Occultation event with (17172) 99NZ41, event index number 4852
Regions able to see the event: US,RECON,UVa
Geocentric closest approach at 2026/11/24 07:41:09 UTC
J2000 position of star is 06:27:57.5 -01:54:59
Equinox of date position of star is 06:29:19.0 -01:56:06
Star is 49 degrees from the moon. Moon is 100% illuminated.
Stellar brightness G=14.8, apparent brightess of occulting body is G=16.0
Use an exposure time of 0.65 seconds with the standard RECON-QHY system.
SNR of 9.6 per integration for unocculted signal
Expected flux drop is 76% with SNR of 7.3 for the occulted depth (per occulted point)
Apparent velocity is 13.0 km/sec on the sky relative to the star, or, 14.4 arcsec/hr.
Position angle of asteroid motion is 83.0 degrees
The recommended exposure time corresponds to 8.4 km per image.
The 1-sigma error in the time of the event is 1.6 seconds.
The 1-sigma cross-track error in the shadow position is 39.2 km.
The sky-plane scale is 3243.1 km/arcsec.
Diameter estimates:
40.9 km assuming a 5% albedo, maximum of 3.2 sec for a central chord
16.7 km assuming a 30% albedo, maximum of 1.3 sec for a central chord
Cross-track diameter of 34.5 km used for deployment plan.
Star training set for 17172_99NZ41, (2026/11/24 07:41UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.7 +07:24:35 0.4 12.40 37 Saiph 05:49:02.0 -09:39:44 2.1 12.65 47 PPM 176266 06:28:01.3 -01:31:31 5.9 0.52 49 PPM 176283 06:29:57.6 -01:36:30 7.8 0.36 49 PPM 176274 06:28:56.0 -02:13:40 8.9 0.31 49 PPM 176282 06:29:49.8 -01:46:50 10.2 0.20 49 17172_99NZ41 06:29:19.0 -01:56:06 16.0 49 Positions are for equinox of date
This table contains the target star visibility for registered US sites that are relevant for this occultation. This list has been filtered to only those sites that can see the field and are within range of the shadow given the uncertainties. The observing time range has been calculated to cover the time of the event at each site with allowances for the event timing uncertainty plus time for obtaining a pre and post event baseline lightcurve. This set of stations has a 21.4 % chance of getting at least one chord. There is a 0.0% chance of 2 or more chords assuming clear weather for all.
| Site Name | Site mid-time (UT) |
Sun alt (deg) |
Sky | Moon | Star alt (deg) |
Star az (deg) |
Target | Observing Time | Xtrack (km) |
Prob |
|---|---|---|---|---|---|---|---|---|---|---|
| Naylor Obs | 07:39:57 | -49.7 | Dark | Up | 47.7 | 186.5 | Up | 07:37:29-07:43:29 | 107.1 | 0.008 | Ryan Obs | 07:39:53 | -49.4 | Dark | Up | 48.0 | 187.5 | Up | 07:39:15-07:45:15 | 76.2 | 0.051 | Patrick | 07:43:13 | -71.5 | Dark | Up | 46.8 | 143.6 | Up | 07:37:01-07:43:01 | -46.2 | 0.149 | George/Scottsdale | 07:43:52 | -75.3 | Dark | Up | 44.8 | 136.0 | Up | 07:37:58-07:43:58 | -111.4 | 0.006 |
This table contains the target star visibility for registered RECON sites that are relevant for this occultation. This list has been filtered to only those sites that can see the field and are within range of the shadow given the uncertainties. The observing time range has been calculated to cover the time of the event at each site with allowances for the event timing uncertainty plus time for obtaining a pre and post event baseline lightcurve. This set of stations has a 53.9 % chance of getting at least one chord. There is a 40.7% chance of 2 or more chords assuming clear weather for all.
