Occultation event with (7641) Cteatus, event index number 3822
Regions able to see the event: Senegal
Geocentric closest approach at 2026/07/01 20:40:44 UTC
J2000 position of star is 10:38:34.1 -23:16:20
Equinox of date position of star is 10:39:50.3 -23:24:38
Star is 122 degrees from the moon. Moon is 97% illuminated.
Stellar brightness G=15.8, apparent brightess of occulting body is G=15.1
Use an exposure time of 0.65 seconds with the standard RECON-QHY system.
SNR of 3.8 per integration for unocculted signal
Expected flux drop is 34% with SNR of 1.3 for the occulted depth (per occulted point)
Apparent velocity is 27.6 km/sec on the sky relative to the star, or, 25.9 arcsec/hr.
Position angle of asteroid motion is 79.4 degrees
The recommended exposure time corresponds to 17.9 km per image.
The 1-sigma error in the time of the event is 0.1 seconds.
The 1-sigma cross-track error in the shadow position is 46.0 km.
The sky-plane scale is 3826.7 km/arcsec.
Diameter estimates:
76.6 km assuming a 5% albedo, maximum of 2.8 sec for a central chord
31.3 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 71.8 km used for deployment plan.
Star training set for 7641_Cteatus, (2026/07/01 20:41UT) Object RA Dec mag sep mel Spica 13:26:35.6 -11:17:56 1.0 41.42 97 Alphard 09:28:53.4 -08:46:29 2.0 22.42 144 PPM 257864 10:36:13.6 -23:18:49 6.2 0.83 123 PPM 257923 10:38:51.8 -23:31:14 7.4 0.25 122 PPM 257934 10:39:18.3 -23:24:49 9.4 0.12 122 7641_Cteatus 10:39:50.3 -23:24:38 15.1 122 Positions are for equinox of date
Star training set for 7641_Cteatus, (2026/07/01 20:41UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 41.42 97 Alphard 09:27:35.2 -08:39:30 2.0 22.42 144 PPM 257864 10:34:57.5 -23:10:33 6.2 0.83 123 PPM 257923 10:37:35.7 -23:22:56 7.4 0.25 122 PPM 257934 10:38:02.2 -23:16:31 9.4 0.12 122 7641_Cteatus 10:38:34.1 -23:16:20 15.1 122 Positions are for J2000