Occultation event with (1208) Troilus, event index number 4227
Regions able to see the event: Australia
Geocentric closest approach at 2026/09/12 19:25:51 UTC
J2000 position of star is 05:37:38.3 +39:15:57
Equinox of date position of star is 05:39:29.5 +39:16:47
Star is 106 degrees from the moon. Moon is 3% illuminated.
Stellar brightness G=16.1, apparent brightess of occulting body is G=14.7
Use an exposure time of 1.25 seconds with the standard RECON-QHY system.
SNR of 4.5 per integration for unocculted signal
Expected flux drop is 23% with SNR of 1.0 for the occulted depth (per occulted point)
Apparent velocity is 19.6 km/sec on the sky relative to the star, or, 18.5 arcsec/hr.
Position angle of asteroid motion is 42.2 degrees
The recommended exposure time corresponds to 24.4 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 7.4 km.
The sky-plane scale is 3797.9 km/arcsec.
Diameter estimates:
92.9 km assuming a 5% albedo, maximum of 4.8 sec for a central chord
37.9 km assuming a 30% albedo, maximum of 1.9 sec for a central chord
Cross-track diameter of 100.5 km used for deployment plan.
Star training set for 1208_Troilus, (2026/09/12 19:26UT) Object RA Dec mag sep mel Aldebaran 04:37:27.4 +16:33:39 0.8 26.44 120 34Bet Aur 06:01:29.3 +44:56:50 1.9 6.98 101 PPM 048174 05:32:42.0 +41:28:48 6.0 2.55 107 PPM 070709 05:42:57.0 +39:38:49 8.0 0.76 105 PPM 070643 05:40:06.0 +39:12:21 9.9 0.14 106 1208_Troilus 05:39:29.5 +39:16:47 14.7 105 Positions are for equinox of date
Star training set for 1208_Troilus, (2026/09/12 19:26UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 26.44 120 34Bet Aur 05:59:31.6 +44:56:51 1.9 6.98 101 PPM 048174 05:30:48.6 +41:27:42 6.0 2.55 107 PPM 070709 05:41:05.5 +39:38:07 8.0 0.76 105 PPM 070643 05:38:14.9 +39:11:33 9.9 0.14 106 1208_Troilus 05:37:38.3 +39:15:57 14.7 106 Positions are for J2000