Occultation event with (12242) Koon, event index number 4705
Regions able to see the event: Australia
Geocentric closest approach at 2026/11/15 14:24:52 UTC
J2000 position of star is 06:12:51.2 -01:40:27
Equinox of date position of star is 06:14:12.8 -01:40:59
Star is 141 degrees from the moon. Moon is 32% illuminated.
Stellar brightness G=16.3, apparent brightess of occulting body is G=16.2
Use an exposure time of 0.80 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 47% with SNR of 1.4 for the occulted depth (per occulted point)
Apparent velocity is 16.5 km/sec on the sky relative to the star, or, 17.8 arcsec/hr.
Position angle of asteroid motion is 44.6 degrees
The recommended exposure time corresponds to 13.2 km per image.
The 1-sigma error in the time of the event is 0.9 seconds.
The 1-sigma cross-track error in the shadow position is 30.1 km.
The sky-plane scale is 3342.0 km/arcsec.
Diameter estimates:
39.8 km assuming a 5% albedo, maximum of 2.4 sec for a central chord
16.2 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 37.9 km used for deployment plan.
Star training set for 12242_Koon, (2026/11/15 14:25UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.7 +07:24:35 0.4 10.10 142 Saiph 05:49:01.9 -09:39:44 2.1 10.14 131 PPM 176187 06:16:56.3 -00:31:28 6.2 1.34 142 PPM 176172 06:14:58.1 -01:49:56 8.3 0.24 141 PPM 176165 06:14:09.8 -01:39:00 9.7 0.04 141 12242_Koon 06:14:12.8 -01:40:59 16.2 141 Positions are for equinox of date
Star training set for 12242_Koon, (2026/11/15 14:25UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 10.10 142 Saiph 05:47:45.4 -09:40:11 2.1 10.14 131 PPM 176187 06:15:34.0 -00:30:50 6.2 1.34 142 PPM 176172 06:13:36.6 -01:49:22 8.3 0.24 141 PPM 176165 06:12:48.2 -01:38:28 9.7 0.04 141 12242_Koon 06:12:51.2 -01:40:27 16.2 141 Positions are for J2000