Occultation event with (21601) 98XO89, event index number 3748
Regions able to see the event: Australia
Geocentric closest approach at 2026/05/16 13:23:55 UTC
J2000 position of star is 13:18:30.6 -27:59:10
Equinox of date position of star is 13:19:58.1 -28:07:27
Star is 154 degrees from the moon. Moon is 0% illuminated.
Stellar brightness G=16.3, apparent brightess of occulting body is G=15.1
Use an exposure time of 0.85 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 25% with SNR of 0.8 for the occulted depth (per occulted point)
Apparent velocity is 15.3 km/sec on the sky relative to the star, or, 17.3 arcsec/hr.
Position angle of asteroid motion is 138.2 degrees
The recommended exposure time corresponds to 13.0 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 17.5 km.
The sky-plane scale is 3176.3 km/arcsec.
Diameter estimates:
60.0 km assuming a 5% albedo, maximum of 3.9 sec for a central chord
24.5 km assuming a 30% albedo, maximum of 1.6 sec for a central chord
Cross-track diameter of 54.9 km used for deployment plan.
Star training set for 21601_98XO89, (2026/05/16 13:24UT) Object RA Dec mag sep mel Spica 13:26:35.2 -11:17:53 1.0 16.90 152 Iot Cen 13:22:05.3 -36:51:02 2.8 8.74 152 PPM 261317 13:13:05.7 -26:41:28 6.5 2.09 153 PPM 261523 13:21:57.3 -27:32:52 7.8 0.72 154 PPM 261495 13:20:48.5 -28:01:53 9.6 0.21 154 21601_98XO89 13:19:58.1 -28:07:27 15.1 154 Positions are for equinox of date
Star training set for 21601_98XO89, (2026/05/16 13:24UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 16.90 152 Iot Cen 13:20:35.1 -36:42:46 2.8 8.74 152 PPM 261317 13:11:39.1 -26:33:06 6.5 2.09 153 PPM 261523 13:20:29.8 -27:24:36 7.8 0.72 154 PPM 261495 13:19:21.0 -27:53:36 9.6 0.21 154 21601_98XO89 13:18:30.6 -27:59:10 15.1 154 Positions are for J2000