Occultation event with (17172) 99NZ41, event index number 4392
Regions able to see the event: SAfrica
Geocentric closest approach at 2026/10/14 00:58:56 UTC
J2000 position of star is 06:33:27.2 -00:33:50
Equinox of date position of star is 06:34:49.2 -00:35:10
Star is 132 degrees from the moon. Moon is 12% illuminated.
Stellar brightness G=11.0, apparent brightess of occulting body is G=16.4
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 37.6 per integration for unocculted signal
Expected flux drop is 99% with SNR of 37.3 for the occulted depth (per occulted point)
Apparent velocity is 8.4 km/sec on the sky relative to the star, or, 8.4 arcsec/hr.
Position angle of asteroid motion is 144.4 degrees
The recommended exposure time corresponds to 1.0 km per image.
The 1-sigma error in the time of the event is 2.8 seconds.
The 1-sigma cross-track error in the shadow position is 35.4 km.
The sky-plane scale is 3589.2 km/arcsec.
Diameter estimates:
40.9 km assuming a 5% albedo, maximum of 4.9 sec for a central chord
16.7 km assuming a 30% albedo, maximum of 2.0 sec for a central chord
Cross-track diameter of 34.5 km used for deployment plan.
Star training set for 17172_99NZ41, (2026/10/14 00:59UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.4 +07:24:35 0.4 12.44 145 Saiph 05:49:01.7 -09:39:44 2.1 14.56 134 PPM 176316 06:34:59.5 -01:14:33 5.1 0.66 132 PPM 176317 06:35:05.8 -00:17:13 8.3 0.31 132 PPM 176313 06:34:38.0 -00:35:47 9.7 0.05 132 17172_99NZ41 06:34:49.2 -00:35:10 16.4 132 Positions are for equinox of date
Star training set for 17172_99NZ41, (2026/10/14 00:59UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 12.44 145 Saiph 05:47:45.4 -09:40:11 2.1 14.56 134 PPM 176316 06:33:37.9 -01:13:13 5.1 0.66 132 PPM 176317 06:33:43.6 -00:15:53 8.3 0.31 132 PPM 176313 06:33:16.0 -00:34:28 9.7 0.05 132 17172_99NZ41 06:33:27.2 -00:33:50 16.4 132 Positions are for J2000