Occultation event with (5144) Achates, event index number 4520
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/10/30 02:47:57 UTC
J2000 position of star is 05:24:50.3 +32:33:09
Equinox of date position of star is 05:26:35.5 +32:34:30
Star is 9 degrees from the moon. Moon is 80% illuminated.
Stellar brightness G=13.8, apparent brightess of occulting body is G=15.1
Use an exposure time of 0.25 seconds with the standard RECON-QHY system.
SNR of 9.9 per integration for unocculted signal
Expected flux drop is 76% with SNR of 7.5 for the occulted depth (per occulted point)
Apparent velocity is 11.0 km/sec on the sky relative to the star, or, 10.2 arcsec/hr.
Position angle of asteroid motion is 99.9 degrees
The recommended exposure time corresponds to 2.8 km per image.
The 1-sigma error in the time of the event is 0.5 seconds.
The 1-sigma cross-track error in the shadow position is 28.0 km.
The sky-plane scale is 3882.8 km/arcsec.
Diameter estimates:
87.5 km assuming a 5% albedo, maximum of 7.9 sec for a central chord
35.7 km assuming a 30% albedo, maximum of 3.2 sec for a central chord
Cross-track diameter of 81.0 km used for deployment plan.
Star training set for 5144_Achates, (2026/10/30 02:48UT) Object RA Dec mag sep mel Aldebaran 04:37:27.8 +16:33:40 0.8 19.49 23 Alnath 05:27:59.4 +28:37:39 1.6 3.96 8 25Chi Aur 05:34:28.6 +32:12:33 4.8 1.70 8 PPM 070293 05:25:45.8 +32:38:54 8.3 0.19 10 PPM 070312 05:26:32.0 +32:43:48 10.0 0.16 9 5144_Achates 05:26:35.5 +32:34:30 15.1 9 Positions are for equinox of date
Star training set for 5144_Achates, (2026/10/30 02:48UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 19.49 23 Alnath 05:26:17.6 +28:36:22 1.6 3.96 8 25Chi Aur 05:32:43.7 +32:11:31 4.8 1.70 8 PPM 070293 05:24:00.7 +32:37:32 8.3 0.19 10 PPM 070312 05:24:46.7 +32:42:27 10.0 0.16 9 5144_Achates 05:24:50.3 +32:33:09 15.1 9 Positions are for J2000