2011 BT15 Goldstone Radar Observations Planning


Background


2011 BT15 was discovered by Pan-STARRS (Haleakala, HI) on January 24, 2011.
It has an absolute magnitude of 21.7, suggesting a diameter within a factor of two
of 140 meters, but nothing else is known about its physical properties.
This object will be too faint for optical observations until early January of 2014,
when it should reach visual magnitude 17 and be a good target for lightcurves and BVRI colors.

2011 BT15 makes regular close approaches within 0.1 AU of both Earth and Mars.  The closest
approach during this apparition will occur at 0.032 AU (~ 12.5 lunar distances) on December 28,
when this asteroid should be a moderately strong radar target at Goldstone.  At the time of the
closest approach, it will be too far south for Arecibo to track, but after Jan. 4 it will move
north into Arecibo's declination range and become a strong imaging target.

This object is on NASA's "NHATS" list of potential human mission targets.  As a result, physical
observations are particularly important.

2011 BT15 has been classified as a "Potentially Hazardous Asteroid" (PHA) by the IAU's Minor Planet Center.
Orbital and Physical Characteristics  
 orbit type               Apollo
 semimajor axis           1.297 AU
 eccentricity             0.304
 inclination              1.7 deg
 perihelion distance      0.903 AU
 aphelion distance        1.691 AU
 absolute magnitude (H)   21.7
 diameter                 140 m (+/- a factor of two)
 rotation period          unknown
 pole direction           unknown
 lightcurve amplitude     unknown
 spectral class           unknown


Future Close-approaches:

          Date (CT)       Body   CA Dist  MinDist  MaxDist   Vrel  TCA3Sg  Nsigs  P_i/p
  ----------------------  -----  -------  -------  -------  ------ ------ ------ -------
  A.D. 2013 Dec 28.64804  Earth  .032226  .032223  .032229   6.000   1.14 34564. .000000
  A.D. 2016 Sep 15.39071  Earth  .050851  .050849  .050853   8.171   0.43 80852. .000000
  A.D. 2034 Dec 30.43280  Mars   .088653  .088645  .088661   7.598   0.38 40270. .000000
  A.D. 2038 Dec 28.62563  Earth  .034507  .034495  .034518   5.948   5.23 10605. .000000
  A.D. 2056 Feb 14.63544  Mars   .038894  .038876  .038912   6.197   3.28 2.86E5 .000000
  A.D. 2060 Dec 25.61175  Earth  .043404  .043325  .043483   5.754  41.06 8778.7 .000000
  A.D. 2069 Apr 03.87949  Mars   .074414  .074377  .074450   5.012  13.56 2.22E5 .000000
  A.D. 2082 Sep 24.04659  Earth  .031911  .031790  .032034   6.427  74.75 78747. .000000
  A.D. 2102 Jan 07.68721  Earth  .009398  .007487  .011289   7.230 385.89 3268.4 .000000
  A.D. 2104 Oct 26.62162  Earth  .080565  .071032  .093075   5.559 26244. 2.18E5 .000000

  NOTE: post-epoch CA list was truncated due to Earth TCA3Sg exceeding the set limit.


Last update: 2013 Dec 16

Discovery MPEC

M.P.E.C. 2011-B43                                Issued 2011 Jan. 27, 05:20 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.

             Prepared using the Tamkin Foundation Computer Network

                              MPC@CFA.HARVARD.EDU
       URL http://www.minorplanetcenter.org/iau/mpc.html  ISSN 1523-6714

