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.