Occultation event with (17172) 99NZ41, event index number 4335
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/10/01 04:28:20 UTC
J2000 position of star is 06:30:45.5 +00:01:52
Equinox of date position of star is 06:32:07.8 +00:00:38
Star is 42 degrees from the moon. Moon is 76% illuminated.
Stellar brightness G=16.1, apparent brightess of occulting body is G=16.5
Use an exposure time of 0.65 seconds with the standard RECON-QHY system.
SNR of 3.2 per integration for unocculted signal
Expected flux drop is 58% with SNR of 1.9 for the occulted depth (per occulted point)
Apparent velocity is 13.2 km/sec on the sky relative to the star, or, 12.8 arcsec/hr.
Position angle of asteroid motion is 122.9 degrees
The recommended exposure time corresponds to 8.6 km per image.
The 1-sigma error in the time of the event is 0.7 seconds.
The 1-sigma cross-track error in the shadow position is 42.1 km.
The sky-plane scale is 3719.3 km/arcsec.
Diameter estimates:
40.9 km assuming a 5% albedo, maximum of 3.1 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, (2026/10/01 04:28UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.2 +07:24:35 0.4 11.54 30 Saiph 05:49:01.6 -09:39:44 2.1 14.44 43 PPM 150595 06:30:14.7 +00:06:32 6.3 0.48 42 PPM 176289 06:31:08.8 -00:07:02 8.5 0.28 42 PPM 176290 06:31:41.4 -00:02:54 9.0 0.12 42 17172_99NZ41 06:32:07.8 +00:00:38 16.5 42 Positions are for equinox of date
Star training set for 17172_99NZ41, (2026/10/01 04:28UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 11.54 30 Saiph 05:47:45.4 -09:40:11 2.1 14.44 43 PPM 150595 06:28:52.4 +00:07:41 6.3 0.48 42 PPM 176289 06:29:46.6 -00:05:51 8.5 0.28 42 PPM 176290 06:30:19.2 -00:01:42 9.0 0.12 42 17172_99NZ41 06:30:45.5 +00:01:52 16.5 42 Positions are for J2000