Occultation event with (17172) 99NZ41, event index number 3207
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/02/04 01:22:26 UTC
J2000 position of star is 03:48:07.6 -09:47:19
Equinox of date position of star is 03:49:22.8 -09:42:35
Star is 107 degrees from the moon. Moon is 95% illuminated.
Stellar brightness G=14.6, apparent brightess of occulting body is G=16.3
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 8.5 per integration for unocculted signal
Expected flux drop is 83% with SNR of 7.0 for the occulted depth (per occulted point)
Apparent velocity is 17.8 km/sec on the sky relative to the star, or, 18.0 arcsec/hr.
Position angle of asteroid motion is 16.3 degrees
The recommended exposure time corresponds to 8.0 km per image.
The 1-sigma error in the time of the event is 2.4 seconds.
The 1-sigma cross-track error in the shadow position is 1.3 km.
The sky-plane scale is 3557.9 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 0.9 sec for a central chord
Cross-track diameter of 34.5 km used for deployment plan.
Star training set for 17172_99NZ41, (2026/02/04 01:22UT) Object RA Dec mag sep mel Rigel 05:15:47.6 -08:10:24 0.1 21.39 86 Menkar 03:03:38.8 +04:11:26 2.5 17.97 117 23Del Eri 03:44:30.0 -09:40:37 3.5 1.20 109 PPM 186164 03:47:28.5 -09:48:11 7.1 0.48 108 PPM 186212 03:49:56.4 -09:38:31 9.4 0.15 107 17172_99NZ41 03:49:22.8 -09:42:35 16.3 107 Positions are for equinox of date
Star training set for 17172_99NZ41, (2026/02/04 01:22UT) Object RA Dec mag sep mel Rigel 05:14:32.3 -08:12:06 0.1 21.39 86 Menkar 03:02:16.8 +04:05:21 2.5 17.97 117 23Del Eri 03:43:14.7 -09:45:29 3.5 1.20 109 PPM 186164 03:46:13.3 -09:52:58 7.1 0.48 108 PPM 186212 03:48:41.2 -09:43:13 9.4 0.15 107 17172_99NZ41 03:48:07.6 -09:47:19 16.3 107 Positions are for J2000