Occultation event with (7641) Cteatus, event index number 3779
Regions able to see the event: SAfrica
Geocentric closest approach at 2026/06/04 17:54:41 UTC
J2000 position of star is 10:21:20.4 -24:44:28
Equinox of date position of star is 10:22:34.9 -24:52:30
Star is 125 degrees from the moon. Moon is 84% illuminated.
Stellar brightness G=16.7, apparent brightess of occulting body is G=15.0
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 17% with SNR of 0.5 for the occulted depth (per occulted point)
Apparent velocity is 20.8 km/sec on the sky relative to the star, or, 21.0 arcsec/hr.
Position angle of asteroid motion is 56.8 degrees
The recommended exposure time corresponds to 31.2 km per image.
The 1-sigma error in the time of the event is 0.6 seconds.
The 1-sigma cross-track error in the shadow position is 42.9 km.
The sky-plane scale is 3566.9 km/arcsec.
Diameter estimates:
76.6 km assuming a 5% albedo, maximum of 3.7 sec for a central chord
31.3 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 71.8 km used for deployment plan.
Star training set for 7641_Cteatus, (2026/06/04 17:55UT) Object RA Dec mag sep mel Bet Cru 12:49:17.1 -59:49:58 1.3 43.17 82 Alphard 09:28:53.2 -08:46:28 2.0 20.56 145 PPM 257554 10:22:43.4 -23:50:41 6.5 1.03 125 PPM 257595 10:24:14.1 -24:28:05 7.1 0.55 125 PPM 257531 10:21:32.8 -24:58:03 10.0 0.25 125 7641_Cteatus 10:22:34.9 -24:52:30 15.0 124 Positions are for equinox of date
Star training set for 7641_Cteatus, (2026/06/04 17:55UT) Object RA Dec mag sep mel Bet Cru 12:47:43.1 -59:41:20 1.3 43.17 82 Alphard 09:27:35.2 -08:39:30 2.0 20.56 145 PPM 257554 10:21:28.6 -23:42:39 6.5 1.03 125 PPM 257595 10:22:59.4 -24:20:02 7.1 0.55 125 PPM 257531 10:20:18.4 -24:50:02 10.0 0.25 125 7641_Cteatus 10:21:20.4 -24:44:28 15.0 125 Positions are for J2000