Occultation event with (12242) Koon, event index number 4579
Regions able to see the event: SAmericaN,SAmericaS
Geocentric closest approach at 2026/11/06 08:07:50 UTC
J2000 position of star is 06:15:26.8 -00:51:24
Equinox of date position of star is 06:16:48.9 -00:52:01
Star is 93 degrees from the moon. Moon is 9% illuminated.
Stellar brightness G=15.7, apparent brightess of occulting body is G=16.3
Use an exposure time of 0.60 seconds with the standard RECON-QHY system.
SNR of 4.5 per integration for unocculted signal
Expected flux drop is 65% with SNR of 2.9 for the occulted depth (per occulted point)
Apparent velocity is 15.3 km/sec on the sky relative to the star, or, 16.1 arcsec/hr.
Position angle of asteroid motion is 31.6 degrees
The recommended exposure time corresponds to 9.2 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 25.8 km.
The sky-plane scale is 3407.3 km/arcsec.
Diameter estimates:
39.8 km assuming a 5% albedo, maximum of 2.6 sec for a central chord
16.2 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 37.9 km used for deployment plan.
Star training set for 12242_Koon, (2026/11/06 08:08UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.6 +07:24:35 0.4 9.69 99 34Del Ori 05:33:22.8 -00:16:53 2.2 10.87 104 PPM 176187 06:16:56.2 -00:31:28 6.2 0.34 93 PPM 176180 06:16:08.6 -01:04:14 10.5 0.26 93 12242_Koon 06:16:48.9 -00:52:01 16.3 93 Positions are for equinox of date
Star training set for 12242_Koon, (2026/11/06 08:08UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 9.69 99 34Del Ori 05:32:00.4 -00:17:57 2.2 10.87 104 PPM 176187 06:15:34.0 -00:30:50 6.2 0.34 93 PPM 176180 06:14:46.7 -01:03:38 10.5 0.26 93 12242_Koon 06:15:26.8 -00:51:24 16.3 93 Positions are for J2000