Occultation event with (5144) Achates, event index number 4141
Regions able to see the event: Europe
Geocentric closest approach at 2026/09/01 01:13:16 UTC
J2000 position of star is 05:21:15.3 +31:22:12
Equinox of date position of star is 05:22:58.7 +31:23:40
Star is 55 degrees from the moon. Moon is 84% illuminated.
Stellar brightness G=14.5, apparent brightess of occulting body is G=15.5
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
SNR of 9.6 per integration for unocculted signal
Expected flux drop is 70% with SNR of 6.7 for the occulted depth (per occulted point)
Apparent velocity is 17.1 km/sec on the sky relative to the star, or, 13.8 arcsec/hr.
Position angle of asteroid motion is 74.9 degrees
The recommended exposure time corresponds to 8.5 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 27.4 km.
The sky-plane scale is 4455.3 km/arcsec.
Diameter estimates:
87.5 km assuming a 5% albedo, maximum of 5.1 sec for a central chord
35.7 km assuming a 30% albedo, maximum of 2.1 sec for a central chord
Cross-track diameter of 81.0 km used for deployment plan.
Star training set for 5144_Achates, (2026/09/01 01:13UT) Object RA Dec mag sep mel Aldebaran 04:37:27.2 +16:33:39 0.8 18.09 45 Alnath 05:27:58.8 +28:37:39 1.6 2.97 56 PPM 094297 05:22:54.6 +29:35:39 5.7 1.80 55 PPM 070258 05:23:52.7 +31:23:49 8.4 0.19 55 PPM 070241 05:23:13.7 +31:29:20 9.8 0.11 55 5144_Achates 05:22:58.7 +31:23:40 15.5 56 Positions are for equinox of date
Star training set for 5144_Achates, (2026/09/01 01:13UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 18.09 45 Alnath 05:26:17.6 +28:36:22 1.6 2.97 56 PPM 094297 05:21:12.7 +29:34:11 5.7 1.80 55 PPM 070258 05:22:09.2 +31:22:23 8.4 0.19 55 PPM 070241 05:21:30.2 +31:27:53 9.8 0.11 55 5144_Achates 05:21:15.3 +31:22:12 15.5 55 Positions are for J2000