1500-2235 Mar  5     7:35   41
65    Mar  6    Apophis    0225-0920  1825-0120 Mar  5- 6  6:55  113   81              0155-0740 GBT  

66    Mar  7    1999 RM45  0005-0140  1605-1740 Mar  6     1:35   51         Naidu           
66    Mar  7    2015 BY310 0005-0600  1605-2200 Mar  6     5:55   39
66    Mar  7    Apophis    0215-0855  1815-0055 Mar  6- 7  6:40  113   79              0145-0735 GBT                      

67    Mar  8    Apophis    0315-0715  1915-2315 Mar  7     4:00  113   47    Brozovic  0245-0715 GBT
67    Mar  8    2015 BY310 0315-0515  1915-2115 Mar  7     2:00   38       

68    Mar  9    Apophis    0130-0955  1730-0155 Mar  8- 9  8:25  113   97    Naidu     0130-0700 GBT                     
68    Mar  9    2015 BY310 0130-0430  1730-2030 Mar  8     3:00   37

68-69 Mar  9-10 2015 BY310 2320-0330  1520-1930 Mar  9     4:10   36         Naidu               Overlaps 2021 CF6
69    Mar 10    Apophis    0145-0820  1745-0020 Mar  9-10  6:35  114   78              0115-0720 GBT 

70    Mar 11    Apophis    0525-0945  2125-0145 Mar 10-11  4:20  114   51    Brozovic  0455-0715 GBT  

70    Mar 11    2004 FX31  1215-1415  0415-0615 Mar 11     2:00   93         Benner              Overlaps 2021 EB1 and 2021 CF6

71    Mar 12    Apophis    0320-0645  1920-2245 Mar 11     3:25  115   40    Benner    0250-0645 GBT  

72    Mar 13    Apophis    0110-0655  1710-2355 Mar 12     5:45  115   68    Benner    0040-0655 GBT  

73    Mar 14    Apophis    0340-0650  1940-2350 Mar 13     3:10  116   37    Brozovic  0310-0650 GBT  

Rotation refers *only* to rotation during BOT-EOT times and not during precal.

The Green Bank Telescope schedule corresponds to times requested.  Green Bank tracks
start on 15 minute markers, so some of the start times above could change by up to +-10 minutes.


Goldstone/Sardinia Radio Telescope Overlap
        SRT rise/set  DSS-14 Overlap
Mar  2- 3  1725-0320    None
Mar  3- 4  1713-0314    None
Mar  4- 5  1702-0308    None
Mar  5- 6  1651-0303    0225-0303 
Mar  6- 7  1640-0257    0215-0257
Mar  7- 8  1629-0252    None
Mar  8- 9  1618-0246    0130-0246
Mar  9-10  1608-0241    0145-0241
Mar 10-11  1557-0236    None
Mar 11-12  1547-0231    None
Mar 12-13  1536-0226    0110-0226
Mar 13-14  1526-0221    None

Note: Daylight saving time starts a few hours after the March 14 track ends.



Uncertainties

Apophis
JPL/Horizons solution 204,  # obs: 5834 (2004-2021)
radar(18 delay,30 Dop.)
2021 March 5.  
Solution 204 includes one new Doppler and one new range from March, 2021.
Jon Giorgini reports that new astrometry reported since solution 202 reduced the plane-of-sky pointing
uncertainty by about 84%.
Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2021-Mar-01 00:00 *   147.68682 -11.49126 0.11401518628162      0.088        0.04        0.15       0.000007
 2021-Mar-02 00:00 *   146.52690 -10.78211 0.11353105258487      0.089        0.04        0.15       0.000005
 2021-Mar-03 00:00 *   145.37435 -10.05141 0.11315394773905      0.090        0.04        0.15       0.000004
 2021-Mar-04 00:00 *   144.23229  -9.30141 0.11288368814041      0.091        0.04        0.15       0.000003
 2021-Mar-05 00:00 *   143.10380  -8.53451 0.11271970343415      0.091        0.04        0.15       0.000003
 2021-Mar-06 00:00 *   141.99186  -7.75325 0.11266099553850      0.092        0.04        0.15       0.000003
 2021-Mar-07 00:00 *   140.89933  -6.96022 0.11270610653811      0.092        0.04        0.15       0.000004
 2021-Mar-08 00:00 *   139.82890  -6.15809 0.11285310039885      0.092        0.04        0.15       0.000005
 2021-Mar-09 00:00 *   138.78307  -5.34952 0.11309956021191      0.092        0.04        0.14       0.000006
 2021-Mar-10 00:00 *   137.76411  -4.53715 0.11344260048551      0.091        0.04        0.14       0.000008
 2021-Mar-11 00:00 *   136.77404  -3.72356 0.11387889297712      0.091        0.04        0.14       0.000009
 2021-Mar-12 00:00 *m  135.81462  -2.91118 0.11440470419302      0.090        0.04        0.14       0.000010
 2021-Mar-13 00:00 *m  134.88732  -2.10234 0.11501594243403      0.090        0.04        0.13       0.000012
 2021-Mar-14 00:00 *m  133.99333  -1.29917 0.11570821189049      0.089        0.04        0.13       0.000013
 2021-Mar-15 00:00 *m  133.13354  -0.50361 0.11647687087092      0.088        0.03        0.13       0.000014

