Occultation event with (17171) 99NB38, event index number 1054
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/06/13 09:39:54 UTC
J2000 position of star is 02:28:28.2 +37:38:48
Equinox of date position of star is 02:30:02.3 +37:45:33
Star is 120 degrees from the moon. Moon is 96% illuminated.
Stellar brightness G=16.1, apparent brightess of occulting body is G=16.3
Use an exposure time of 0.60 seconds with the standard RECON-QHY system.
SNR of 3.2 per integration for unocculted signal
Expected flux drop is 55% with SNR of 1.8 for the occulted depth (per occulted point)
Apparent velocity is 37.7 km/sec on the sky relative to the star, or, 32.3 arcsec/hr.
The recommended exposure time corresponds to 22.6 km per image.
The 1-sigma error in the time of the event is 1.2 seconds.
The 1-sigma cross-track error in the shadow position is 31.4 km.
The sky-plane scale is 4201.8 km/arcsec.
Diameter estimates:
46.1 km assuming a 5% albedo, aximum of 1.2 sec for a central chord
18.8 km assuming a 30% albedo, maximum of 0.5 sec for a central chord
Cross-track diameter of 46.1 km used for deployment plan.
Star training set for 17171_99NB38, (2025/06/13 09:40UT) Object RA Dec mag sep mel Aldebaran 04:37:23.0 +16:33:30 0.8 35.08 142 57Gam1And 02:05:28.4 +42:27:02 2.3 6.64 117 14 Tri 02:33:39.9 +36:15:31 5.1 1.67 120 PPM 067382 02:30:41.7 +37:26:31 7.0 0.34 120 PPM 067352 02:29:08.8 +37:34:55 10.0 0.25 120 17171_99NB38 02:30:02.3 +37:45:33 16.3 120 Positions are for equinox of date
Star training set for 17171_99NB38, (2025/06/13 09:40UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 35.08 142 57Gam1And 02:03:54.1 +42:19:46 2.3 6.64 117 14 Tri 02:32:06.3 +36:08:50 5.1 1.67 120 PPM 067382 02:29:07.6 +37:19:46 7.0 0.34 120 PPM 067352 02:27:34.8 +37:28:08 10.0 0.25 120 17171_99NB38 02:28:28.2 +37:38:48 16.3 120 Positions are for J2000