Occultation event with (9799) Thronium, event index number 3426
Regions able to see the event: Australia
Geocentric closest approach at 2026/03/14 18:36:28 UTC
J2000 position of star is 10:15:59.0 -29:09:12
Equinox of date position of star is 10:17:11.1 -29:17:04
Star is 121 degrees from the moon. Moon is 20% illuminated.
Stellar brightness G=15.6, apparent brightess of occulting body is G=14.9
Use an exposure time of 0.95 seconds with the standard RECON-QHY system.
SNR of 5.6 per integration for unocculted signal
Expected flux drop is 34% with SNR of 1.9 for the occulted depth (per occulted point)
Apparent velocity is 17.4 km/sec on the sky relative to the star, or, 18.8 arcsec/hr.
Position angle of asteroid motion is 120.6 degrees
The recommended exposure time corresponds to 16.5 km per image.
The 1-sigma error in the time of the event is 1.7 seconds.
The 1-sigma cross-track error in the shadow position is 18.5 km.
The sky-plane scale is 3323.9 km/arcsec.
Diameter estimates:
71.1 km assuming a 5% albedo, maximum 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, (2026/03/14 18:36UT) Object RA Dec mag sep mel Bet Cru 12:49:16.3 -59:49:53 1.3 39.81 81 Lam Vel 09:08:57.7 -43:32:22 2.2 19.71 113 PPM 257470 10:19:19.8 -29:07:26 5.3 0.50 121 PPM 257425 10:17:31.0 -29:06:36 8.1 0.19 121 9799_Thronium 10:17:11.1 -29:17:04 14.9 121 Positions are for equinox of date
Star training set for 9799_Thronium, (2026/03/14 18:36UT) Object RA Dec mag sep mel Bet Cru 12:47:43.1 -59:41:20 1.3 39.81 81 Lam Vel 09:07:59.7 -43:25:57 2.2 19.71 113 PPM 257470 10:18:07.6 -28:59:31 5.3 0.50 121 PPM 257425 10:16:18.9 -28:58:43 8.1 0.19 121 9799_Thronium 10:15:59.0 -29:09:12 14.9 121 Positions are for J2000