Occultation event with (7641) Cteatus, event index number 941
Regions able to see the event: Australia
Geocentric closest approach at 2025/05/02 14:11:30 UTC
J2000 position of star is 07:56:17.4 -13:54:40
Equinox of date position of star is 07:57:28.0 -13:58:48
Star is 42 degrees from the moon. Moon is 30% illuminated.
Stellar brightness G=14.9, apparent brightess of occulting body is G=15.0
Use an exposure time of 0.85 seconds with the standard RECON-QHY system.
SNR of 9.9 per integration for unocculted signal
Expected flux drop is 52% with SNR of 5.2 for the occulted depth (per occulted point)
Apparent velocity is 20.8 km/sec on the sky relative to the star, or, 20.7 arcsec/hr.
Position angle of asteroid motion is 17.5 degrees
The recommended exposure time corresponds to 17.7 km per image.
The 1-sigma error in the time of the event is 1.8 seconds.
The 1-sigma cross-track error in the shadow position is 23.1 km.
The sky-plane scale is 3603.0 km/arcsec.
Diameter estimates:
76.2 km assuming a 5% albedo, aximum of 3.7 sec for a central chord
31.1 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 76.2 km used for deployment plan.
Star training set for 7641_Cteatus, (2025/05/02 14:11UT) Object RA Dec mag sep mel Sirius 06:46:15.8 -16:45:09 -1.5 17.38 45 15Rho Pup 08:08:37.4 -24:22:43 2.8 10.73 53 9 Pup 07:52:56.7 -13:58:00 5.2 1.10 42 PPM 219476 08:00:13.3 -13:58:02 8.4 0.67 42 PPM 219429 07:58:18.7 -14:02:04 9.2 0.21 42 7641_Cteatus 07:57:28.0 -13:58:48 15.0 42 Positions are for equinox of date
Star training set for 7641_Cteatus, (2025/05/02 14:11UT) Object RA Dec mag sep mel Sirius 06:45:07.9 -16:43:28 -1.5 17.38 45 15Rho Pup 08:07:32.5 -24:18:14 2.8 10.73 53 9 Pup 07:51:46.2 -13:54:01 5.2 1.10 42 PPM 219476 07:59:02.7 -13:53:49 8.4 0.67 42 PPM 219429 07:57:08.2 -13:57:54 9.2 0.21 42 7641_Cteatus 07:56:17.4 -13:54:40 15.0 42 Positions are for J2000