Occultation event with (7641) Cteatus, event index number 3840
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/07/11 21:41:27 UTC
J2000 position of star is 10:46:18.6 -23:02:00
Equinox of date position of star is 10:47:35.4 -23:10:25
Star is 100 degrees from the moon. Moon is 9% illuminated.
Stellar brightness G=16.5, apparent brightess of occulting body is G=15.2
Use an exposure time of 1.10 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 23% with SNR of 0.7 for the occulted depth (per occulted point)
Apparent velocity is 30.2 km/sec on the sky relative to the star, or, 27.7 arcsec/hr.
Position angle of asteroid motion is 85.1 degrees
The recommended exposure time corresponds to 33.2 km per image.
The 1-sigma error in the time of the event is 0.2 seconds.
The 1-sigma cross-track error in the shadow position is 45.1 km.
The sky-plane scale is 3919.2 km/arcsec.
Diameter estimates:
76.6 km assuming a 5% albedo, maximum of 2.5 sec for a central chord
31.3 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 71.8 km used for deployment plan.
Star training set for 7641_Cteatus, (2026/07/11 21:41UT) Object RA Dec mag sep mel Spica 13:26:35.7 -11:17:56 1.0 39.63 130 4Gam Crv 12:17:10.5 -17:41:21 2.6 21.66 117 PPM 257864 10:36:13.6 -23:18:49 6.2 2.61 98 PPM 258116 10:47:25.2 -23:34:22 8.0 0.40 100 PPM 258122 10:47:38.1 -23:01:35 9.4 0.15 100 7641_Cteatus 10:47:35.4 -23:10:25 15.2 100 Positions are for equinox of date
Star training set for 7641_Cteatus, (2026/07/11 21:41UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 39.63 130 4Gam Crv 12:15:48.1 -17:32:30 2.6 21.66 117 PPM 257864 10:34:57.5 -23:10:33 6.2 2.61 98 PPM 258116 10:46:08.5 -23:25:58 8.0 0.40 100 PPM 258122 10:46:21.2 -22:53:10 9.4 0.15 100 7641_Cteatus 10:46:18.6 -23:02:00 15.2 100 Positions are for J2000