JPL/Horizons solution 202, # obs: 5022 (2004-2021)
2021 Feb 18
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2021-Mar-01 00:00 *   147.68683 -11.49126 0.11401518625856      0.253        0.14        0.52       0.000032
 2021-Mar-02 00:00 *   146.52691 -10.78212 0.11353105178001      0.252        0.14        0.52       0.000036
 2021-Mar-03 00:00 *   145.37436 -10.05142 0.11315394615046      0.252        0.14        0.52       0.000040
 2021-Mar-04 00:00 *   144.23230  -9.30141 0.11288368576855      0.251        0.14        0.52       0.000045
 2021-Mar-05 00:00 *   143.10381  -8.53452 0.11271970028206      0.249        0.14        0.51       0.000049
 2021-Mar-06 00:00 *   141.99187  -7.75325 0.11266099161156      0.246        0.14        0.51       0.000054
 2021-Mar-07 00:00 *   140.89934  -6.96023 0.11270610184409      0.244        0.14        0.50       0.000059
 2021-Mar-08 00:00 *   139.82891  -6.15809 0.11285309494772      0.240        0.14        0.49       0.000063
 2021-Mar-09 00:00 *   138.78307  -5.34953 0.11309955401582      0.236        0.13        0.48       0.000068
 2021-Mar-10 00:00 *   137.76411  -4.53716 0.11344259355855      0.232        0.13        0.47       0.000073
 2021-Mar-11 00:00 *   136.77405  -3.72356 0.11387888533516      0.227        0.13        0.46       0.000077
 2021-Mar-12 00:00 *m  135.81463  -2.91119 0.11440469585350      0.222        0.12        0.45       0.000081
 2021-Mar-13 00:00 *m  134.88733  -2.10234 0.11501593341572      0.217        0.12        0.43       0.000085
 2021-Mar-14 00:00 *m  133.99333  -1.29917 0.11570820221330      0.211        0.11        0.42       0.000090
 2021-Mar-15 00:00 *m  133.13355  -0.50362 0.11647686055568      0.206        0.11        0.40       0.000093
The one-sigma time delay uncertainty on March 3 is only a few times larger than the long axis 
of the asteroid.

JPL/Horizons solution 201, # obs: 4716 (2004-2021)
2021 Feb 10
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2021-Mar-01 00:00 *   147.68682 -11.49126 0.11401518908913      0.540        0.31        1.14       0.000055
 2021-Mar-02 00:00 *   146.52690 -10.78212 0.11353105509333      0.539        0.31        1.14       0.000066
 2021-Mar-03 00:00 *   145.37435 -10.05141 0.11315394994459      0.537        0.31        1.13       0.000077
 2021-Mar-04 00:00 *   144.23229  -9.30141 0.11288369004009      0.533        0.31        1.13       0.000088
 2021-Mar-05 00:00 *   143.10380  -8.53452 0.11271970502609      0.529        0.31        1.12       0.000099
 2021-Mar-06 00:00 *   141.99187  -7.75325 0.11266099682177      0.523        0.30        1.11       0.000110
 2021-Mar-07 00:00 *   140.89933  -6.96022 0.11270610751274      0.515        0.30        1.09       0.000121
 2021-Mar-08 00:00 *   139.82890  -6.15809 0.11285310106583      0.507        0.29        1.07       0.000131
 2021-Mar-09 00:00 *   138.78307  -5.34952 0.11309956057317      0.497        0.29        1.05       0.000142
 2021-Mar-10 00:00 *   137.76411  -4.53716 0.11344260054386      0.487        0.28        1.03       0.000152
 2021-Mar-11 00:00 *   136.77404  -3.72356 0.11387889273621      0.476        0.27        1.00       0.000162
 2021-Mar-12 00:00 *m  135.81462  -2.91119 0.11440470365727      0.464        0.27        0.97       0.000172
 2021-Mar-13 00:00 *m  134.88732  -2.10234 0.11501594160856      0.451        0.26        0.94       0.000181
 2021-Mar-14 00:00 *m  133.99333  -1.29917 0.11570821078105      0.437        0.25        0.91       0.000190
 2021-Mar-15 00:00 *m  133.13355  -0.50362 0.11647686948381      0.423        0.24        0.88       0.000199

