Occultation event with (17172) 99NZ41, event index number 5201
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/12/13 03:47:04 UTC
J2000 position of star is 06:19:15.5 -01:51:46
Equinox of date position of star is 06:20:37.2 -01:52:33
Star is 140 degrees from the moon. Moon is 14% illuminated.
Stellar brightness G=16.0, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.55 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 48% with SNR of 1.5 for the occulted depth (per occulted point)
Apparent velocity is 17.5 km/sec on the sky relative to the star, or, 19.9 arcsec/hr.
Position angle of asteroid motion is 98.0 degrees
The recommended exposure time corresponds to 9.6 km per image.
The 1-sigma error in the time of the event is 0.5 seconds.
The 1-sigma cross-track error in the shadow position is 43.1 km.
The sky-plane scale is 3163.5 km/arcsec.
Diameter estimates:
40.9 km assuming a 5% albedo, maximum of 2.3 sec for a central chord
16.7 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 34.5 km used for deployment plan.
Star training set for 17172_99NZ41, (2026/12/13 03:47UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.9 +07:24:35 0.4 11.05 140 Saiph 05:49:02.1 -09:39:43 2.1 11.06 129 PPM 189057 06:21:20.6 -02:57:29 5.2 1.10 140 PPM 176216 06:21:37.9 -02:04:07 7.5 0.32 140 PPM 176211 06:20:49.8 -01:43:49 9.0 0.15 140 17172_99NZ41 06:20:37.2 -01:52:33 15.9 141 Positions are for equinox of date
Star training set for 17172_99NZ41, (2026/12/13 03:47UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 11.05 140 Saiph 05:47:45.4 -09:40:11 2.1 11.06 129 PPM 189057 06:19:59.6 -02:56:40 5.2 1.10 140 PPM 176216 06:20:16.3 -02:03:18 7.5 0.32 140 PPM 176211 06:19:28.0 -01:43:02 9.0 0.15 140 17172_99NZ41 06:19:15.5 -01:51:46 15.9 140 Positions are for J2000