Detections

Detection Statistics:

 This file = ../../Output/All_Obs_84J-21A/Tally_SpW_Obs_84J-21A.txt

 Started at 01:40:27 Elapsed time = 17.043 hrs.

 Output of program SITESORT on 2021 03 01 01:40:27

 Operating on file: ../../Input/AllObs_210127.txt                                                   

 Input data from the IAU Minor Planet Center.

 Date range analyzed =  1984.3313 to 2021.0411

 Site code (COD) groupings:

 SW291 = Spacewatch 1.8-m on Kitt Peak.

 SW691 = Spacewatch 0.9-m on Kitt Peak.

 SW695 = Spacewatch w Bok 2.3-m & Mayall 4-m.

 BokV00= 90Prime on Bok 2.3-m with CSS.

 

 NREC = # of obs. records by observing site.

 NRNEO= # of NEO obs. records by observatory.

 NR22N= # of H<=22 NEO records by site.

 NR18N= # of H<=17.75 NEO records by observatory.

 NDNEO= # of different NEOs by observatory.

 ND22N= # of different H<=22 NEOs by site.

 ND18N= # of different H<=17.75 NEOs by site.

 NRPHA= # of PHA obs. records by observatory.

 NR18P= # of H<=17.75 PHA records by observatory.

 NDPHA= # of different PHAs by observatory.

 ND18P= # of different H<=17.75 PHAs by site.

 NRPHAV = # of records of PHAs w/ mag .GE. VLIM

 NCOMREC = # of records on comets.

 

 VLIM =  22.50 mag.

 

  Site        NREC   NRNEO   NR22N  NR18N NDNEO ND22N ND18N  NRPHA NR18P NDPHA ND18P NRPHAV  NCOMREC

 

 SW_291     900536   81518   49451   2850 10589  5412   384   19926   798  1568    85   933    2240

 SW_691   13911786   48078   35727   8544  6056  3903   603   10069  1828   968   109    50    7831

 SW_695       7900    6564    4193    366  1346   780    47    2251    67   419    11   673     105

 BokV00     133475     567     291     83   128    67    20      99    39    21     9     0      29

 

 FIRST= Date of first observation counted.

 LAST = Date of last observation counted.

 

 AVDT_NEO1 = Av. deltaT for NEOs w/ H .LE. 17.75

 AVDT_NEO2 = Av. deltaT for NEOs w/ H .LE. 22.0

 AVDT_NEO3 = Av. deltaT for NEOs w/ H .GT. 22.0

 AVDT_PHA1 = Av. deltaT for PHAs w/ H .LE. 17.75

 AVDT_PHA2 = Av. deltaT for PHAs w/ H .GT. 17.75

 DTMXNEO1  = Max deltaT for NEOs w/ H .LE. 17.75

 DTMXNEO2  = Max deltaT for NEOs w/ H .LE. 22.0

 DTMXNEO3  = Max deltaT for NEOs w/ H .GT. 22.0

 DTMXPHA1  = Max deltaT for PHAs w/ H .LE. 17.75

 DTMXPHA2  = Max deltaT for PHAs w/ H .GT. 17.75

 

 

  Site      FIRST     LAST   AVDT_NEO1  AVDT_NEO2  AVDT_NEO3  AVDT_PHA1  AVDT_PHA2   DTMXNEO1   DTMXNEO2   DTMXNEO3   DTMXPHA1   DTMXPHA2

 

 SW_291 1992.8829 2021.0371     239.84     133.48      16.14     265.68     130.01    5574.14    5851.98    4019.94    5574.14    5208.09

 SW_691 1984.3346 2021.0371     168.97     106.05      10.37     135.99      73.07   15715.86   17264.95    4273.40    5224.62    4227.72

 SW_695 2010.2308 2021.0097     304.06     244.74      77.90     302.70     261.02    1677.22    5206.47    5861.19    1373.17    5206.47

 BokV00 2019.8796 2020.9542     136.54     187.59       5.49      93.91     172.92     671.90    3824.15      39.44     344.44    1002.72

 

  Histograms vs. deltaT

 

                         dT<3hr   3-9hr  9hr-1d    1-3d   3d-9d   9-30d  30-90d  90d-1y   1-3yr   3-9yr   >9 yr

 