                                   2011 BT15

Observations:
     K11B15T* C2011 01 24.28933 01 49 25.905+11 35 47.92         22.1 wLEB043F51
     K11B15T  C2011 01 24.29437 01 49 27.985+11 36 01.94         21.8 wLEB043F51
     K11B15T  C2011 01 24.29932 01 49 29.981+11 36 15.38         22.2 wLEB043F51
     K11B15T %C2011 01 25.31754 01 56 37.39 +12 23 07.7          21.0 RoEB043F65
     K11B15T tC2011 01 26.11773 02 02 16.53 +12 59 26.4          21.1 VoEB043291
     K11B15T tC2011 01 26.12153 02 02 18.08 +12 59 37.4          21.9 VoEB043291
     K11B15T tC2011 01 26.14194 02 02 26.61 +13 00 32.0          22.1 VoEB043291
     K11B15T tC2011 01 26.14966 02 02 29.80 +13 00 52.8                oEB043291
     K11B15T tC2011 01 27.17027 02 09 43.77 +13 46 36.0          21.5 VoEB043291
     K11B15T tC2011 01 27.17399 02 09 45.25 +13 46 45.7          21.5 VoEB043291

Observer details:
291 LPL/Spacewatch II.  Observer T. H. Bressi.  1.8-m f/2.7 reflector + CCD.
F51 Pan-STARRS 1, Haleakala.  Observers N. Primak, A. Schultz, S. Watters,
    J. Thiel, T. Goggia.  Measurer PS1 Science Consortium.  1.8-m
    Ritchey-Chretien + CCD.
F65 Haleakala-Faulkes Telescope North.  Observer T. Lister.  2.0-m f/10
    Ritchey-Chretien + CCD.

Orbital elements:
2011 BT15                                           PHA, Earth MOID = 0.0013 AU
Epoch 2011 Feb. 8.0 TT = JDT 2455600.5                  MPC
M  36.48821              (2000.0)            P               Q
n   0.63120667     Peri.  309.74665     +0.57676209     -0.81638539
a   1.3459275      Node   105.00619     +0.75848382     +0.52182954
e   0.3283427      Incl.    1.74022     +0.30339377     +0.24740417
P   1.56           H   21.9           G   0.15           U   9
Residuals in seconds of arc
110124 F51  0.0   0.0     110126 291  0.2-  0.5-    110127 291  0.5+  0.2+
110124 F51  0.3+  0.1+    110126 291  0.5-  0.3+    110127 291  0.6-  0.1+
110124 F51  0.2-  0.0     110126 291  0.7+  0.1-
110125 F65  0.6-  0.3+    110126 291  0.5+  0.0

Ephemeris:
2011 BT15                a,e,i = 1.35, 0.33, 2                   q = 0.9040
Date    TT    R. A. (2000) Decl.     Delta      r     Elong.  Phase     V
2010 12 28    23 08 25.8 -08 00 03   0.3454  0.9186    69.1    90.4    22.6
...
2011 01 12    00 29 16.8 +01 58 50   0.2938  0.9571    76.2    86.4    22.2
...
2011 01 20    01 20 08.4 +08 13 51   0.2797  0.9857    82.2    81.5    22.0
...
2011 01 26    02 01 27.1 +12 54 16   0.2773  1.0099    87.2    76.8    21.8
2011 01 27    02 08 32.1 +13 39 11   0.2777  1.0141    88.1    76.0    21.8
2011 01 28    02 15 39.5 +14 23 18   0.2783  1.0184    89.0    75.2    21.8
...
2011 02 03    02 58 53.2 +18 26 02   0.2864  1.0452    94.0    70.2    21.7
...
2011 02 11    03 55 43.7 +22 32 53   0.3093  1.0831    99.8    63.9    21.8
...
2011 02 26    05 29 48.9 +26 08 42   0.3844  1.1583   106.3    55.1    22.1

