Occultation event with (1208) Troilus, event index number 1170
Regions able to see the event: Australia
Geocentric closest approach at 2025/07/26 17:14:08 UTC
J2000 position of star is 03:31:52.0 +15:48:57
Equinox of date position of star is 03:33:18.4 +15:54:05
Star is 94 degrees from the moon. Moon is 4% illuminated.
Stellar brightness G=16.5, apparent brightess of occulting body is G=14.6
Use an exposure time of 1.30 seconds with the standard RECON-QHY system.
SNR of 3.0 per integration for unocculted signal
Expected flux drop is 15% with SNR of 0.5 for the occulted depth (per occulted point)
Apparent velocity is 22.1 km/sec on the sky relative to the star, or, 21.0 arcsec/hr.
The recommended exposure time corresponds to 28.8 km per image.
The 1-sigma error in the time of the event is 1.7 seconds.
The 1-sigma cross-track error in the shadow position is 40.7 km.
The sky-plane scale is 3793.9 km/arcsec.
Diameter estimates:
92.9 km assuming a 5% albedo, aximum of 4.2 sec for a central chord
37.9 km assuming a 30% albedo, maximum of 1.7 sec for a central chord
Cross-track diameter of 92.9 km used for deployment plan.
Star training set for 1208_Troilus, (2025/07/26 17:14UT) Object RA Dec mag sep mel Aldebaran 04:37:23.4 +16:33:31 0.8 15.39 78 Menkar 03:03:37.1 +04:11:19 2.5 13.80 104 PPM 119236 03:39:14.2 +15:30:45 6.4 1.48 92 PPM 119118 03:30:46.2 +16:17:05 8.5 0.72 94 PPM 119164 03:34:20.0 +15:38:06 8.6 0.36 93 1208_Troilus 03:33:18.4 +15:54:05 14.6 93 Positions are for equinox of date
Star training set for 1208_Troilus, (2025/07/26 17:14UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 15.39 78 Menkar 03:02:16.8 +04:05:21 2.5 13.80 104 PPM 119236 03:37:47.9 +15:25:49 6.4 1.48 92 PPM 119118 03:29:19.6 +16:11:53 8.5 0.72 94 PPM 119164 03:32:53.7 +15:33:01 8.6 0.36 93 1208_Troilus 03:31:52.0 +15:48:57 14.6 94 Positions are for J2000