Occultation event with (12242) Koon, event index number 1198
Regions able to see the event: SMexico
Geocentric closest approach at 2025/07/01 11:21:20 UTC
J2000 position of star is 03:38:14.6 +16:31:40
Equinox of date position of star is 03:39:41.3 +16:36:35
Star is 119 degrees from the moon. Moon is 37% illuminated.
Stellar brightness G=15.4, apparent brightess of occulting body is G=16.6
Use an exposure time of 0.30 seconds with the standard RECON-QHY system.
SNR of 3.3 per integration for unocculted signal
Expected flux drop is 75% with SNR of 2.5 for the occulted depth (per occulted point)
Apparent velocity is 33.4 km/sec on the sky relative to the star, or, 28.7 arcsec/hr.
The recommended exposure time corresponds to 10.0 km per image.
The 1-sigma error in the time of the event is 1.6 seconds.
The 1-sigma cross-track error in the shadow position is 15.6 km.
The sky-plane scale is 4197.9 km/arcsec.
Diameter estimates:
39.8 km assuming a 5% albedo, aximum of 1.2 sec for a central chord
16.2 km assuming a 30% albedo, maximum of 0.5 sec for a central chord
Cross-track diameter of 39.8 km used for deployment plan.
Star training set for 12242_Koon, (2025/07/01 11:21UT) Object RA Dec mag sep mel Aldebaran 04:37:23.2 +16:33:30 0.8 13.82 105 Menkar 03:03:36.9 +04:11:18 2.5 15.25 129 PPM 119253 03:40:52.5 +16:37:04 6.2 0.28 118 PPM 119244 03:40:00.7 +16:27:36 10.1 0.17 119 12242_Koon 03:39:41.3 +16:36:35 16.6 118 Positions are for equinox of date
Star training set for 12242_Koon, (2025/07/01 11:21UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 13.82 105 Menkar 03:02:16.8 +04:05:21 2.5 15.25 129 PPM 119253 03:39:25.8 +16:32:11 6.2 0.28 118 PPM 119244 03:38:34.1 +16:22:41 10.1 0.17 119 12242_Koon 03:38:14.6 +16:31:40 16.6 119 Positions are for J2000