Occultation event with (21601) 98XO89, event index number 3450
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/03/17 01:47:29 UTC
J2000 position of star is 13:46:56.7 -31:19:17
Equinox of date position of star is 13:48:27.0 -31:27:05
Star is 113 degrees from the moon. Moon is 5% illuminated.
Stellar brightness G=16.8, apparent brightess of occulting body is G=15.2
Use an exposure time of 1.60 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 20% with SNR of 0.6 for the occulted depth (per occulted point)
Apparent velocity is 10.6 km/sec on the sky relative to the star, or, 11.8 arcsec/hr.
Position angle of asteroid motion is 93.8 degrees
The recommended exposure time corresponds to 17.0 km per image.
The 1-sigma error in the time of the event is 0.8 seconds.
The 1-sigma cross-track error in the shadow position is 35.7 km.
The sky-plane scale is 3252.5 km/arcsec.
Diameter estimates:
60.0 km assuming a 5% albedo, maximum of 5.6 sec for a central chord
24.5 km assuming a 30% albedo, maximum of 2.3 sec for a central chord
Cross-track diameter of 54.9 km used for deployment plan.
Star training set for 21601_98XO89, (2026/03/17 01:47UT) Object RA Dec mag sep mel Spica 13:26:34.7 -11:17:50 1.0 20.78 127 5The Cen 14:08:14.1 -36:29:51 2.1 6.50 107 4 Cen 13:54:43.6 -32:03:21 4.4 1.46 112 PPM 291840 13:49:54.0 -30:52:45 8.2 0.65 113 PPM 291852 13:50:30.1 -31:30:43 9.0 0.44 113 PPM 291804 13:48:11.9 -31:39:10 10.1 0.21 113 21601_98XO89 13:48:27.0 -31:27:05 15.2 113 Positions are for equinox of date
Star training set for 21601_98XO89, (2026/03/17 01:47UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 20.78 127 5The Cen 14:06:39.9 -36:22:25 2.1 6.50 107 4 Cen 13:53:12.5 -31:55:39 4.4 1.46 112 PPM 291840 13:48:23.9 -30:44:58 8.2 0.65 113 PPM 291852 13:48:59.6 -31:22:56 9.0 0.44 113 PPM 291804 13:46:41.6 -31:31:21 10.1 0.21 113 21601_98XO89 13:46:56.7 -31:19:17 15.2 113 Positions are for J2000