Occultation event with (1208) Troilus, event index number 4036
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/08/17 09:20:00 UTC
J2000 position of star is 05:22:23.3 +36:58:12
Equinox of date position of star is 05:24:11.6 +36:59:37
Star is 121 degrees from the moon. Moon is 24% illuminated.
Stellar brightness G=16.7, apparent brightess of occulting body is G=14.8
Use an exposure time of 1.65 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 27.7 km/sec on the sky relative to the star, or, 24.5 arcsec/hr.
Position angle of asteroid motion is 59.6 degrees
The recommended exposure time corresponds to 45.6 km per image.
The 1-sigma error in the time of the event is 1.1 seconds.
The 1-sigma cross-track error in the shadow position is 15.7 km.
The sky-plane scale is 4063.1 km/arcsec.
Diameter estimates:
92.9 km assuming a 5% albedo, maximum of 3.4 sec for a central chord
37.9 km assuming a 30% albedo, maximum of 1.4 sec for a central chord
Cross-track diameter of 100.5 km used for deployment plan.
Star training set for 1208_Troilus, (2026/08/17 09:20UT) Object RA Dec mag sep mel Aldebaran 04:37:27.1 +16:33:38 0.8 22.90 133 3Iot Aur 04:58:43.9 +33:12:20 2.7 6.44 127 21Sig Aur 05:26:28.0 +37:24:27 6.4 0.61 121 PPM 070289 05:25:31.6 +37:12:42 8.3 0.34 121 PPM 070261 05:24:04.1 +37:04:06 9.8 0.08 121 1208_Troilus 05:24:11.6 +36:59:37 14.8 121 Positions are for equinox of date
Star training set for 1208_Troilus, (2026/08/17 09:20UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 22.90 133 3Iot Aur 04:56:59.6 +33:09:57 2.7 6.44 127 21Sig Aur 05:24:39.2 +37:23:07 6.4 0.61 121 PPM 070289 05:23:43.0 +37:11:20 8.3 0.34 121 PPM 070261 05:22:15.7 +37:02:41 9.8 0.08 121 1208_Troilus 05:22:23.3 +36:58:12 14.8 121 Positions are for J2000