Occultation event with (1208) Troilus, event index number 4076
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/08/22 09:12:17 UTC
J2000 position of star is 05:25:48.2 +37:23:11
Equinox of date position of star is 05:27:37.1 +37:24:28
Star is 171 degrees from the moon. Moon is 71% illuminated.
Stellar brightness G=16.5, apparent brightess of occulting body is G=14.8
Use an exposure time of 1.25 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 18% with SNR of 0.5 for the occulted depth (per occulted point)
Apparent velocity is 26.1 km/sec on the sky relative to the star, or, 23.4 arcsec/hr.
Position angle of asteroid motion is 57.4 degrees
The recommended exposure time corresponds to 32.6 km per image.
The 1-sigma error in the time of the event is 1.2 seconds.
The 1-sigma cross-track error in the shadow position is 14.6 km.
The sky-plane scale is 4015.6 km/arcsec.
Diameter estimates:
92.9 km assuming a 5% albedo, maximum of 3.6 sec for a central chord
37.9 km assuming a 30% albedo, maximum of 1.5 sec for a central chord
Cross-track diameter of 100.5 km used for deployment plan.
Star training set for 1208_Troilus, (2026/08/22 09:12UT) Object RA Dec mag sep mel Aldebaran 04:37:27.1 +16:33:38 0.8 23.60 162 3Iot Aur 04:58:44.0 +33:12:20 2.7 7.23 171 21Sig Aur 05:26:28.0 +37:24:27 6.4 0.23 171 PPM 070318 05:26:46.9 +37:31:30 8.6 0.20 170 PPM 070344 05:27:54.4 +37:22:41 10.5 0.06 171 1208_Troilus 05:27:37.1 +37:24:28 14.8 171 Positions are for equinox of date
Star training set for 1208_Troilus, (2026/08/22 09:12UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 23.60 162 3Iot Aur 04:56:59.6 +33:09:57 2.7 7.23 171 21Sig Aur 05:24:39.2 +37:23:07 6.4 0.23 171 PPM 070318 05:24:58.0 +37:30:11 8.6 0.20 170 PPM 070344 05:26:05.6 +37:21:25 10.5 0.06 171 1208_Troilus 05:25:48.2 +37:23:11 14.8 171 Positions are for J2000