Occultation event with (21601) 98XO89, event index number 1111
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/07/05 01:05:07 UTC
J2000 position of star is 11:13:58.0 -14:55:56
Equinox of date position of star is 11:15:14.7 -15:04:17
Star is 44 degrees from the moon. Moon is 71% illuminated.
Stellar brightness G=16.3, apparent brightess of occulting body is G=15.7
Use an exposure time of 0.75 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 38% with SNR of 1.1 for the occulted depth (per occulted point)
Apparent velocity is 23.6 km/sec on the sky relative to the star, or, 21.8 arcsec/hr.
The recommended exposure time corresponds to 17.7 km per image.
The 1-sigma error in the time of the event is 2.1 seconds.
The 1-sigma cross-track error in the shadow position is 21.3 km.
The sky-plane scale is 3898.3 km/arcsec.
Diameter estimates:
60.0 km assuming a 5% albedo, aximum of 2.5 sec for a central chord
24.5 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 60.0 km used for deployment plan.
Star training set for 21601_98XO89, (2025/07/05 01:05UT) Object RA Dec mag sep mel Regulus 10:09:43.7 +11:50:30 1.3 31.42 68 4Gam Crv 12:17:07.3 -17:41:00 2.6 15.06 29 12Del Crt 11:20:37.1 -14:55:01 3.6 1.31 42 PPM 224110 11:15:01.4 -15:07:48 8.4 0.08 44 21601_98XO89 11:15:14.7 -15:04:17 15.7 43 Positions are for equinox of date
Star training set for 21601_98XO89, (2025/07/05 01:05UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 31.42 68 4Gam Crv 12:15:48.1 -17:32:30 2.6 15.06 29 12Del Crt 11:19:20.2 -14:46:38 3.6 1.31 42 PPM 224110 11:13:44.7 -14:59:27 8.4 0.08 44 21601_98XO89 11:13:58.0 -14:55:56 15.7 44 Positions are for J2000