Occultation event with (9799) Thronium, event index number 3773
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/06/01 01:06:39 UTC
J2000 position of star is 10:11:44.7 -22:36:18
Equinox of date position of star is 10:12:59.2 -22:44:10
Star is 91 degrees from the moon. Moon is 99% illuminated.
Stellar brightness G=16.6, apparent brightess of occulting body is G=15.4
Use an exposure time of 1.20 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 26% with SNR of 0.8 for the occulted depth (per occulted point)
Apparent velocity is 17.7 km/sec on the sky relative to the star, or, 16.7 arcsec/hr.
Position angle of asteroid motion is 58.9 degrees
The recommended exposure time corresponds to 21.2 km per image.
The 1-sigma error in the time of the event is 0.1 seconds.
The 1-sigma cross-track error in the shadow position is 34.4 km.
The sky-plane scale is 3817.9 km/arcsec.
Diameter estimates:
71.1 km assuming a 5% albedo, maximum of 4.0 sec for a central chord
29.0 km assuming a 30% albedo, maximum of 1.6 sec for a central chord
Cross-track diameter of 68.0 km used for deployment plan.
Star training set for 9799_Thronium, (2026/06/01 01:07UT) Object RA Dec mag sep mel Regulus 10:09:46.6 +11:50:13 1.3 34.58 108 Alphard 09:28:53.1 -08:46:28 2.0 17.52 107 PPM 257378 10:15:23.2 -23:56:44 6.1 1.33 90 PPM 257332 10:13:05.9 -22:45:44 8.5 0.04 91 9799_Thronium 10:12:59.2 -22:44:10 15.4 90 Positions are for equinox of date
Star training set for 9799_Thronium, (2026/06/01 01:07UT) Object RA Dec mag sep mel Regulus 10:08:21.9 +11:58:02 1.3 34.58 108 Alphard 09:27:35.2 -08:39:30 2.0 17.52 107 PPM 257378 10:14:08.9 -23:48:49 6.1 1.33 90 PPM 257332 10:11:51.3 -22:37:52 8.5 0.04 91 9799_Thronium 10:11:44.7 -22:36:18 15.4 91 Positions are for J2000