Occultation event with (17172) 99NZ41, event index number 1355
Regions able to see the event: NZ
Geocentric closest approach at 2025/10/10 15:56:07 UTC
J2000 position of star is 04:27:08.1 -12:26:42
Equinox of date position of star is 04:28:20.4 -12:23:19
Star is 39 degrees from the moon. Moon is 83% illuminated.
Stellar brightness G=14.4, apparent brightess of occulting body is G=16.0
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 9.8 per integration for unocculted signal
Expected flux drop is 81% with SNR of 7.9 for the occulted depth (per occulted point)
Apparent velocity is 12.5 km/sec on the sky relative to the star, or, 14.1 arcsec/hr.
Position angle of asteroid motion is 30.6 degrees
The recommended exposure time corresponds to 5.6 km per image.
The 1-sigma error in the time of the event is 3.3 seconds.
The 1-sigma cross-track error in the shadow position is 8.3 km.
The sky-plane scale is 3200.4 km/arcsec.
Diameter estimates:
40.9 km assuming a 5% albedo, aximum of 3.3 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, (2025/10/10 15:56UT) Object RA Dec mag sep mel Rigel 05:15:46.7 -08:10:26 0.1 12.40 38 67Bet Eri 05:09:07.1 -05:03:18 2.8 12.46 34 PPM 214397 04:30:18.8 -12:59:36 5.6 0.77 40 PPM 214373 04:29:23.2 -12:12:35 8.3 0.31 39 PPM 214364 04:29:07.5 -12:30:39 9.3 0.23 39 17172_99NZ41 04:28:20.4 -12:23:19 16.0 39 Positions are for equinox of date
Star training set for 17172_99NZ41, (2025/10/10 15:56UT) Object RA Dec mag sep mel Rigel 05:14:32.3 -08:12:06 0.1 12.40 38 67Bet Eri 05:07:50.8 -05:05:13 2.8 12.46 34 PPM 214397 04:29:06.9 -13:02:54 5.6 0.77 40 PPM 214373 04:28:10.8 -12:15:55 8.3 0.31 39 PPM 214364 04:27:55.3 -12:34:00 9.3 0.23 39 17172_99NZ41 04:27:08.1 -12:26:42 16.0 39 Positions are for J2000