Occultation event with (17171) 99NB38, event index number 4713
Regions able to see the event: SMexico
Geocentric closest approach at 2026/11/16 05:51:29 UTC
J2000 position of star is 06:16:46.7 +47:17:51
Equinox of date position of star is 06:18:48.1 +47:17:09
Star is 138 degrees from the moon. Moon is 38% illuminated.
Stellar brightness G=14.3, apparent brightess of occulting body is G=15.9
Use an exposure time of 0.40 seconds with the standard RECON-QHY system.
SNR of 9.9 per integration for unocculted signal
Expected flux drop is 82% with SNR of 8.1 for the occulted depth (per occulted point)
Apparent velocity is 12.3 km/sec on the sky relative to the star, or, 13.2 arcsec/hr.
Position angle of asteroid motion is 109.4 degrees
The recommended exposure time corresponds to 4.9 km per image.
The 1-sigma error in the time of the event is 1.5 seconds.
The 1-sigma cross-track error in the shadow position is 22.4 km.
The sky-plane scale is 3358.2 km/arcsec.
Diameter estimates:
46.1 km assuming a 5% albedo, maximum of 3.8 sec for a central chord
18.8 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 40.9 km used for deployment plan.
Star training set for 17171_99NB38, (2026/11/16 05:51UT) Object RA Dec mag sep mel Pollux 07:46:57.5 +27:57:33 1.1 25.86 162 34Bet Aur 06:01:30.1 +44:56:50 1.9 3.80 136 PPM 049066 06:29:52.3 +47:23:10 6.3 1.88 139 PPM 048953 06:21:06.3 +47:22:51 7.2 0.40 138 PPM 048894 06:17:38.5 +47:23:37 9.1 0.22 137 PPM 048909 06:18:49.5 +47:20:01 10.4 0.05 138 17171_99NB38 06:18:48.1 +47:17:09 15.9 138 Positions are for equinox of date
Star training set for 17171_99NB38, (2026/11/16 05:51UT) Object RA Dec mag sep mel Pollux 07:45:17.7 +28:01:33 1.1 25.86 162 34Bet Aur 05:59:31.6 +44:56:51 1.9 3.80 136 PPM 049066 06:27:50.9 +47:24:18 6.3 1.88 139 PPM 048953 06:19:04.8 +47:23:38 7.2 0.40 138 PPM 048894 06:15:37.0 +47:24:16 9.1 0.22 137 PPM 048909 06:16:48.0 +47:20:42 10.4 0.05 138 17171_99NB38 06:16:46.7 +47:17:51 15.9 138 Positions are for J2000