Occultation event with (5144) Achates, event index number 1489
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/11/11 04:57:29 UTC
J2000 position of star is 03:12:36.6 +29:09:31
Equinox of date position of star is 03:14:10.5 +29:15:15
Star is 73 degrees from the moon. Moon is 61% illuminated.
Stellar brightness G=15.1, apparent brightess of occulting body is G=14.2
Use an exposure time of 1.10 seconds with the standard RECON-QHY system.
SNR of 8.5 per integration for unocculted signal
Expected flux drop is 30% with SNR of 2.6 for the occulted depth (per occulted point)
Apparent velocity is 18.2 km/sec on the sky relative to the star, or, 19.9 arcsec/hr.
Position angle of asteroid motion is 75.2 degrees
The recommended exposure time corresponds to 20.0 km per image.
The 1-sigma error in the time of the event is 0.8 seconds.
The 1-sigma cross-track error in the shadow position is 25.7 km.
The sky-plane scale is 3283.1 km/arcsec.
Diameter estimates:
87.5 km assuming a 5% albedo, aximum of 4.8 sec for a central chord
35.7 km assuming a 30% albedo, maximum of 2.0 sec for a central chord
Cross-track diameter of 81.0 km used for deployment plan.
Star training set for 5144_Achates, (2025/11/11 04:57UT) Object RA Dec mag sep mel Aldebaran 04:37:24.5 +16:33:33 0.8 22.93 57 44Zet Per 03:55:45.9 +31:57:30 2.8 9.34 63 55 Ari 03:11:10.5 +29:10:27 5.7 0.66 73 PPM 092307 03:15:11.1 +29:19:38 8.3 0.23 72 5144_Achates 03:14:10.5 +29:15:15 14.2 72 Positions are for equinox of date
Star training set for 5144_Achates, (2025/11/11 04:57UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 22.93 57 44Zet Per 03:54:07.9 +31:53:01 2.8 9.34 63 55 Ari 03:09:36.8 +29:04:37 5.7 0.66 73 PPM 092307 03:13:37.0 +29:13:56 8.3 0.23 72 5144_Achates 03:12:36.6 +29:09:31 14.2 73 Positions are for J2000