Sonia Keys                   (C) Copyright 2011 MPC           M.P.E.C. 2011-B43

SNR Calculation

2011 BT15
D = 0.14 km     
P = 2.1 h       (assume rapid rotation; this places a conservative lower bound on the SNRs) 
OC albedo = 0.1 (a relatively conservative lower bound)
                      UTC                                       SNR/       SNR/
w  DOY  start date   window        RA, dec  dist    runs        day        run
52 357 2013 Dec 23  16:30-19:20   244, -31  0.036    141         34         3
52 358 2013 Dec 24  15:45-19:15   239, -30  0.035    174         44         3
52 359 2013 Dec 25  15:05-19:05   233, -28  0.034    209         56         4
52 360 2013 Dec 26  14:20-18:55   227, -26  0.033    245         69         5
52 361 2013 Dec 27  13:35-18:45   221, -23  0.032    279         80         5
52 362 2013 Dec 28  12:50-18:30   215, -21  0.032    310         89         5  Scheduled
52 363 2013 Dec 29  12:10-18:20   209, -18  0.032    336         93         6 

01 364 2013 Dec 30  11:30-18:10   204, -15  0.033    355         93         5
01 365 2013 Dec 31  10:55-18:00   199, -12  0.034    368         89         5
01 001 2014 Jan 01  10:20-17:50   195,  -9  0.035    375         82         5
01 002 2014 Jan 02  09:50-17:40   191,  -6  0.036    377         73         4
01 003 2014 Jan 03  09:20-17:30   187,  -4  0.038    375         63         4
01 004 2014 Jan 04  08:55-17:20   183,  -1  0.040    369         53         3
01 005 2014 Jan 05  08:30-17:10   180,  +1  0.042    361         45         3

Goldstone SNRs assume Ptx = 450 kW 


Arecibo SNRs
                      UTC                                      SNR/       SNR/
        start date    window       RA, dec   dist    runs      date       run
       2014 Jan 05  08:56-10:07   181,  +1  0.042     52        760       110
       2014 Jan 06  08:28-10:04   178,  +3  0.044     67        820       110
       2014 Jan 07  08:05-09:58   175,  +4  0.046     76        780        99
       2014 Jan 08  07:46-09:50   173,  +6  0.049     78        680        83
       2014 Jan 09  07:28-09:42   171,  +7  0.051     81        580        69  Scheduled
       2014 Jan 10  07:13-09:34   169,  +9  0.054     80        490        58  Scheduled
       2014 Jan 11  06:59-09:25   167, +10  0.056     78        410        49
       2014 Jan 12  06:46-09:16   165, +11  0.059     76        340        41
       2014 Jan 13  06:34-09:08   164, +12  0.062     74        290        35
       2014 Jan 14  06:23-08:59   162, +13  0.065     73        240        30
       2014 Jan 15  06:13-08:51   161, +14  0.068     71        200        25
       2014 Jan 16  06:03-08:43   159, +14  0.071     68        170        22
       2014 Jan 17  05:53-08:35   158, +15  0.074     65        140        19
       2014 Jan 18  05:44-08:27   157, +16  0.078     63        120        16
       2014 Jan 19  05:36-08:19   156, +16  0.081     61        100        14
       2014 Jan 20  05:27-08:11   155, +17  0.084     59         89        12
       2014 Jan 21  05:19-08:04   154, +17  0.087     57         77        11
       2014 Jan 22  05:11-07:56   153, +18  0.091     52         64         9
       2014 Jan 23  05:04-07:49   152, +18  0.094     50         55         8
       2014 Jan 24  04:56-07:42   151, +18  0.098     48         47         7
       2014 Jan 25  04:49-07:35   151, +19  0.102     46         41         6

Arecibo SNRs assume Ptx = 900 kw.  Current transmitter power is closer to 600 kW.
This object will be an excellent imaging target at Arecibo, where it should be 
possible to obtain images with resolutions as fine as 7.5 meters/pixel.

Track Assignments


 DAY START BOT  EOT  END FACILITY USER   ACTIVITY      
362 1120 1250 1625 1655  DSS-14  GSSR   AST 2011 BT1T5 

Goldstone tracks:

         UT         UT            PST                       Duration   Round-trip   SNR/  
 DOY     Date       TX Window     TX Window                   hh:mm    time (sec)   Run 
 ---     ----       ---------     ---------                 ---------  ---------    ----
 262     Dec 28     1255-1625     0455-0825 Dec 28             3:30     32            5

Transmit authorization starts at the end of precal.



