Occultation event with (7641) Cteatus, event index number 1005
Regions able to see the event: Australia
Geocentric closest approach at 2025/05/27 11:37:36 UTC
J2000 position of star is 08:11:58.9 -12:53:38
Equinox of date position of star is 08:13:10.5 -12:58:16
Star is 66 degrees from the moon. Moon is 0% illuminated.
Stellar brightness G=15.1, 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 7.0 per integration for unocculted signal
Expected flux drop is 49% with SNR of 3.5 for the occulted depth (per occulted point)
Apparent velocity is 28.5 km/sec on the sky relative to the star, or, 26.9 arcsec/hr.
Position angle of asteroid motion is 4.4 degrees
The recommended exposure time corresponds to 18.6 km per image.
The 1-sigma error in the time of the event is 1.4 seconds.
The 1-sigma cross-track error in the shadow position is 21.6 km.
The sky-plane scale is 3824.3 km/arcsec.
Diameter estimates:
76.2 km assuming a 5% albedo, aximum of 2.7 sec for a central chord
31.1 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 76.2 km used for deployment plan.
Star training set for 7641_Cteatus, (2025/05/27 11:38UT) Object RA Dec mag sep mel Sirius 06:46:16.0 -16:45:09 -1.5 21.33 54 15Rho Pup 08:08:37.6 -24:22:44 2.8 11.46 72 18 Pup 08:11:50.5 -13:52:32 5.7 0.96 66 PPM 219819 08:14:18.7 -12:47:50 8.0 0.33 66 PPM 219782 08:12:59.9 -12:45:22 9.0 0.22 66 7641_Cteatus 08:13:10.5 -12:58:16 15.1 66 Positions are for equinox of date
Star training set for 7641_Cteatus, (2025/05/27 11:38UT) Object RA Dec mag sep mel Sirius 06:45:07.9 -16:43:28 -1.5 21.33 54 15Rho Pup 08:07:32.5 -24:18:14 2.8 11.46 72 18 Pup 08:10:39.4 -13:47:56 5.7 0.96 66 PPM 219819 08:13:07.0 -12:43:10 8.0 0.33 66 PPM 219782 08:11:48.2 -12:40:44 9.0 0.22 66 7641_Cteatus 08:11:58.9 -12:53:38 15.1 66 Positions are for J2000