Occultation event with (2357) Phereclos, event index number 4278
Regions able to see the event: SAfrica
Geocentric closest approach at 2026/09/21 00:19:25 UTC
J2000 position of star is 05:22:40.5 +20:31:31
Equinox of date position of star is 05:24:15.9 +20:32:56
Star is 149 degrees from the moon. Moon is 70% illuminated.
Stellar brightness G=16.6, apparent brightess of occulting body is G=14.8
Use an exposure time of 2.00 seconds with the standard RECON-QHY system.
SNR of 3.6 per integration for unocculted signal
Expected flux drop is 15% with SNR of 0.6 for the occulted depth (per occulted point)
Apparent velocity is 8.5 km/sec on the sky relative to the star, or, 8.1 arcsec/hr.
Position angle of asteroid motion is 95.9 degrees
The recommended exposure time corresponds to 17.1 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 34.6 km.
The sky-plane scale is 3815.7 km/arcsec.
Diameter estimates:
95.9 km assuming a 5% albedo, maximum of 11.2 sec for a central chord
39.2 km assuming a 30% albedo, maximum of 4.6 sec for a central chord
Cross-track diameter of 94.6 km used for deployment plan.
Star training set for 2357_Phereclos, (2026/09/21 00:19UT) Object RA Dec mag sep mel Aldebaran 04:37:27.4 +16:33:39 0.8 11.78 137 Alnath 05:27:59.0 +28:37:39 1.6 8.12 151 PPM 120839 05:21:53.0 +19:36:11 6.5 1.10 148 PPM 094285 05:22:13.4 +20:51:17 8.0 0.57 149 PPM 094328 05:25:21.2 +20:36:07 9.0 0.26 149 2357_Phereclos 05:24:15.9 +20:32:56 14.8 150 Positions are for equinox of date
Star training set for 2357_Phereclos, (2026/09/21 00:19UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 11.78 137 Alnath 05:26:17.6 +28:36:22 1.6 8.12 151 PPM 120839 05:20:18.3 +19:34:41 6.5 1.10 148 PPM 094285 05:20:37.9 +20:49:48 8.0 0.57 149 PPM 094328 05:23:45.7 +20:34:45 9.0 0.26 149 2357_Phereclos 05:22:40.5 +20:31:31 14.8 149 Positions are for J2000