Occultation event with (588) Achilles, event index number 3733
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/05/09 21:42:12 UTC
J2000 position of star is 12:24:03.7 -14:19:29
Equinox of date position of star is 12:25:25.7 -14:28:14
Star is 127 degrees from the moon. Moon is 50% illuminated.
Stellar brightness G=15.2, apparent brightess of occulting body is G=13.5
Use an exposure time of 2.00 seconds with the standard RECON-QHY system.
SNR of 9.2 per integration for unocculted signal
Expected flux drop is 17% with SNR of 1.6 for the occulted depth (per occulted point)
Apparent velocity is 11.1 km/sec on the sky relative to the star, or, 12.2 arcsec/hr.
Position angle of asteroid motion is 124.1 degrees
The recommended exposure time corresponds to 22.3 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 16.8 km.
The sky-plane scale is 3275.6 km/arcsec.
Diameter estimates:
136.1 km assuming a 5% albedo, maximum of 12.2 sec for a central chord
55.6 km assuming a 30% albedo, maximum of 5.0 sec for a central chord
Cross-track diameter of 130.1 km used for deployment plan.
Star training set for 588_Achilles, (2026/05/09 21:42UT) Object RA Dec mag sep mel Spica 13:26:35.1 -11:17:53 1.0 15.23 116 4Gam Crv 12:17:09.9 -17:41:17 2.6 3.78 127 PPM 225705 12:22:17.5 -13:42:42 5.1 1.07 128 PPM 225827 12:27:21.6 -15:05:37 7.1 0.78 126 PPM 225786 12:25:44.1 -14:35:51 9.4 0.15 127 588_Achilles 12:25:25.7 -14:28:14 13.5 127 Positions are for equinox of date
Star training set for 588_Achilles, (2026/05/09 21:42UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 15.23 116 4Gam Crv 12:15:48.1 -17:32:30 2.6 3.78 127 PPM 225705 12:20:55.7 -13:33:56 5.1 1.07 128 PPM 225827 12:25:59.4 -14:56:53 7.1 0.78 126 PPM 225786 12:24:22.1 -14:27:06 9.4 0.15 127 588_Achilles 12:24:03.7 -14:19:29 13.5 127 Positions are for J2000