Occultation event with (17172) 99NZ41, event index number 4366
Regions able to see the event: SAmericaS
Geocentric closest approach at 2026/10/09 07:18:58 UTC
J2000 position of star is 06:32:41.7 -00:20:46
Equinox of date position of star is 06:34:03.8 -00:22:04
Star is 80 degrees from the moon. Moon is 2% illuminated.
Stellar brightness G=16.6, apparent brightess of occulting body is G=16.4
Use an exposure time of 1.10 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 46% with SNR of 1.4 for the occulted depth (per occulted point)
Apparent velocity is 10.0 km/sec on the sky relative to the star, or, 9.9 arcsec/hr.
Position angle of asteroid motion is 134.4 degrees
The recommended exposure time corresponds to 11.0 km per image.
The 1-sigma error in the time of the event is 1.8 seconds.
The 1-sigma cross-track error in the shadow position is 39.9 km.
The sky-plane scale is 3636.8 km/arcsec.
Diameter estimates:
40.9 km assuming a 5% albedo, maximum of 4.1 sec for a central chord
16.7 km assuming a 30% albedo, maximum of 1.7 sec for a central chord
Cross-track diameter of 34.5 km used for deployment plan.
Star training set for 17172_99NZ41, (2026/10/09 07:19UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.3 +07:24:35 0.4 12.15 90 Saiph 05:49:01.6 -09:39:44 2.1 14.56 91 PPM 176316 06:34:59.5 -01:14:33 5.1 0.90 80 PPM 176317 06:35:05.8 -00:17:13 8.3 0.27 80 PPM 176314 06:34:48.4 -00:27:04 9.4 0.20 80 17172_99NZ41 06:34:03.8 -00:22:04 16.4 80 Positions are for equinox of date
Star training set for 17172_99NZ41, (2026/10/09 07:19UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 12.15 90 Saiph 05:47:45.4 -09:40:11 2.1 14.56 91 PPM 176316 06:33:37.9 -01:13:13 5.1 0.90 80 PPM 176317 06:33:43.6 -00:15:53 8.3 0.27 80 PPM 176314 06:33:26.3 -00:25:44 9.4 0.20 80 17172_99NZ41 06:32:41.7 -00:20:46 16.4 80 Positions are for J2000