Arecibo tracks:

   9     Jan 09     0728-0942     2328-0142 Jan  8- 9          2:14     51           69
  10     Jan 10     0713-0934     2313-0134 Jan  9-10          2:21     54           58



Uncertainties

From Horizons, 2013 Dec 16, Solution 30, # obs: 101 (2007-2013)

 Date__(UT)__HR:MN     R.A._(J2000.0)_DEC.            delta POS_3sigma  DOP_S_3sig  DOP_X_3sig  RT_delay_3sig
 2013-Dec-10 00:00 *m  285.66620 -32.75903 0.07612293791871     10.000        3.39       12.34       0.001867
 2013-Dec-11 00:00 *m  284.36093 -32.98268 0.07255877633210     10.659        3.70       13.45       0.001755
 2013-Dec-12 00:00 *m  282.88501 -33.20627 0.06906061837145     11.371        4.04       14.68       0.001633
 2013-Dec-13 00:00 *m  281.21732 -33.42505 0.06563530774089     12.141        4.42       16.05       0.001502
 2013-Dec-14 00:00 *m  279.33402 -33.63244 0.06229058026066     12.971        4.83       17.57       0.001363
 2013-Dec-15 00:00 *m  277.20835 -33.81951 0.05903525575322     13.862        5.30       19.25       0.001215
 2013-Dec-16 00:00 *m  274.81071 -33.97424 0.05587947215990     14.810        5.81       21.10       0.001063
 2013-Dec-17 00:00 *   272.10906 -34.08061 0.05283496349368     15.811        6.37       23.13       0.000914
 2013-Dec-18 00:00 *   269.06984 -34.11761 0.04991537845702     16.850        6.97       25.34       0.000784
 2013-Dec-19 00:00 *   265.65980 -34.05813 0.04713662667456     17.907        7.62       27.70       0.000705
 2013-Dec-20 00:00 *   261.84898 -33.86803 0.04451722185527     18.946        8.30       30.15       0.000720
 2013-Dec-21 00:00 *   257.61518 -33.50569 0.04207856300410     19.919        8.97       32.62       0.000849
 2013-Dec-22 00:00 *   252.95001 -32.92272 0.03984505450387     20.755        9.61       34.93       0.001072
 2013-Dec-23 00:00 *   247.86596 -32.06668 0.03784391691051     21.363       10.15       36.89       0.001359
 2013-Dec-24 00:00 *   242.40325 -30.88648 0.03610449731083     21.638       10.52       38.22       0.001687
 2013-Dec-25 00:00 *   236.63389 -29.34102 0.03465688425890     21.468       10.62       38.61       0.002039
 2013-Dec-26 00:00 *   230.66044 -27.40990 0.03352971870298     20.759       10.39       37.76       0.002399
 2013-Dec-27 00:00 *   224.60767 -25.10347 0.03274731335521     19.463        9.77       35.52       0.002751
 2013-Dec-28 00:00 *   218.60810 -22.46821 0.03232652883315     17.605        8.78       31.90       0.003078
 2013-Dec-29 00:00 *   212.78526 -19.58381 0.03227416428322     15.297        7.47       27.17       0.003365
 2013-Dec-30 00:00 *   207.23967 -16.55172 0.03258567295259     12.724        5.99       21.79       0.003603
 2013-Dec-31 00:00 *   202.04121 -13.47868 0.03324566584401     10.123        4.48       16.30       0.003785
 2014-Jan-01 00:00 *m  197.22849 -10.46089 0.03423004844148      7.752        3.09       11.24       0.003912
 2014-Jan-02 00:00 *m  192.81326  -7.57357 0.03550910169866      5.892        1.95        7.09       0.003988
 2014-Jan-03 00:00 *m  188.78729  -4.86717 0.03705065874660      4.831        1.26        4.57       0.004019
 2014-Jan-04 00:00 *m  185.12926  -2.36916 0.03882274242737      4.670        1.22        4.43       0.004014
 2014-Jan-05 00:00 *m  181.81054  -0.08866 0.04079539317626      5.119        1.56        5.67       0.003979
 2014-Jan-06 00:00 *m  178.79943   1.97809 0.04294171351407      5.785        1.93        7.00       0.003922
 2014-Jan-07 00:00 *m  176.06394   3.84288 0.04523830234934      6.442        2.22        8.08       0.003849
 2014-Jan-08 00:00 *m  173.57350   5.52178 0.04766527925205      7.005        2.44        8.87       0.003764
 2014-Jan-09 00:00 *m  171.29988   7.03253 0.05020606704022      7.452        2.59        9.42       0.003671
 2014-Jan-10 00:00 *m  169.21761   8.39287 0.05284705412361      7.788        2.69        9.78       0.003572


