Occultation event with (2223) Sarpedon, event index number 1320
Regions able to see the event: Europe
Geocentric closest approach at 2025/09/28 23:05:43 UTC
J2000 position of star is 03:30:21.9 +17:07:11
Equinox of date position of star is 03:31:49.5 +17:12:23
Star is 149 degrees from the moon. Moon is 40% illuminated.
Stellar brightness G=16.6, apparent brightess of occulting body is G=14.4
Use an exposure time of 2.00 seconds with the standard RECON-QHY system.
SNR of 3.6 per integration for unocculted signal
Expected flux drop is 13% with SNR of 0.5 for the occulted depth (per occulted point)
Apparent velocity is 8.8 km/sec on the sky relative to the star, or, 9.5 arcsec/hr.
Position angle of asteroid motion is 47.8 degrees
The recommended exposure time corresponds to 17.6 km per image.
The 1-sigma error in the time of the event is 3.1 seconds.
The 1-sigma cross-track error in the shadow position is 31.9 km.
The sky-plane scale is 3337.7 km/arcsec.
Diameter estimates:
90.4 km assuming a 5% albedo, aximum of 10.3 sec for a central chord
36.9 km assuming a 30% albedo, maximum of 4.2 sec for a central chord
Cross-track diameter of 77.5 km used for deployment plan.
Star training set for 2223_Sarpedon, (2025/09/28 23:06UT) Object RA Dec mag sep mel Aldebaran 04:37:24.1 +16:33:32 0.8 15.70 162 Menkar 03:03:37.7 +04:11:21 2.5 14.74 136 PPM 119253 03:40:53.4 +16:37:07 6.2 2.25 151 PPM 119121 03:31:10.0 +16:50:58 7.0 0.39 149 PPM 119151 03:33:08.2 +17:20:15 9.6 0.34 149 2223_Sarpedon 03:31:49.5 +17:12:23 14.4 150 Positions are for equinox of date
Star training set for 2223_Sarpedon, (2025/09/28 23:06UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 15.70 162 Menkar 03:02:16.8 +04:05:21 2.5 14.74 136 PPM 119253 03:39:25.8 +16:32:11 6.2 2.25 151 PPM 119121 03:29:42.6 +16:45:45 7.0 0.39 149 PPM 119151 03:31:40.5 +17:15:05 9.6 0.34 149 2223_Sarpedon 03:30:21.9 +17:07:11 14.4 149 Positions are for J2000