Occultation event with (7641) Cteatus, event index number 3140
Regions able to see the event: SAfrica
Geocentric closest approach at 2026/01/13 02:25:40 UTC
J2000 position of star is 10:49:20.6 -33:20:04
Equinox of date position of star is 10:50:33.8 -33:28:22
Star is 56 degrees from the moon. Moon is 28% illuminated.
Stellar brightness G=15.7, apparent brightess of occulting body is G=14.8
Use an exposure time of 1.35 seconds with the standard RECON-QHY system.
SNR of 6.2 per integration for unocculted signal
Expected flux drop is 30% with SNR of 1.8 for the occulted depth (per occulted point)
Apparent velocity is 13.2 km/sec on the sky relative to the star, or, 14.1 arcsec/hr.
Position angle of asteroid motion is 25.4 degrees
The recommended exposure time corresponds to 17.8 km per image.
The 1-sigma error in the time of the event is 2.7 seconds.
The 1-sigma cross-track error in the shadow position is 28.5 km.
The sky-plane scale is 3357.0 km/arcsec.
Diameter estimates:
76.6 km assuming a 5% albedo, maximum of 5.8 sec for a central chord
31.3 km assuming a 30% albedo, maximum of 2.4 sec for a central chord
Cross-track diameter of 71.8 km used for deployment plan.
Star training set for 7641_Cteatus, (2026/01/13 02:26UT) Object RA Dec mag sep mel Bet Cru 12:49:15.7 -59:49:50 1.3 32.75 44 Mu Vel 10:47:53.9 -49:33:29 2.8 16.09 57 PPM 288177 10:51:10.0 -34:11:48 5.5 0.73 56 PPM 288187 10:51:39.4 -33:58:41 7.4 0.55 56 PPM 288178 10:51:16.6 -33:24:46 9.1 0.16 56 7641_Cteatus 10:50:33.8 -33:28:22 14.8 56 Positions are for equinox of date
Star training set for 7641_Cteatus, (2026/01/13 02:26UT) Object RA Dec mag sep mel Bet Cru 12:47:43.1 -59:41:20 1.3 32.75 44 Mu Vel 10:46:46.5 -49:25:13 2.8 16.09 57 PPM 288177 10:49:57.0 -34:03:30 5.5 0.73 56 PPM 288187 10:50:26.3 -33:50:22 7.4 0.55 56 PPM 288178 10:50:03.4 -33:16:28 9.1 0.16 56 7641_Cteatus 10:49:20.6 -33:20:04 14.8 56 Positions are for J2000