Occultation event with (21595) 98WJ5, event index number 3554
Regions able to see the event: Australia
Geocentric closest approach at 2026/03/31 16:58:04 UTC
J2000 position of star is 12:37:36.0 +17:30:09
Equinox of date position of star is 12:38:54.8 +17:21:30
Star is 22 degrees from the moon. Moon is 98% illuminated.
Stellar brightness G=15.7, apparent brightess of occulting body is G=16.1
Use an exposure time of 0.45 seconds with the standard RECON-QHY system.
SNR of 3.5 per integration for unocculted signal
Expected flux drop is 60% with SNR of 2.1 for the occulted depth (per occulted point)
Apparent velocity is 18.6 km/sec on the sky relative to the star, or, 19.2 arcsec/hr.
Position angle of asteroid motion is 122.2 degrees
The recommended exposure time corresponds to 8.4 km per image.
The 1-sigma error in the time of the event is 1.2 seconds.
The 1-sigma cross-track error in the shadow position is 28.9 km.
The sky-plane scale is 3478.6 km/arcsec.
Diameter estimates:
42.1 km assuming a 5% albedo, maximum of 2.3 sec for a central chord
17.2 km assuming a 30% albedo, maximum of 0.9 sec for a central chord
Cross-track diameter of 35.2 km used for deployment plan.
Star training set for 21595_98WJ5, (2026/03/31 16:58UT) Object RA Dec mag sep mel Arcturus 14:16:51.6 +19:02:50 0.0 23.30 43 Vindemiatrix 13:03:29.0 +10:49:07 2.8 8.84 23 PPM 129407 12:53:45.7 +15:58:48 6.3 3.81 24 25 Com 12:38:17.2 +16:56:43 6.7 0.44 22 PPM 129219 12:40:20.8 +17:17:36 9.5 0.35 22 21595_98WJ5 12:38:54.8 +17:21:30 16.1 22 Positions are for equinox of date
Star training set for 21595_98WJ5, (2026/03/31 16:58UT) Object RA Dec mag sep mel Arcturus 14:15:37.7 +19:10:06 0.0 23.30 43 Vindemiatrix 13:02:10.1 +10:57:33 2.8 8.84 23 PPM 129407 12:52:27.3 +16:07:20 6.3 3.81 24 25 Com 12:36:58.3 +17:05:22 6.7 0.44 22 PPM 129219 12:39:02.0 +17:26:14 9.5 0.35 22 21595_98WJ5 12:37:36.0 +17:30:09 16.1 22 Positions are for J2000