Occultation event with (12242) Koon, event index number 4893
Regions able to see the event: Australia
Geocentric closest approach at 2026/11/26 19:22:07 UTC
J2000 position of star is 06:08:29.1 -02:33:06
Equinox of date position of star is 06:09:50.3 -02:33:28
Star is 30 degrees from the moon. Moon is 93% illuminated.
Stellar brightness G=16.4, apparent brightess of occulting body is G=16.1
Use an exposure time of 0.85 seconds with the standard RECON-QHY system.
SNR of 3.1 per integration for unocculted signal
Expected flux drop is 45% with SNR of 1.4 for the occulted depth (per occulted point)
Apparent velocity is 18.0 km/sec on the sky relative to the star, or, 19.7 arcsec/hr.
Position angle of asteroid motion is 57.0 degrees
The recommended exposure time corresponds to 15.3 km per image.
The 1-sigma error in the time of the event is 0.4 seconds.
The 1-sigma cross-track error in the shadow position is 32.3 km.
The sky-plane scale is 3281.3 km/arcsec.
Diameter estimates:
39.8 km assuming a 5% albedo, maximum of 2.2 sec for a central chord
16.2 km assuming a 30% albedo, maximum of 0.9 sec for a central chord
Cross-track diameter of 37.9 km used for deployment plan.
Star training set for 12242_Koon, (2026/11/26 19:22UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.8 +07:24:35 0.4 10.50 21 Saiph 05:49:02.0 -09:39:44 2.1 8.79 38 PPM 188806 06:07:58.8 -04:11:55 5.4 1.71 32 PPM 176136 06:10:18.2 -02:02:37 7.9 0.53 29 PPM 176133 06:10:04.1 -02:30:27 8.7 0.08 30 12242_Koon 06:09:50.3 -02:33:28 16.1 30 Positions are for equinox of date
Star training set for 12242_Koon, (2026/11/26 19:22UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 10.50 21 Saiph 05:47:45.4 -09:40:11 2.1 8.79 38 PPM 188806 06:06:38.7 -04:11:38 5.4 1.71 32 PPM 176136 06:08:56.7 -02:02:14 7.9 0.53 29 PPM 176133 06:08:43.0 -02:30:05 8.7 0.08 30 12242_Koon 06:08:29.1 -02:33:06 16.1 30 Positions are for J2000