Occultation event with (5123) Cynus, event index number 1688
Regions able to see the event: UAE
Geocentric closest approach at 2025/12/16 22:05:33 UTC
J2000 position of star is 12:06:44.3 +08:39:33
Equinox of date position of star is 12:08:03.9 +08:30:53
Star is 54 degrees from the moon. Moon is 9% illuminated.
Stellar brightness G=16.5, apparent brightess of occulting body is G=15.5
Use an exposure time of 1.00 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 29% with SNR of 0.9 for the occulted depth (per occulted point)
Apparent velocity is 15.5 km/sec on the sky relative to the star, or, 16.0 arcsec/hr.
Position angle of asteroid motion is 98.1 degrees
The recommended exposure time corresponds to 15.5 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 34.0 km.
The sky-plane scale is 3500.2 km/arcsec.
Diameter estimates:
57.5 km assuming a 5% albedo, aximum of 3.7 sec for a central chord
23.5 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 35.4 km used for deployment plan.
Star training set for 5123_Cynus, (2025/12/16 22:06UT) Object RA Dec mag sep mel Spica 13:26:33.9 -11:17:46 1.0 27.81 27 Denebola 11:50:22.9 +14:25:37 2.1 7.33 61 9Omi Vir 12:06:31.9 +08:35:20 4.1 0.39 55 PPM 158529 12:08:30.3 +09:31:06 8.1 1.01 55 9Omi Vir 12:06:31.9 +08:35:20 4.1 0.39 55 PPM 158512 12:07:15.3 +08:40:50 11.6 0.26 55 5123_Cynus 12:08:03.9 +08:30:53 15.5 54 Positions are for equinox of date
Star training set for 5123_Cynus, (2025/12/16 22:06UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 27.81 27 Denebola 11:49:02.7 +14:34:16 2.1 7.33 61 9Omi Vir 12:05:12.2 +08:44:00 4.1 0.39 55 PPM 158529 12:07:10.7 +09:39:46 8.1 1.01 55 9Omi Vir 12:05:12.2 +08:44:00 4.1 0.39 55 PPM 158512 12:05:55.7 +08:49:30 11.6 0.26 55 5123_Cynus 12:06:44.3 +08:39:33 15.5 54 Positions are for J2000