Occultation event with (12242) Koon, event index number 1112
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/07/06 08:02:22 UTC
J2000 position of star is 03:42:03.6 +16:31:39
Equinox of date position of star is 03:43:30.5 +16:36:27
Star is 171 degrees from the moon. Moon is 81% illuminated.
Stellar brightness G=13.9, apparent brightess of occulting body is G=16.6
Use an exposure time of 0.25 seconds with the standard RECON-QHY system.
SNR of 9.9 per integration for unocculted signal
Expected flux drop is 93% with SNR of 9.2 for the occulted depth (per occulted point)
Apparent velocity is 32.1 km/sec on the sky relative to the star, or, 27.8 arcsec/hr.
The recommended exposure time corresponds to 8.0 km per image.
The 1-sigma error in the time of the event is 1.7 seconds.
The 1-sigma cross-track error in the shadow position is 16.1 km.
The sky-plane scale is 4160.7 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, (2025/07/06 08:02UT) Object RA Dec mag sep mel Aldebaran 04:37:23.3 +16:33:30 0.8 12.91 160 44Zet Per 03:55:44.5 +31:57:26 2.8 15.60 168 PPM 119253 03:40:52.6 +16:37:04 6.2 0.63 172 PPM 119306 03:44:48.2 +16:29:58 8.1 0.33 171 12242_Koon 03:43:30.5 +16:36:27 16.6 171 Positions are for equinox of date
Star training set for 12242_Koon, (2025/07/06 08:02UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 12.91 160 44Zet Per 03:54:07.9 +31:53:01 2.8 15.60 168 PPM 119253 03:39:25.8 +16:32:11 6.2 0.63 172 PPM 119306 03:43:21.4 +16:25:12 8.1 0.33 171 12242_Koon 03:42:03.6 +16:31:39 16.6 171 Positions are for J2000