Occultation event with (9799) Thronium, event index number 841
Regions able to see the event: Europe
Geocentric closest approach at 2025/03/21 22:37:44 UTC
J2000 position of star is 08:13:31.0 -11:19:46
Equinox of date position of star is 08:14:42.9 -11:24:25
Star is 125 degrees from the moon. Moon is 55% illuminated.
Stellar brightness G=15.2, apparent brightess of occulting body is G=15.1
Use an exposure time of 1.35 seconds with the standard RECON-QHY system.
Expected flux drop is 53% with SNR of 10.0 per integration
Apparent velocity is 10.0 km/sec on the sky relative to the star, or, 10.5 arcsec/hr.
The recommended exposure time corresponds to 13.6 km per image.
The 1-sigma error in the time of the event is 2.5 seconds.
The 1-sigma cross-track error in the shadow position is 35.3 km.
The sky-plane scale is 3436.4 km/arcsec.
Diameter estimates:
70.2 km assuming a 5% albedo, aximum of 7.0 sec for a central chord
28.6 km assuming a 30% albedo, maximum of 2.9 sec for a central chord
Cross-track diameter of 70.2 km used for deployment plan.
Star training set for 9799_Thronium, (2025/03/21 22:38UT) Object RA Dec mag sep mel Sirius 06:46:15.5 -16:45:08 -1.5 22.09 132 15Rho Pup 08:08:37.1 -24:22:42 2.8 13.05 116 PPM 219933 08:19:35.7 -12:43:09 6.1 1.77 124 PPM 219865 08:16:36.8 -11:22:17 8.2 0.47 125 PPM 219810 08:14:04.2 -11:10:20 9.1 0.28 126 9799_Thronium 08:14:42.9 -11:24:25 15.1 125 Positions are for equinox of date
Star training set for 9799_Thronium, (2025/03/21 22:38UT) Object RA Dec mag sep mel Sirius 06:45:07.9 -16:43:28 -1.5 22.09 132 15Rho Pup 08:07:32.5 -24:18:14 2.8 13.05 116 PPM 219933 08:18:24.4 -12:38:20 6.1 1.77 124 PPM 219865 08:15:24.8 -11:17:34 8.2 0.47 125 PPM 219810 08:12:52.2 -11:05:42 9.1 0.28 126 9799_Thronium 08:13:31.0 -11:19:46 15.1 125 Positions are for J2000