Occultation event with (12242) Koon, event index number 3232
Regions able to see the event: US
Geocentric closest approach at 2026/02/10 07:01:15 UTC
J2000 position of star is 03:37:55.5 +06:31:00
Equinox of date position of star is 03:39:19.1 +06:36:03
Star is 161 degrees from the moon. Moon is 43% illuminated.
Stellar brightness G=15.9, apparent brightess of occulting body is G=16.5
Use an exposure time of 0.95 seconds with the standard RECON-QHY system.
SNR of 5.0 per integration for unocculted signal
Expected flux drop is 63% with SNR of 3.2 for the occulted depth (per occulted point)
Apparent velocity is 9.5 km/sec on the sky relative to the star, or, 9.3 arcsec/hr.
Position angle of asteroid motion is 75.4 degrees
The recommended exposure time corresponds to 9.0 km per image.
The 1-sigma error in the time of the event is 0.1 seconds.
The 1-sigma cross-track error in the shadow position is 31.6 km.
The sky-plane scale is 3680.9 km/arcsec.
Diameter estimates:
39.8 km assuming a 5% albedo, maximum of 4.2 sec for a central chord
16.2 km assuming a 30% albedo, maximum of 1.7 sec for a central chord
Cross-track diameter of 37.9 km used for deployment plan.
Star training set for 12242_Koon, (2026/02/10 07:01UT) Object RA Dec mag sep mel Aldebaran 04:37:25.3 +16:33:35 0.8 17.35 165 Menkar 03:03:38.9 +04:11:26 2.5 9.20 156 29 Tau 03:47:03.9 +06:07:48 5.3 1.98 161 PPM 146798 03:41:43.1 +06:37:44 8.2 0.60 161 PPM 146786 03:41:04.9 +06:32:55 9.0 0.44 161 PPM 146739 03:38:58.9 +06:27:52 11.3 0.16 161 12242_Koon 03:39:19.1 +06:36:03 16.5 161 Positions are for equinox of date
Star training set for 12242_Koon, (2026/02/10 07:01UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 17.35 165 Menkar 03:02:16.8 +04:05:21 2.5 9.20 156 29 Tau 03:45:40.5 +06:03:00 5.3 1.98 161 PPM 146798 03:40:19.5 +06:32:46 8.2 0.60 161 PPM 146786 03:39:41.3 +06:27:55 9.0 0.44 161 PPM 146739 03:37:35.4 +06:22:49 11.3 0.16 161 12242_Koon 03:37:55.5 +06:31:00 16.5 161 Positions are for J2000