JPL/Horizons solution 199, # obs: 4481 (2004-2015):
2020 Oct 20
This orbital solution does NOT include astrometry obtained in early 2020, which probably reduced
the uncertainties significantly.   The 2019-2020 astrometry is not yet available in the JPL/Horizons system.
 Date__(UT)__HR:MN     R.A._(a-appar)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2021-Mar-01 00:00 *   147.68716 -11.49140 0.11401507539835      3.152        1.83        6.64       0.000282
 2021-Mar-02 00:00 *   146.52724 -10.78226 0.11353091352722      3.146        1.83        6.65       0.000349
 2021-Mar-03 00:00 *   145.37468 -10.05156 0.11315378055695      3.133        1.83        6.63       0.000416
 2021-Mar-04 00:00 *   144.23262  -9.30156 0.11288349297021      3.112        1.82        6.60       0.000483
 2021-Mar-05 00:00 *   143.10413  -8.53467 0.11271948049851      3.084        1.80        6.55       0.000549
 2021-Mar-06 00:00 *   141.99218  -7.75340 0.11266074514455      3.048        1.78        6.48       0.000615
 2021-Mar-07 00:00 *   140.89965  -6.96037 0.11270582907456      3.005        1.76        6.39       0.000679
 2021-Mar-08 00:00 *   139.82921  -6.15824 0.11285279633161      2.955        1.73        6.28       0.000743
 2021-Mar-09 00:00 *   138.78337  -5.34967 0.11309923007869      2.898        1.69        6.15       0.000805
 2021-Mar-10 00:00 *   137.76440  -4.53731 0.11344224488922      2.836        1.65        6.01       0.000866
 2021-Mar-11 00:00 *   136.77433  -3.72371 0.11387851257853      2.769        1.61        5.85       0.000925
 2021-Mar-12 00:00 *m  135.81490  -2.91133 0.11440429970282      2.696        1.56        5.69       0.000982
 2021-Mar-13 00:00 *m  134.88759  -2.10248 0.11501551460443      2.620        1.52        5.51       0.001038
 2021-Mar-14 00:00 *m  133.99359  -1.29931 0.11570776150677      2.540        1.47        5.32       0.001092
 2021-Mar-15 00:00 *m  133.13379  -0.50375 0.11647639874306      2.457        1.41        5.14       0.001143


Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination: ...Recovery could happen by mid November, 2020... Date__(UT)__HR:MN R.A._(a-appar)_DEC. delta APmag S-brt S-O-T /r T-O-M/MN_Illu% 2020-Nov-15 00:00 166.12922 -2.78772 0.26147255929065 19.997 5.046 65.0159 /L 62.5/ 0.1220 2020-Nov-17 00:00 166.29626 -3.20093 0.26370969755451 19.938 5.010 66.7136 /L 91.3/ 4.6639 2020-Nov-19 00:00 166.51679 -3.62707 0.26568085920933 19.883 4.978 68.3559 /L 118.6/ 18.8668 2020-Nov-21 00:00 166.78438 -4.06473 0.26737672950775 19.832 4.950 69.9491 /L 143.3/ 38.0548 2020-Nov-23 00:00 167.09337 -4.51271 0.26878950383500 19.785 4.925 71.4989 /L 162.7/ 58.0290 2020-Nov-25 00:00 167.43857 -4.97003 0.26991259856883 19.740 4.903 73.0105 /L 159.8/ 75.9488 2020-Nov-27 00:00 167.81520 -5.43581 0.27074063458144 19.698 4.883 74.4887 /L 140.4/ 89.8600 2020-Nov-29 00:00 168.21875 -5.90927 0.27126939381820 19.656 4.864 75.9379 /L 118.6/ 98.1857 2020-Dec-01 00:00 168.64495 -6.38966 0.27149573158160 19.615 4.848 77.3626 /L 96.0/ 99.6593 2020-Dec-03 00:00 169.08966 -6.87628 0.27141753520462 19.575 4.832 78.7668 /L 72.8/ 93.6156 2020-Dec-05 00:00 169.54879 -7.36839 0.27103380249099 19.535 4.818 80.1545 /L 49.4/ 80.3429 2020-Dec-07 00:00 170.01831 -7.86524 0.27034484901268 19.494 4.805 81.5298 /L 26.9/ 61.2929 2020-Dec-09 00:00 170.49419 -8.36598 0.26935261952655 19.453 4.793 82.8966 /L 17.5/ 39.2368 2020-Dec-11 00:00 170.97247 -8.86970 0.26806108225031 19.411 4.781 84.2587 /L 36.9/ 18.4194 2020-Dec-13 00:00 171.44932 -9.37540 0.26647659292883 19.368 4.769 85.6199 /L 63.6/ 4.0429 2020-Dec-15 00:00 171.92112 -9.88201 0.26460786022000 19.323 4.758 86.9835 /L 91.1/ 0.1504 2020-Dec-17 00:00 172.38460 -10.38852 0.26246515148533 19.277 4.748 88.3525 /L 117.5/ 7.1476 2020-Dec-19 00:00 172.83687 -10.89409 0.26005908350592 19.229 4.737 89.7292 /L 141.4/ 21.9735 NEOWISE detection? 2020-Dec-21 00:00 173.27529 -11.39801 0.25739983607808 19.179 4.726 91.1160 /L 159.1/ 40.5890 2020-Dec-23 00:00 173.69727 -11.89971 0.25449705106045 19.128 4.716 92.5150 /L 157.2/ 59.7476 2020-Dec-25 00:00 174.10013 -12.39860 0.25136004035767 19.074 4.705 93.9286 /L 139.5/ 77.1206 2020-Dec-27 00:00 174.48103 -12.89411 0.24799795993091 19.018 4.694 95.3590 /L 118.4/ 90.7513 2020-Dec-29 00:00 174.83692 -13.38562 0.24441988309574 18.960 4.682 96.8088 /L 96.0/ 98.6948 2020-Dec-31 00:00 175.16445 -13.87242 0.24063487599569 18.899 4.671 98.2807 /L 72.8/ 99.1908 2021-Jan-01 00:00 175.31642 -14.11381 0.23866765477419 18.868 4.665 99.0258 /L 61.0/ 96.3041 2021-Jan-03 00:00 175.59422 -14.59195 0.23458983464220 18.803 4.652 100.5366 /L 38.0/ 84.3623 2021-Jan-05 00:00 175.83342 -15.06293 0.23032968262167 18.736 4.639 102.0777 /L 21.4/ 65.6315 2021-Jan-07 00:00 176.02919 -15.52532 0.22589916915335 18.665 4.626 103.6531 /L 29.7/ 43.3122 2021-Jan-09 00:00 176.17635 -15.97736 0.22131221144967 18.592 4.611 105.2670 /L 53.0/ 21.9020 2021-Jan-11 00:00 176.26950 -16.41699 0.21658481256224 18.515 4.596 106.9236 /L 79.1/ 6.2986 2021-Jan-13 00:00 176.30318 -16.84188 0.21173470966773 18.435 4.580 108.6269 /L 105.2/ 0.1093 2021-Jan-15 00:00 176.27203 -17.24959 0.20678054119359 18.351 4.562 110.3807 /L 129.7/ 4.0210 2021-Jan-17 00:00 176.17078 -17.63759 0.20174097635699 18.264 4.544 112.1886 /L 149.9/ 15.9298 2021-Jan-19 00:00 175.99405 -18.00320 0.19663432160132 18.174 4.524 114.0539 /L 156.6/ 32.6462 2021-Jan-21 00:00 175.73617 -18.34352 0.19147863166723 18.080 4.503 115.9801 /L 143.9/ 51.3045 2021-Jan-23 00:00 175.39112 -18.65525 0.18629199871160 17.983 4.480 117.9708 /L 124.2/ 69.6190 2021-Jan-25 00:00 174.95245 -18.93467 0.18109277918600 17.882 4.456 120.0296 /L 102.2/ 85.4507 2021-Jan-27 00:00 174.41333 -19.17750 0.17589974621843 17.777 4.430 122.1599 /L 79.0/ 96.3782 2021-Jan-29 00:00 173.76648 -19.37880 0.17073231751647 17.670 4.403 124.3649 /L 55.3/ 99.8288 2021-Jan-31 00:00 173.00421 -19.53284 0.16561105223612 17.558 4.373 126.6476 /L 33.8/ 94.0400 2021-Feb-02 00:00 172.11861 -19.63287 0.16055844469343 17.444 4.341 129.0102 /L 26.7/ 