Occultation event with (5144) Achates, event index number 5100
Regions able to see the event: Europe
Geocentric closest approach at 2026/12/07 19:26:59 UTC
J2000 position of star is 05:05:42.4 +32:30:54
Equinox of date position of star is 05:07:27.5 +32:32:59
Star is 163 degrees from the moon. Moon is 2% illuminated.
Stellar brightness G=14.5, apparent brightess of occulting body is G=14.7
Use an exposure time of 0.60 seconds with the standard RECON-QHY system.
SNR of 9.9 per integration for unocculted signal
Expected flux drop is 53% with SNR of 5.2 for the occulted depth (per occulted point)
Apparent velocity is 19.6 km/sec on the sky relative to the star, or, 18.9 arcsec/hr.
Position angle of asteroid motion is 83.0 degrees
The recommended exposure time corresponds to 11.8 km per image.
The 1-sigma error in the time of the event is 0.2 seconds.
The 1-sigma cross-track error in the shadow position is 28.5 km.
The sky-plane scale is 3738.3 km/arcsec.
Diameter estimates:
87.5 km assuming a 5% albedo, maximum of 4.5 sec for a central chord
35.7 km assuming a 30% albedo, maximum of 1.8 sec for a central chord
Cross-track diameter of 81.0 km used for deployment plan.
Star training set for 5144_Achates, (2026/12/07 19:27UT) Object RA Dec mag sep mel Aldebaran 04:37:28.2 +16:33:40 0.8 17.37 167 3Iot Aur 04:58:45.1 +33:12:22 2.7 1.94 165 14 Aur 05:17:09.8 +32:42:58 5.2 2.05 161 PPM 069989 05:11:50.0 +31:57:43 8.2 1.10 163 PPM 069905 05:07:18.0 +32:34:06 9.8 0.04 163 5144_Achates 05:07:27.5 +32:32:59 14.7 163 Positions are for equinox of date
Star training set for 5144_Achates, (2026/12/07 19:27UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 17.37 167 3Iot Aur 04:56:59.6 +33:09:57 2.7 1.94 165 14 Aur 05:15:24.3 +32:41:15 5.2 2.05 161 PPM 069989 05:10:05.3 +31:55:49 8.2 1.10 163 PPM 069905 05:05:32.8 +32:32:01 9.8 0.04 163 5144_Achates 05:05:42.4 +32:30:54 14.7 163 Positions are for J2000