Occultation event with (21601) 98XO89, event index number 929
Regions able to see the event: Europe
Geocentric closest approach at 2025/04/25 18:24:46 UTC
J2000 position of star is 10:55:55.7 -17:50:31
Equinox of date position of star is 10:57:10.5 -17:58:39
Star is 154 degrees from the moon. Moon is 6% illuminated.
Stellar brightness G=15.3, apparent brightess of occulting body is G=15.2
Use an exposure time of 1.25 seconds with the standard RECON-QHY system.
SNR of 9.0 per integration for unocculted signal
Expected flux drop is 47% with SNR of 4.3 for the occulted depth (per occulted point)
Apparent velocity is 11.6 km/sec on the sky relative to the star, or, 13.0 arcsec/hr.
The recommended exposure time corresponds to 14.5 km per image.
The 1-sigma error in the time of the event is 2.0 seconds.
The 1-sigma cross-track error in the shadow position is 38.5 km.
The sky-plane scale is 3209.9 km/arcsec.
Diameter estimates:
60.0 km assuming a 5% albedo, aximum of 5.2 sec for a central chord
24.5 km assuming a 30% albedo, maximum of 2.1 sec for a central chord
Cross-track diameter of 60.0 km used for deployment plan.
Star training set for 21601_98XO89, (2025/04/25 18:25UT) Object RA Dec mag sep mel Regulus 10:09:43.1 +11:50:33 1.3 32.04 143 4Gam Crv 12:17:06.7 -17:40:56 2.6 19.02 166 7Alp Crt 11:01:00.6 -18:26:03 4.1 1.02 155 PPM 223690 10:58:00.8 -17:35:20 8.1 0.44 155 PPM 223677 10:57:28.5 -17:52:16 9.3 0.13 154 21601_98XO89 10:57:10.5 -17:58:39 15.2 154 Positions are for equinox of date
Star training set for 21601_98XO89, (2025/04/25 18:25UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 32.04 143 4Gam Crv 12:15:48.1 -17:32:30 2.6 19.02 166 7Alp Crt 10:59:45.7 -18:17:52 4.1 1.02 155 PPM 223690 10:56:45.9 -17:27:11 8.1 0.44 155 PPM 223677 10:56:13.6 -17:44:08 9.3 0.13 154 21601_98XO89 10:55:55.7 -17:50:31 15.2 154 Positions are for J2000