Occultation event with (11552) Boucolion, event index number 4251
Regions able to see the event: Europe
Geocentric closest approach at 2026/09/17 02:51:55 UTC
J2000 position of star is 06:38:13.9 +12:20:52
Equinox of date position of star is 06:39:43.7 +12:19:22
Star is 142 degrees from the moon. Moon is 34% illuminated.
Stellar brightness G=15.4, apparent brightess of occulting body is G=16.2
Use an exposure time of 0.65 seconds with the standard RECON-QHY system.
SNR of 5.9 per integration for unocculted signal
Expected flux drop is 67% with SNR of 4.0 for the occulted depth (per occulted point)
Apparent velocity is 19.0 km/sec on the sky relative to the star, or, 16.0 arcsec/hr.
Position angle of asteroid motion is 103.0 degrees
The recommended exposure time corresponds to 12.3 km per image.
The 1-sigma error in the time of the event is 0.2 seconds.
The 1-sigma cross-track error in the shadow position is 30.7 km.
The sky-plane scale is 4261.0 km/arcsec.
Diameter estimates:
57.3 km assuming a 5% albedo, maximum of 3.0 sec for a central chord
23.4 km assuming a 30% albedo, maximum of 1.2 sec for a central chord
Cross-track diameter of 51.1 km used for deployment plan.
Star training set for 11552_Boucolion, (2026/09/17 02:52UT) Object RA Dec mag sep mel Betelgeuse 05:56:37.1 +07:24:35 0.4 11.70 148 Alhena 06:39:15.3 +16:22:27 1.9 4.05 144 30 Gem 06:45:29.6 +13:11:56 5.8 1.66 141 PPM 122797 06:40:03.1 +12:42:46 7.9 0.40 142 PPM 122817 06:40:53.6 +12:04:51 9.6 0.37 142 PPM 122810 06:40:33.1 +12:27:44 10.9 0.24 142 11552_Boucolio 06:39:43.7 +12:19:22 16.2 142 Positions are for equinox of date
Star training set for 11552_Boucolion, (2026/09/17 02:52UT) Object RA Dec mag sep mel Betelgeuse 05:55:10.3 +07:24:26 0.4 11.70 148 Alhena 06:37:42.8 +16:23:56 1.9 4.05 144 30 Gem 06:43:59.3 +13:13:39 5.8 1.66 141 PPM 122797 06:38:33.0 +12:44:18 7.9 0.40 142 PPM 122817 06:39:23.9 +12:06:25 9.6 0.37 142 PPM 122810 06:39:03.2 +12:29:17 10.9 0.24 142 11552_Boucolio 06:38:13.9 +12:20:52 16.2 142 Positions are for J2000