Occultation event with (21601) 98XO89, event index number 881
Regions able to see the event: SAmericaS
Geocentric closest approach at 2025/04/04 08:24:50 UTC
J2000 position of star is 11:01:56.2 -19:32:19
Equinox of date position of star is 11:03:10.9 -19:40:30
Star is 82 degrees from the moon. Moon is 42% illuminated.
Stellar brightness G=12.6, apparent brightess of occulting body is G=15.0
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 14.4 per integration for unocculted signal
Expected flux drop is 90% with SNR of 13.0 for the occulted depth (per occulted point)
Apparent velocity is 15.5 km/sec on the sky relative to the star, or, 18.0 arcsec/hr.
The recommended exposure time corresponds to 1.9 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 29.0 km.
The sky-plane scale is 3094.5 km/arcsec.
Diameter estimates:
59.7 km assuming a 5% albedo, aximum of 3.9 sec for a central chord
24.4 km assuming a 30% albedo, maximum of 1.6 sec for a central chord
Cross-track diameter of 59.7 km used for deployment plan.
Star training set for 21601_98XO89, (2025/04/04 08:25UT) Object RA Dec mag sep mel Regulus 10:09:42.9 +11:50:34 1.3 34.16 54 4Gam Crv 12:17:06.5 -17:40:55 2.6 17.61 96 7Alp Crt 11:01:00.4 -18:26:02 4.1 1.34 81 PPM 223791 11:01:52.2 -19:28:44 7.4 0.37 82 PPM 223829 11:03:19.1 -19:34:44 9.5 0.10 82 21601_98XO89 11:03:10.9 -19:40:30 15.0 83 Positions are for equinox of date
Star training set for 21601_98XO89, (2025/04/04 08:25UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 34.16 54 4Gam Crv 12:15:48.1 -17:32:30 2.6 17.61 96 7Alp Crt 10:59:45.7 -18:17:52 4.1 1.34 81 PPM 223791 11:00:37.5 -19:20:34 7.4 0.37 82 PPM 223829 11:02:04.4 -19:26:33 9.5 0.10 82 21601_98XO89 11:01:56.2 -19:32:19 15.0 82 Positions are for J2000