Occultation event with (5144) Achates, event index number 784
Regions able to see the event: Europe
Geocentric closest approach at 2025/03/09 19:57:50 UTC
J2000 position of star is 01:26:18.6 +16:55:30
Equinox of date position of star is 01:27:39.9 +17:03:19
Star is 92 degrees from the moon. Moon is 81% illuminated.
Stellar brightness G=14.4, apparent brightess of occulting body is G=14.8
Use an exposure time of 0.50 seconds with the standard RECON-QHY system.
Expected flux drop is 41% with SNR of 9.8 per integration
Apparent velocity is 37.0 km/sec on the sky relative to the star, or, 32.0 arcsec/hr.
The recommended exposure time corresponds to 18.5 km per image.
The 1-sigma error in the time of the event is 0.9 seconds.
The 1-sigma cross-track error in the shadow position is 19.5 km.
The sky-plane scale is 4171.0 km/arcsec.
Diameter estimates:
86.7 km assuming a 5% albedo, aximum of 2.3 sec for a central chord
35.4 km assuming a 30% albedo, maximum of 1.0 sec for a central chord
Cross-track diameter of 86.7 km used for deployment plan.
Star training set for 5144_Achates, (2025/03/09 19:58UT) Object RA Dec mag sep mel Aldebaran 04:37:22.1 +16:33:28 0.8 45.29 50 6Bet Ari 01:56:02.2 +20:55:48 2.6 7.74 84 97 Psc 01:31:14.7 +18:29:06 6.0 1.66 90 PPM 117364 01:29:46.0 +17:12:31 7.0 0.53 91 PPM 117326 01:27:13.0 +17:04:13 9.2 0.11 92 PPM 117337 01:27:43.6 +17:07:38 10.1 0.07 91 5144_Achates 01:27:39.9 +17:03:19 14.8 91 Positions are for equinox of date
Star training set for 5144_Achates, (2025/03/09 19:58UT) Object RA Dec mag sep mel Aldebaran 04:35:55.3 +16:30:29 0.8 45.29 50 6Bet Ari 01:54:38.6 +20:48:26 2.6 7.74 84 97 Psc 01:29:53.0 +18:21:20 6.0 1.66 90 PPM 117364 01:28:24.6 +17:04:44 7.0 0.53 91 PPM 117326 01:25:51.7 +16:56:24 9.2 0.11 92 PPM 117337 01:26:22.3 +16:59:49 10.1 0.07 91 5144_Achates 01:26:18.6 +16:55:30 14.8 92 Positions are for J2000