Occultation event with (3793) Leonteus, event index number 1692
Regions able to see the event: SAfrica
Geocentric closest approach at 2025/12/18 00:46:18 UTC
J2000 position of star is 12:42:01.8 -11:12:18
Equinox of date position of star is 12:43:22.9 -11:20:50
Star is 50 degrees from the moon. Moon is 4% illuminated.
Stellar brightness G=16.6, apparent brightess of occulting body is G=14.4
Use an exposure time of 1.50 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 13% with SNR of 0.4 for the occulted depth (per occulted point)
Apparent velocity is 21.3 km/sec on the sky relative to the star, or, 19.9 arcsec/hr.
Position angle of asteroid motion is 108.6 degrees
The recommended exposure time corresponds to 32.0 km per image.
The 1-sigma error in the time of the event is 0.7 seconds.
The 1-sigma cross-track error in the shadow position is 39.4 km.
The sky-plane scale is 3850.4 km/arcsec.
Diameter estimates:
104.7 km assuming a 5% albedo, aximum of 4.9 sec for a central chord
42.8 km assuming a 30% albedo, maximum of 2.0 sec for a central chord
Cross-track diameter of 112.0 km used for deployment plan.
Star training set for 3793_Leonteus, (2025/12/18 00:46UT) Object RA Dec mag sep mel Spica 13:26:33.9 -11:17:46 1.0 10.59 40 4Gam Crv 12:17:08.7 -17:41:09 2.6 8.97 53 PPM 226198 12:42:36.9 -13:09:22 6.0 1.82 49 PPM 226295 12:46:25.5 -11:08:27 8.2 0.77 49 PPM 226217 12:43:32.4 -11:19:39 8.9 0.04 50 3793_Leonteus 12:43:22.9 -11:20:50 14.4 49 Positions are for equinox of date
Star training set for 3793_Leonteus, (2025/12/18 00:46UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 10.59 40 4Gam Crv 12:15:48.1 -17:32:30 2.6 8.97 53 PPM 226198 12:41:15.6 -13:00:51 6.0 1.82 49 PPM 226295 12:45:04.3 -10:59:57 8.2 0.77 49 PPM 226217 12:42:11.3 -11:11:07 8.9 0.04 50 3793_Leonteus 12:42:01.8 -11:12:18 14.4 50 Positions are for J2000