Apparent Magnitudes, Solar Elongations, Lunar Elongations, and Lunar Illumination:

 Date__(UT)__HR:MN     R.A._(J2000.0)_DEC.            delta  APmag    S-O-T /r  T-O-M/Illu%
 2013-Dec-15 00:00     277.23916 -33.78741 0.05904043285921    27.  16.7642 /T  138.6/ 94.7
 2013-Dec-16 00:00     274.84491 -33.94123 0.05588323922945    28.  14.5789 /T  151.4/ 98.2
 2013-Dec-17 00:00     272.14697 -34.04681 0.05283716426623    29.  12.5924 /T  162.0/ 99.8
 2013-Dec-18 00:00     269.11175 -34.08318 0.04991584042280    30.  11.1203 /T  164.7/ 99.5
 2013-Dec-19 00:00     265.70595 -34.02330 0.04713516170373    31.  10.6600 /L  156.2/ 97.5
 2013-Dec-20 00:00     261.89948 -33.83308 0.04451362861180    30.  11.6545 /L  143.4/ 93.9
 2013-Dec-21 00:00     257.66996 -33.47095 0.04207263211521    28.  14.1187 /L  129.0/ 88.6
 2013-Dec-22 00:00     253.00872 -32.88859 0.03983657765609    26.  17.7528 /L  113.9/ 82.0
 2013-Dec-23 00:00     247.92794 -32.03350 0.03783270101181    24.  22.2727 /L   98.0/ 74.2
 2013-Dec-24 00:00     242.46743 -30.85453 0.03609038429135    23.  27.4968 /L   81.5/ 65.4
 2013-Dec-25 00:00     236.69885 -29.31044 0.03463977564273    22.  33.3051 /L   64.3/ 55.9
 2013-Dec-26 00:00     230.72451 -27.38056 0.03350960167653    21.  39.5946 /L   46.4/ 45.8
 2013-Dec-27 00:00     224.66913 -25.07503 0.03272428228448    20.  46.2547 /L   28.1/ 35.6
 2013-Dec-28 00:00     218.66540 -22.44011 0.03230079466389    19.  53.1570 /L   10.5/ 25.7
 2013-Dec-29 00:00     212.83718 -19.55545 0.03224604595622  18.88  60.1594 /L   14.0/ 16.6
 2013-Dec-30 00:00     207.28546 -16.52258 0.03255557038018  18.44  67.1177 /L   33.2/  8.9
 2013-Dec-31 00:00     202.08058 -13.44841 0.03321402073889  18.09  73.9015 /L   53.5/  3.4
 2014-Jan-01 00:00     197.26151 -10.42940 0.03419730334018  17.84  80.4063 /L   74.0/  0.5
 2014-Jan-02 00:00     192.84027  -7.54096 0.03547566661380  17.65  86.5607 /L   94.3/  0.6
 2014-Jan-03 00:00     188.80880  -4.83370 0.03701689034004  17.51  92.3258 /L  114.2/  3.8
 2014-Jan-04 00:00     185.14585  -2.33515 0.03878893565384  17.42  97.6903 /L  133.5/  9.7
 2014-Jan-05 00:00     181.82281  -0.05445 0.04076178231838  17.36 102.6631 /L  151.9/ 17.8
 2014-Jan-06 00:00     178.80793   2.01219 0.04290847875916  17.32 107.2660 /L  169.1/ 27.5
 2014-Jan-07 00:00     176.06919   3.87662 0.04520557869413  17.31 111.5285 /L  171.3/ 37.9
 2014-Jan-08 00:00     173.57595   5.55495 0.04763316562524  17.31 115.4828 /L  156.0/ 48.5
 2014-Jan-09 00:00     171.29995   7.06497 0.05017463451335  17.32 119.1611 /L  140.6/ 58.9
 2014-Jan-10 00:00     169.21564   8.42447 0.05281635276969  17.34 122.5942 /L  125.6/ 68.6

