Occultation event with (3240) Laocoon, event index number 4057
Regions able to see the event: Australia
Geocentric closest approach at 2026/08/20 17:36:07 UTC
J2000 position of star is 04:51:14.8 +24:17:26
Equinox of date position of star is 04:52:52.1 +24:20:02
Star is 170 degrees from the moon. Moon is 56% illuminated.
Stellar brightness G=8.8, apparent brightess of occulting body is G=16.2
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 83.0 per integration for unocculted signal
Expected flux drop is 100% with SNR of 82.9 for the occulted depth (per occulted point)
Apparent velocity is 20.3 km/sec on the sky relative to the star, or, 18.0 arcsec/hr.
Position angle of asteroid motion is 81.8 degrees
The recommended exposure time corresponds to 2.4 km per image.
The 1-sigma error in the time of the event is 0.4 seconds.
The 1-sigma cross-track error in the shadow position is 33.2 km.
The sky-plane scale is 4054.7 km/arcsec.
Diameter estimates:
52.7 km assuming a 5% albedo, maximum of 2.6 sec for a central chord
21.5 km assuming a 30% albedo, maximum of 1.1 sec for a central chord
Cross-track diameter of 51.7 km used for deployment plan.
Star training set for 3240_Laocoon, (2026/08/20 17:36UT) Object RA Dec mag sep mel Aldebaran 04:37:27.1 +16:33:38 0.8 8.57 168 Alnath 05:27:58.7 +28:37:39 1.6 8.95 162 PPM 093742 04:47:19.2 +23:40:30 6.1 1.43 171 PPM 093877 04:56:14.7 +23:58:45 8.5 0.85 169 PPM 093822 04:52:52.2 +24:20:02 9.4 0.00 170 3240_Laocoon 04:52:52.1 +24:20:02 16.2 169 Positions are for equinox of date
Star training set for 3240_Laocoon, (2026/08/20 17:36UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 8.57 168 Alnath 05:26:17.6 +28:36:22 1.6 8.95 162 PPM 093742 04:45:42.5 +23:37:41 6.1 1.43 171 PPM 093877 04:54:37.6 +23:56:16 8.5 0.85 169 PPM 093822 04:51:14.9 +24:17:26 9.4 0.00 170 3240_Laocoon 04:51:14.8 +24:17:26 16.2 170 Positions are for J2000