Occultation event with (9799) Thronium, event index number 3159
Regions able to see the event: Australia
Geocentric closest approach at 2026/01/19 18:21:42 UTC
J2000 position of star is 10:42:33.1 -29:06:45
Equinox of date position of star is 10:43:46.9 -29:14:58
Star is 124 degrees from the moon. Moon is 1% illuminated.
Stellar brightness G=16.8, apparent brightess of occulting body is G=15.2
Use an exposure time of 1.70 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 18% with SNR of 0.5 for the occulted depth (per occulted point)
Apparent velocity is 14.1 km/sec on the sky relative to the star, or, 14.4 arcsec/hr.
Position angle of asteroid motion is 46.0 degrees
The recommended exposure time corresponds to 24.0 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 33.0 km.
The sky-plane scale is 3532.4 km/arcsec.
Diameter estimates:
71.1 km assuming a 5% albedo, maximum of 5.0 sec for a central chord
29.0 km assuming a 30% albedo, maximum of 2.1 sec for a central chord
Cross-track diameter of 68.0 km used for deployment plan.
Star training set for 9799_Thronium, (2026/01/19 18:22UT) Object RA Dec mag sep mel Bet Cru 12:49:15.7 -59:49:50 1.3 37.17 87 Mu Vel 10:47:53.9 -49:33:29 2.8 20.32 106 PPM 257903 10:37:56.2 -27:47:31 6.5 1.94 126 PPM 258065 10:44:41.7 -29:12:06 8.0 0.21 124 PPM 258028 10:43:38.9 -29:26:45 9.3 0.20 124 9799_Thronium 10:43:46.9 -29:14:58 15.2 124 Positions are for equinox of date
Star training set for 9799_Thronium, (2026/01/19 18:22UT) Object RA Dec mag sep mel Bet Cru 12:47:43.1 -59:41:20 1.3 37.17 87 Mu Vel 10:46:46.5 -49:25:13 2.8 20.32 106 PPM 257903 10:36:42.6 -27:39:23 6.5 1.94 126 PPM 258065 10:43:27.9 -29:03:53 8.0 0.21 124 PPM 258028 10:42:25.2 -29:18:32 9.3 0.20 124 9799_Thronium 10:42:33.1 -29:06:45 15.2 124 Positions are for J2000