Setups



We don't know anything about the spin state of 2011 BT15, so 
we will start with a relatively coarse Doppler resolution in order to quickly see the echo.

CW setup:
---------------------------------------------------------------------------
TX polarization           RCP
RCV polarization          LCP & RCP
Frequency hops:           no hops (+0.5 kHz offset)                  
Bandwidth:                4000 Hz 
Sampling interval:        2500 x 0.1 usec 
PFS FFT:             :    4000 for 1.0 Hz res 

Ranging setups:
---------------------------------------------------------------------------
10-usec
baud             10 usec
code            127
PRP            1270 usec
FFT             128   
ncoh              1 
bandwidth       787 Hz   
resolution      6.15 Hz
TXOFF          +100Hz  (echo in bin 64+16=80)
---------------------------------------------------------------------------
11-usec 
baud             11 usec
code            127
PRP            1397 usec
FFT             128  
ncoh              1 
bandwidth       716 Hz   
resolution      5.6 Hz
TXOFF          +100 Hz  (echo in bin 64+18=82) 
-------------------------------------------------------------------------
1-usec 
baud            1 usec
code            127
FFT             512
ncoh             128
bandwidth        61.3 Hz   
resolution       0.12 Hz
TXOFF           +8 Hz -> echo would be centered at 256 + 67=323
-------------------------------------------------------------------------------
0.25-usec ranging 
baud            0.25 usec
code            255
FFT             128
ncoh             16
bandwidth       980  Hz     
resolution       7.7 Hz
TXOFF          +80 Hz -> echo would be centered at 64 + 10 = 74
-------------------------------------------------------------------------------
0.125-usec ranging 
baud            0.125 usec
code            255
FFT             128
ncoh             32
bandwidth       980  Hz     
resolution       7.7 Hz
TXOFF          +80 Hz -> echo would be centered at 64 + 10 = 74

_____________________________________________________________________
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/data0/2011BT15/raw/

2013 NJ POINTING:

  OSOD and predicts are aardvark:

Monostatic with the new waveform generator:
/export/data3/osod/ops/2011bt15/PRDX.OUT.14v-14-14.s??
                              /PUNCH.OUT.14v-14-14.s??
                              /EPH.OUT.s??

POINTING 
                                                       TX Offsets    
Date (UTC)   DOY  hhmmss    RA        Dec      Macro   LHA     Dec  RTT    OSOD

... to be added later ...

Transmit offsets are given in millidegrees.  


PRDX.OUT.14f-14-14.s?? ... to be added later ...

2011 BT15GOLDSTONE MASTERLOG

============================================================================== Receive TX Setup hops dwell code ncoh FFT runs start -stop OSOD offset Poln Notes ------------------------------------------------------------------------------
Dr. Lance A. M. Benner | PHONE: (818) 354-7412 Mail Stop 183-610 | 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 http://echo.jpl.nasa.gov/asteroids/2011BT15/2011BT15_planning.html

Asteroid Radar Astronomy
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