Occultation event with (21601) 98XO89, event index number 3597
Regions able to see the event: SAmericaS
Geocentric closest approach at 2026/04/08 05:45:43 UTC
J2000 position of star is 13:36:48.5 -30:44:27
Equinox of date position of star is 13:38:17.9 -30:52:27
Star is 54 degrees from the moon. Moon is 68% illuminated.
Stellar brightness G=14.5, apparent brightess of occulting body is G=15.0
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 9.4 per integration for unocculted signal
Expected flux drop is 61% with SNR of 5.8 for the occulted depth (per occulted point)
Apparent velocity is 15.8 km/sec on the sky relative to the star, or, 18.2 arcsec/hr.
Position angle of asteroid motion is 112.7 degrees
The recommended exposure time corresponds to 7.9 km per image.
The 1-sigma error in the time of the event is 1.3 seconds.
The 1-sigma cross-track error in the shadow position is 30.8 km.
The sky-plane scale is 3139.9 km/arcsec.
Diameter estimates:
60.0 km assuming a 5% albedo, maximum of 3.8 sec for a central chord
24.5 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 54.9 km used for deployment plan.
Star training set for 21601_98XO89, (2026/04/08 05:46UT) Object RA Dec mag sep mel Spica 13:26:34.8 -11:17:51 1.0 19.76 63 Iot Cen 13:22:05.0 -36:51:00 2.8 6.86 55 PPM 261770 13:34:04.1 -28:49:38 5.7 2.24 55 PPM 291662 13:40:53.6 -31:01:06 8.4 0.57 53 PPM 291597 13:38:04.1 -31:03:56 9.4 0.20 54 21601_98XO89 13:38:17.9 -30:52:27 15.0 53 Positions are for equinox of date
Star training set for 21601_98XO89, (2026/04/08 05:46UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 19.76 63 Iot Cen 13:20:35.1 -36:42:46 2.8 6.86 55 PPM 261770 13:32:35.7 -28:41:35 5.7 2.24 55 PPM 291662 13:39:24.0 -30:53:09 8.4 0.57 53 PPM 291597 13:36:34.6 -30:55:56 9.4 0.20 54 21601_98XO89 13:36:48.5 -30:44:27 15.0 54 Positions are for J2000