Occultation event with (9799) Thronium, event index number 1715
Regions able to see the event: UAE
Geocentric closest approach at 2025/12/23 23:13:28 UTC
J2000 position of star is 10:46:34.4 -26:41:26
Equinox of date position of star is 10:47:48.9 -26:49:40
Star is 130 degrees from the moon. Moon is 14% illuminated.
Stellar brightness G=13.7, apparent brightess of occulting body is G=15.4
Use an exposure time of 0.20 seconds with the standard RECON-QHY system.
SNR of 9.4 per integration for unocculted signal
Expected flux drop is 82% with SNR of 7.7 for the occulted depth (per occulted point)
Apparent velocity is 17.2 km/sec on the sky relative to the star, or, 16.5 arcsec/hr.
Position angle of asteroid motion is 177.6 degrees
The recommended exposure time corresponds to 3.4 km per image.
The 1-sigma error in the time of the event is 1.9 seconds.
The 1-sigma cross-track error in the shadow position is 12.8 km.
The sky-plane scale is 3770.3 km/arcsec.
Diameter estimates:
71.1 km assuming a 5% albedo, aximum of 4.1 sec for a central chord
29.0 km assuming a 30% albedo, maximum of 1.7 sec for a central chord
Cross-track diameter of 68.0 km used for deployment plan.
Star training set for 9799_Thronium, (2025/12/23 23:13UT) Object RA Dec mag sep mel Bet Cru 12:49:15.5 -59:49:49 1.3 39.00 91 4Gam Crv 12:17:08.8 -17:41:10 2.6 22.55 124 PPM 257916 10:38:27.1 -27:32:52 4.9 2.20 131 PPM 258121 10:47:31.7 -26:51:48 7.3 0.07 130 9799_Thronium 10:47:48.9 -26:49:40 15.4 130 Positions are for equinox of date
Star training set for 9799_Thronium, (2025/12/23 23:13UT) Object RA Dec mag sep mel Bet Cru 12:47:43.1 -59:41:20 1.3 39.00 91 4Gam Crv 12:15:48.1 -17:32:30 2.6 22.55 124 PPM 257916 10:37:13.5 -27:24:45 4.9 2.20 131 PPM 258121 10:46:17.3 -26:43:34 7.3 0.07 130 9799_Thronium 10:46:34.4 -26:41:26 15.4 130 Positions are for J2000