Occultation event with (5144) Achates, event index number 1614
Regions able to see the event: Europe
Geocentric closest approach at 2025/11/29 21:43:35 UTC
J2000 position of star is 03:02:03.5 +28:23:25
Equinox of date position of star is 03:03:36.7 +28:29:28
Star is 54 degrees from the moon. Moon is 67% illuminated.
Stellar brightness G=14.7, apparent brightess of occulting body is G=14.4
Use an exposure time of 0.70 seconds with the standard RECON-QHY system.
SNR of 9.6 per integration for unocculted signal
Expected flux drop is 43% with SNR of 4.1 for the occulted depth (per occulted point)
Apparent velocity is 17.0 km/sec on the sky relative to the star, or, 18.4 arcsec/hr.
Position angle of asteroid motion is 67.9 degrees
The recommended exposure time corresponds to 11.9 km per image.
The 1-sigma error in the time of the event is 1.1 seconds.
The 1-sigma cross-track error in the shadow position is 23.4 km.
The sky-plane scale is 3332.7 km/arcsec.
Diameter estimates:
87.5 km assuming a 5% albedo, aximum 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, (2025/11/29 21:44UT) Object RA Dec mag sep mel Aldebaran 04:37:24.6 +16:33:33 0.8 24.66 72 44Zet Per 03:55:46.1 +31:57:30 2.8 11.78 65 PPM 092179 03:05:03.4 +28:22:12 6.5 0.34 54 PPM 092155 03:03:14.5 +28:37:11 11.3 0.15 54 5144_Achates 03:03:36.7 +28:29:28 14.4 54 Positions are for equinox of date
Star training set for 5144_Achates, (2025/11/29 21:44UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 24.66 72 44Zet Per 03:54:07.9 +31:53:01 2.8 11.78 65 PPM 092179 03:03:30.3 +28:16:11 6.5 0.34 54 PPM 092155 03:01:41.3 +28:31:08 11.3 0.15 54 5144_Achates 03:02:03.5 +28:23:25 14.4 54 Positions are for J2000