Occultation event with (9799) Thronium, event index number 3414
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/03/13 00:50:54 UTC
J2000 position of star is 10:16:51.3 -29:15:41
Equinox of date position of star is 10:18:03.3 -29:23:35
Star is 104 degrees from the moon. Moon is 35% illuminated.
Stellar brightness G=16.5, apparent brightess of occulting body is G=14.9
Use an exposure time of 1.25 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 19% with SNR of 0.6 for the occulted depth (per occulted point)
Apparent velocity is 17.4 km/sec on the sky relative to the star, or, 18.9 arcsec/hr.
Position angle of asteroid motion is 118.7 degrees
The recommended exposure time corresponds to 21.8 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 19.7 km.
The sky-plane scale is 3322.8 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, (2026/03/13 00:51UT) Object RA Dec mag sep mel Bet Cru 12:49:16.2 -59:49:53 1.3 39.62 66 Lam Vel 09:08:57.7 -43:32:22 2.2 19.75 102 PPM 257470 10:19:19.8 -29:07:26 5.3 0.39 104 PPM 257425 10:17:31.0 -29:06:36 8.1 0.31 104 PPM 257463 10:18:58.8 -29:22:01 8.6 0.20 104 9799_Thronium 10:18:03.3 -29:23:35 14.9 104 Positions are for equinox of date
Star training set for 9799_Thronium, (2026/03/13 00:51UT) Object RA Dec mag sep mel Bet Cru 12:47:43.1 -59:41:20 1.3 39.62 66 Lam Vel 09:07:59.7 -43:25:57 2.2 19.75 102 PPM 257470 10:18:07.6 -28:59:31 5.3 0.39 104 PPM 257425 10:16:18.9 -28:58:43 8.1 0.31 104 PPM 257463 10:17:46.6 -29:14:06 8.6 0.20 104 9799_Thronium 10:16:51.3 -29:15:41 14.9 104 Positions are for J2000