Occultation event with (5144) Achates, event index number 1448
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/11/03 02:58:37 UTC
J2000 position of star is 03:17:19.7 +29:24:05
Equinox of date position of star is 03:18:54.0 +29:29:41
Star is 48 degrees from the moon. Moon is 91% illuminated.
Stellar brightness G=16.3, apparent brightess of occulting body is G=14.3
Use an exposure time of 1.15 seconds with the standard RECON-QHY system.
SNR of 3.3 per integration for unocculted signal
Expected flux drop is 14% with SNR of 0.5 for the occulted depth (per occulted point)
Apparent velocity is 17.5 km/sec on the sky relative to the star, or, 19.2 arcsec/hr.
Position angle of asteroid motion is 78.3 degrees
The recommended exposure time corresponds to 20.1 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 26.5 km.
The sky-plane scale is 3285.9 km/arcsec.
Diameter estimates:
87.5 km assuming a 5% albedo, aximum of 5.0 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, (2025/11/03 02:59UT) Object RA Dec mag sep mel Aldebaran 04:37:24.4 +16:33:33 0.8 22.16 63 44Zet Per 03:55:45.8 +31:57:29 2.8 8.29 57 PPM 092402 03:21:54.6 +29:08:25 4.5 0.75 49 PPM 092351 03:18:37.6 +28:51:09 7.7 0.64 48 PPM 092365 03:19:28.7 +29:32:21 9.6 0.13 48 5144_Achates 03:18:54.0 +29:29:41 14.3 49 Positions are for equinox of date
Star training set for 5144_Achates, (2025/11/03 02:59UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 22.16 63 44Zet Per 03:54:07.9 +31:53:01 2.8 8.29 57 PPM 092402 03:20:20.3 +29:02:54 4.5 0.75 49 PPM 092351 03:17:03.7 +28:45:32 7.7 0.64 48 PPM 092365 03:17:54.4 +29:26:46 9.6 0.13 48 5144_Achates 03:17:19.7 +29:24:05 14.3 48 Positions are for J2000