| Site Name | Site mid-time (UT) |
Sun alt (deg) |
Sky | Moon | Star alt (deg) |
Star az (deg) |
Target | Observing Time | Xtrack (km) |
Prob |
|---|---|---|---|---|---|---|---|---|---|---|
| North Las Vegas | 07:44:03 | -73.8 | Dark | Up | 41.0 | 133.9 | Low | 07:40:33-07:46:33 | 135.4 | 0.001 | Laughlin/Bullhead City | 07:44:03 | -74.8 | Dark | Up | 42.2 | 133.9 | Low | 07:40:53-07:46:53 | 32.6 | 0.208 | Kingman/Dolan Springs | 07:44:00 | -74.7 | Dark | Up | 42.5 | 134.5 | Low | 07:40:32-07:46:32 | 31.1 | 0.217 | Lake Havasu City | 07:44:04 | -75.4 | Dark | Up | 42.8 | 133.8 | Low | 07:40:30-07:46:30 | -26.2 | 0.239 | Wildwood | 07:44:30 | -76.5 | Dark | Up | 40.5 | 129.1 | Up | 07:39:20-07:45:20 | -29.7 | 0.224 | Idyllwild | 07:44:20 | -76.6 | Dark | Up | 41.9 | 130.8 | Up | 07:41:30-07:47:30 | -72.9 | 0.056 | Calipatria | 07:44:16 | -77.0 | Dark | Up | 43.0 | 131.6 | Up | 07:40:44-07:46:44 | -135.1 | 0.001 | Yuma | 07:44:12 | -77.2 | Dark | Up | 43.9 | 132.2 | Up | 07:41:03-07:47:03 | -179.2 | 0.000 |
This table contains the target star visibility for registered UVa sites that are relevant for this occultation. This list has been filtered to only those sites that can see the field and are within range of the shadow given the uncertainties. The observing time range has been calculated to cover the time of the event at each site with allowances for the event timing uncertainty plus time for obtaining a pre and post event baseline lightcurve. This set of stations has a 57.4 % chance of getting at least one chord. There is a 28.9% chance of 2 or more chords assuming clear weather for all.
| Site Name | Site mid-time (UT) |
Sun alt (deg) |
Sky | Moon | Star alt (deg) |
Star az (deg) |
Target | Observing Time | Xtrack (km) |
Prob |
|---|---|---|---|---|---|---|---|---|---|---|
| Green_Bank | 07:40:17 | -52.3 | Dark | Up | 49.6 | 182.4 | Up | 07:37:08-07:43:08 | -6.2 | 0.294 | Culpeper | 07:40:05 | -51.0 | Dark | Up | 49.5 | 185.1 | Up | 07:37:09-07:43:09 | -21.6 | 0.256 | Crozet | 07:40:09 | -51.6 | Dark | Up | 49.9 | 184.2 | Up | 07:37:05-07:43:05 | -48.0 | 0.143 | Charlottesville | 07:40:08 | -51.5 | Dark | Up | 50.0 | 184.4 | Up | 07:37:05-07:43:05 | -53.7 | 0.120 | Lake_Anna | 07:40:05 | -51.0 | Dark | Up | 49.9 | 185.3 | Up | 07:37:13-07:43:13 | -61.3 | 0.092 | Lynchburg | 07:40:13 | -52.1 | Dark | Up | 50.6 | 183.5 | Up | 07:37:17-07:43:17 | -101.4 | 0.012 | Richmond | 07:40:01 | -50.8 | Dark | Up | 50.4 | 186.1 | Up | 07:37:01-07:43:01 | -105.0 | 0.009 |
Star training set for 17172_99NZ41, (2026/11/24 07:41UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 12.40 37 Saiph 05:47:45.4 -09:40:11 2.1 12.65 47 PPM 176266 06:26:39.6 -01:30:27 5.9 0.52 49 PPM 176283 06:28:35.9 -01:35:22 7.8 0.36 49 PPM 176274 06:27:34.7 -02:12:34 8.9 0.31 49 PPM 176282 06:28:28.2 -01:45:42 10.2 0.20 49 17172_99NZ41 06:27:57.5 -01:54:59 16.0 49 Positions are for J2000