79.3242 2021-Feb-04 00:00 171.10195 -19.67103 0.15559970998988 17.326 4.306 131.4534 /L 43.0/ 58.4687 2021-Feb-06 00:00 169.94734 -19.63840 0.15076312087651 17.206 4.270 133.9754 /L 67.4/ 35.8975 2021-Feb-08 00:00 168.64950 -19.52521 0.14607970420823 17.084 4.231 136.5700 /L 93.4/ 16.3756 2021-Feb-10 00:00 167.20551 -19.32120 0.14158239927857 16.960 4.189 139.2249 /L 118.6/ 3.8081 2021-Feb-12 00:00 165.61553 -19.01618 0.13730490891062 16.836 4.145 141.9186 /L 140.6/ 0.2152 2021-Feb-14 00:00 163.88319 -18.60053 0.13328055864353 16.712 4.099 144.6179 /L 151.5/ 5.3390 2021-Feb-16 00:00 162.01579 -18.06577 0.12954144090500 16.591 4.051 147.2729 /L 142.5/ 17.2870 2021-Feb-18 00:00 160.02435 -17.40508 0.12611784512459 16.475 4.004 149.8121 /L 123.1/ 33.6513 2021-Feb-20 00:00 157.92363 -16.61391 0.12303773238773 16.367 3.958 152.1364 /L 100.8/ 52.1906 2021-Feb-22 00:00 155.73191 -15.69064 0.12032606004839 16.272 3.918 154.1152 /L 77.4/ 70.7852 2021-Feb-24 00:00 153.47052 -14.63714 0.11800398673537 16.193 3.887 155.5911 /T 53.7/ 86.9580 2021-Feb-26 00:00 151.16303 -13.45910 0.11608819201653 16.137 3.868 156.4028 /T 33.3/ 97.5363 2021-Feb-28 00:00 148.83435 -12.16600 0.11459058725341 16.107 3.867 156.4274 /T 30.9/ 99.2361 2021-Mar-02 00:00 146.50987 -10.77085 0.11351839882305 16.105 3.883 155.6267 /T 51.4/ 90.4644 2021-Mar-04 00:00 144.21497 -9.28971 0.11287407369987 16.130 3.914 154.0616 /T 78.6/ 72.8856 2021-Mar-06 00:00 141.97440 -7.74123 0.11265447481903 16.177 3.957 151.8638 /T 106.5/ 50.8328 2021-Mar-08 00:00 139.81145 -6.14587 0.11284968725313 16.242 4.007 149.1899 /T 132.9/ 29.2547 2021-Mar-10 00:00 137.74680 -4.52486 0.11344226861062 16.320 4.061 146.1869 /T 153.1/ 12.2068 2021-Mar-12 00:00 135.79758 -2.89893 0.11440739012451 16.410 4.117 142.9774 /T 151.6/ 2.2907 2021-Mar-14 00:00 133.97666 -1.28707 0.11571382017783 16.507 4.172 139.6567 /T 131.6/ 0.5010 2021-Mar-16 00:00 132.29238 0.29443 0.11732550083598 16.611 4.225 136.2961 /T 108.0/ 6.3649 2021-Mar-18 00:00 130.74877 1.83253 0.11920338035725 16.718 4.276 132.9466 /T 84.0/ 18.4440 2021-Mar-20 00:00 129.34601 3.31759 0.12130715258146 16.827 4.325 129.6438 /T 60.0/ 34.9318 2021-Mar-22 00:00 128.08111 4.74316 0.12359669133753 16.938 4.371 126.4108 /T 36.5/ 53.9226 2021-Mar-24 00:00 126.94854 6.10565 0.12603318198138 17.049 4.415 123.2617 /T 17.6/ 73.1709 2021-Mar-26 00:00 125.94092 7.40381 0.12858009887279 17.159 4.457 120.2035 /T 27.0/ 89.5453 2021-Mar-28 00:00 125.04958 8.63832 0.13120414391004 17.269 4.496 117.2381 /T 53.5/ 98.9330 2021-Mar-30 00:00 124.26539 9.81121 0.13387594280944 17.377 4.534 114.3639 /T 83.0/ 97.7255 2021-Apr-01 00:00 123.57950 10.92548 0.13656990141778 17.483 4.570 111.5776 /T 113.0/ 85.4950 2021-Apr-03 00:00 122.98372 11.98455 0.13926298888441 17.588 4.604 108.8747 /T 141.7/ 65.7798 2021-Apr-05 00:00 122.47038 12.99200 0.14193330759209 17.691 4.637 106.2507 /T 166.3/ 43.7812 2021-Apr-07 00:00 122.03202 13.95150 0.14455942086685 17.792 4.669 103.7004 /T 159.2/ 23.9357 2021-Apr-09 00:00 121.66112 14.86677 0.14712044090085 17.890 4.701 101.2179 /T 135.0/ 9.2113 2021-Apr-11 00:00 121.34995 15.74161 0.14959641376222 17.987 4.731 98.7966 /T 110.6/ 1.3000 2021-Apr-13 00:00 121.09050 16.57989 0.15196873689972 18.082 4.762 96.4297 /T 86.4/ 0.8149 2021-Apr-15 00:00 120.87449 17.38554 0.15422054607425 18.176 4.792 94.1095 /T 62.6/ 7.4277 2021-Apr-17 00:00 120.69336 18.16251 0.15633704526832 18.268 4.822 91.8282 /T 38.8/ 20.1092 2021-Apr-19 00:00 120.53835 18.91471 0.15830576331599 18.359 4.852 89.5777 /T 15.0/ 37.3923 NEOWISE detection? 2021-Apr-21 00:00 120.40046 19.64600 0.16011677989067 18.450 4.883 87.3498 /T 12.2/ 57.3773 2021-Apr-23 00:00 120.27053 20.36016 0.16176302384399 18.540 4.915 85.1359 /T 38.3/ 77.3150 2021-Apr-25 00:00 120.13932 21.06081 0.16324070262299 18.631 4.949 82.9276 /T 66.9/ 93.1009 2021-Apr-27 00:00 119.99773 21.75139 0.16454965199588 18.723 4.984 80.7165 /T 97.1/ 99.8950 2021-Apr-29 00:00 119.83713 22.43511 0.16569302909901 18.817 5.021 78.4948 /T 127.8/ 94.8470