 SW_291 NEO .LE. 17.75       46      41     132     148      89     103      96      64     133      64       3

 SW_291 NEO .LE. 22.0      1018     830    2702    3085    2315    2427     799     521     727     616      45

 SW_291 NEO .GT. 22.0      1175     885    2391    2483    1593    1062      72      67      34      44       1

 SW_291 PHA .LE. 17.75        6       7      31      48      24      28      42      15      37      21       1

 SW_291 PHA .GT. 17.75      325     334    1094    1334    1019    1038     360     271     286     236      21

 SW_691 NEO .LE. 17.75      131     108     368     542     675     421     120     108     253      81      16

 SW_691 NEO .LE. 22.0       611     433    1708    1931    1720    1097     223     152     300     209      47

 SW_691 NEO .GT. 22.0       499     379     946     949     514     213      12       9      10       8       1

 SW_691 PHA .LE. 17.75       31      22      76     107     156      92      23      33      61      15       2

 SW_691 PHA .GT. 17.75      197     141     545     560     534     342      64      62      78      54       5

 SW_695 NEO .LE. 17.75        0       0      15       9      10       9       5      12      14       9       0

 SW_695 NEO .LE. 22.0        22      19     171     149     164     234     108      72      93      87       8

 SW_695 NEO .GT. 22.0        39      21     116     138     169     180      35      17       6      15       3

 SW_695 PHA .LE. 17.75        0       0       3       1       1       1       0       4       3       1       0

 SW_695 PHA .GT. 17.75       12      13      84      70      99     154      66      42      56      49       7

 BokV00 NEO .LE. 17.75        0       1       2       3       2       4       0       3       3       0       0

 BokV00 NEO .LE. 22.0         1       3       6       6       5      16       2       3       5       0       1

 BokV00 NEO .GT. 22.0        11       2       4       7       5       7       1       0       0       0       0

 BokV00 PHA .LE. 17.75        0       1       1       1       1       1       0       3       0       0       0

 BokV00 PHA .GT. 17.75        0       1       2       2       1       4       1       0       3       0       0

 

 FIRST= Date of first observation counted.

 LAST = Date of last observation counted.

 Arc extensions are in fractions of the original arc.

 

 AVAE_NEO1 = Av. arc extension for NEOs w/ H .LE. 17.75

 AVAE_NEO2 = Av. arc extension for NEOs w/ H .LE. 22.0

 AVAE_NEO3 = Av. arc extension for NEOs w/ H .GT. 22.0

 AVAE_PHA1 = Av. arc extension for PHAs w/ H .LE. 17.75

 AVAE_PHA2 = Av. arc extension for PHAs w/ H .GT. 17.75

 AEMXNEO1  = Max arc extension for NEOs w/ H .LE. 17.75

 AEMXNEO2  = Max arc extension for NEOs w/ H .LE. 22.0

 AEMXNEO3  = Max arc extension for NEOs w/ H .GT. 22.0

 AEMXPHA1  = Max arc extension for PHAs w/ H .LE. 17.75

 AEMXPHA2  = Max arc extension for PHAs w/ H .GT. 17.75

 

  Site      FIRST     LAST   AVAE_NEO1  AVAE_NEO2  AVAE_NEO3  AVAE_PHA1  AVAE_PHA2   AEMXNEO1   AEMXNEO2   AEMXNEO3   AEMXPHA1   AEMXPHA2

 

 SW_291 1992.8829 2021.0371      17.72      24.31       2.46      59.33       1.49   15269.48  334331.63    1266.64   15269.48    2108.70

 SW_691 1984.3346 2021.0371     957.74     986.96      12.66     217.81     238.78  649074.95  762631.00   17746.55   48742.15  174076.03

 SW_695 2010.2308 2021.0097       0.27       1.77       3.40       0.55       1.06       6.74     644.41     797.09       3.36      49.40

 BokV00 2019.8796 2020.9542       0.02      19.90       4.41       0.01       0.09       0.10     844.82      75.25       0.02       0.80

 

  Histograms of Fractional Arc Extensions

 

                          <0.2    .2-.5  0.5-1x    1-3x   3-10x  10-30x  30-100x 100-300 300-1d3 1d3-3d3 >3000x

 

