Occultation event with (1208) Troilus, event index number 4286
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/09/22 07:18:17 UTC
J2000 position of star is 05:41:06.1 +40:09:04
Equinox of date position of star is 05:42:58.4 +40:09:46
Star is 137 degrees from the moon. Moon is 81% illuminated.
Stellar brightness G=15.5, apparent brightess of occulting body is G=14.7
Use an exposure time of 1.45 seconds with the standard RECON-QHY system.
SNR of 8.0 per integration for unocculted signal
Expected flux drop is 33% with SNR of 2.6 for the occulted depth (per occulted point)
Apparent velocity is 17.1 km/sec on the sky relative to the star, or, 16.6 arcsec/hr.
Position angle of asteroid motion is 31.0 degrees
The recommended exposure time corresponds to 24.7 km per image.
The 1-sigma error in the time of the event is 2.0 seconds.
The 1-sigma cross-track error in the shadow position is 1.6 km.
The sky-plane scale is 3698.4 km/arcsec.
Diameter estimates:
92.9 km assuming a 5% albedo, maximum of 5.4 sec for a central chord
37.9 km assuming a 30% albedo, maximum of 2.2 sec for a central chord
Cross-track diameter of 100.5 km used for deployment plan.
Star training set for 1208_Troilus, (2026/09/22 07:18UT) Object RA Dec mag sep mel Aldebaran 04:37:27.4 +16:33:39 0.8 27.55 122 34Bet Aur 06:01:29.4 +44:56:50 1.9 5.87 139 32Nu Aur 05:53:20.6 +39:09:12 4.0 2.24 139 PPM 070699 05:42:24.1 +39:50:46 8.0 0.34 137 PPM 048355 05:43:02.4 +40:10:59 9.7 0.02 137 1208_Troilus 05:42:58.4 +40:09:46 14.7 138 Positions are for equinox of date
Star training set for 1208_Troilus, (2026/09/22 07:18UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 27.55 122 34Bet Aur 05:59:31.6 +44:56:51 1.9 5.87 139 32Nu Aur 05:51:29.4 +39:08:55 4.0 2.24 139 PPM 070699 05:40:32.2 +39:50:03 8.0 0.34 137 PPM 048355 05:41:10.2 +40:10:17 9.7 0.02 137 1208_Troilus 05:41:06.1 +40:09:04 14.7 137 Positions are for J2000