Setups



Due the 30.56 h rotation period and a diameter of roughly 0.34 km, we are expecting a bandwidth
of about 0.8 Hz.  The shape is elongated so the bandwidth could vary by about a factor of two
the asteroid spins.  Due to the slow rotation period and relatively short duration of some tracks, 
bandwidth variations during many tracks will be small. 

CW setup:
---------------------------------------------------------------------------
TX polarization           RCP
RCV polarization          LCP & RCP
Frequency hops:           no hopping
Bandwidth:               5000 Hz 
TXoffset                 +500 Hz
FFT                     10000 for 0.5 Hz resolution 

Ranging setups:
---------------------------------------------------------------------------
10-usec
baud             10 usec
code            127
PRP            1270 usec
ncoh              8
bandwidth        98 Hz   
FFT             128
resolution        0.77 Hz
TXoffset        +20 Hz  (echo in column 90)
---------------------------------------------------------------------------
11-usec 
baud             11 usec
code            127
PRP            1397 usec
ncoh              8
bandwidth        89 Hz   
FFT             128
resolution        0.7 Hz
TXoffset        +20 Hz  (echo in column 93) 
-------------------------------------------------------------------------
1-usec 
baud              1 usec
code            255
ncoh             16 
bandwidth       245 Hz   
FFT             256 
resolution        0.96 Hz
TXoffset        +20 Hz  (echo in column 149)
---------------------------------------------------------------------

Instructions

NOTE: Data should be moved to the appropriate subdirectories in aardvark:/export/data0/apophis/raw/

POINTING:

  OSOD and predicts are on aardvark:
/export/data3/osod/ops/a99942/EPH.OUT.s???
/export/data3/osod/ops/a99942/PRDX.OUT.14f-14-14.s???
/export/data3/osod/ops/a99942/PRDX.OUT.14v-14-14.s???
/export/data3/osod/ops/a99942/PUNCH.OUT.14f-14-14.s???
/export/data3/osod/ops/a99942/PUNCH.OUT.14v-14-14.s???


POINTING  

...Not available yet...

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

(99942) APOPHIS GOLDSTONE MASTERLOG

Receive Setup code ncoh FFT runs start -stop OSOD offset
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/Apophis/apophis.2021.goldstone.planning.html

Asteroid Radar Astronomy
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