 SW_291 NEO .LE. 17.75      626      94      65      70      40      19       4       0       0       0       1

 SW_291 NEO .LE. 22.0      9056    2226    1482    1109     652     373     146      33       6       1       1

 SW_291 NEO .GT. 22.0      4266    1675    1296    1375     695     345     144       9       1       1       0

 SW_291 PHA .LE. 17.75      186      28      20      13       8       4       0       0       0       0       1

 SW_291 PHA .GT. 17.75     4329     887     467     300     205      86      30      13       0       1       0

 SW_691 NEO .LE. 17.75     2568      93      54      32      14      19      12       3       7       3      18

 SW_691 NEO .LE. 22.0      6697     659     379     256      94     116      77      53      27      13      60

 SW_691 NEO .GT. 22.0      2231     524     323     221     108      72      37      13       4       3       4

 SW_691 PHA .LE. 17.75      566      21       9       7       4       2       2       1       1       1       4

 SW_691 PHA .GT. 17.75     2216     144      81      48      25      27      12      17       3       2       7

 SW_695 NEO .LE. 17.75       59      13       7       2       2       0       0       0       0       0       0

 SW_695 NEO .LE. 22.0       687     123     101     116      78      14       7       0       1       0       0

 SW_695 NEO .GT. 22.0       332     120     105     124      44       8       3       1       2       0       0

 SW_695 PHA .LE. 17.75        8       1       3       1       1       0       0       0       0       0       0

 SW_695 PHA .GT. 17.75      414      66      48      67      45       9       3       0       0       0       0

 BokV00 NEO .LE. 17.75       18       0       0       0       0       0       0       0       0       0       0

 BokV00 NEO .LE. 22.0        38       4       2       1       1       0       0       1       1       0       0

 BokV00 NEO .GT. 22.0        20       1       5       3       5       1       2       0       0       0       0

 BokV00 PHA .LE. 17.75        8       0       0       0       0       0       0       0       0       0       0

 BokV00 PHA .GT. 17.75       12       1       1       0       0       0       0       0       0       0       0

 

Discoveries:  See Minor Planet Discovery Sites and Summary of PHA and NEA Discoveries by Discoverers which provide the numbers of discoveries by the various observatories in total and year-by-year.  Spacewatch's observatory codes used by the Minor Planet Center are"291" and "691".  Discoveries of NEOs by Spacewatch peaked in the mid-1990s, before shifting priority to following up already-known NEOs to prevent them from becoming lost. 

Follow-up Target Priorities:

Virtual Impactors: We give NEOs listed by JPL or the Near-Earth Object Dynamics Site (NEODyS) with potential impact solutions the highest priority. Objects are retired from those lists when there are sufficient observations to rule out impact trajectories. Spacewatch observations have contributed to the retirement of half of all the objects that have been so retired.

MPC’s NEO Confirmation Page (NEOCP): Freshly discovered objects, especially those discovered by surveys that cannot do their own followup, receive priority
on each night of observing.

Potentially Hazardous Asteroids: To focus on the Congressional Mandate cited for NASA's Near-Earth Object Observation (NEOO) Program, we also observe PHAs as defined by the International Astronomical Union (IAU). Those are NEOs with absolute V magnitudes “H” brighter or equal to 22 and whose orbits approach within 0.05 AU of the Earth’s orbit. Our tally of observations of PHAs is illustrated here:/sites/spacewatch.lpl.arizona.edu/files/SW_All_PHA_detections_v2.png  .

Radar Targets: We routinely monitor the web sites of the Goldstone and Arecibo Observatories for requests for astrometry of their future asteroid targets. Radar
can provide a wealth of accurate and unique information about asteroids, but their positions on the sky need to be known to within about 20 arcseconds. Astrometry prior to radar campaigns is sometimes needed to improve knowledge of orbits. Per year we observe about 35 radar targets.

NEOs Measured in the Infrared by the NEOWISE or Spitzer Spacecraft: The relationships between the mineralogical properties and orbits of asteroids are clues to their origins and subsequent processing. But albedos are generally difficult to determine in visible light. The Wide-field Infrared Survey Explorer (WISE; later NEOWISE, Wright et al. 2010) has determined diameters and albedos of several hundred NEOs (Mainzer et al. 2011a, b, 2012a,b, Nugent et al. 2015). After such hard-won physical parameters are determined, it is important that those objects be recoverable for further study. We observe about 50 such objects per year.

Potential Destinations of Spacecraft: NASA's NEOO Program wants astrometry of NEOs as potential rendezvous destinations for spacecraft. The orbital criteria for mission feasibility are low inclination with respect to the ecliptic, low eccentricity, and semimajor axis near 1 AU, to minimize the velocity impulse required for transfer and rendezvous. The necessary long-range planning for a space mission requires much more accurate orbital elements than have been typical for NEOs.  Spacewatch observes an average of 100 potential rendezvous targets per year.