Occultation event with (2357) Phereclos, event index number 1227
Regions able to see the event: SAfrica
Geocentric closest approach at 2025/08/14 03:50:06 UTC
J2000 position of star is 03:15:58.2 +16:16:01
Equinox of date position of star is 03:17:24.6 +16:21:37
Star is 27 degrees from the moon. Moon is 73% illuminated.
Stellar brightness G=14.1, apparent brightess of occulting body is G=14.8
Use an exposure time of 0.35 seconds with the standard RECON-QHY system.
SNR of 10.0 per integration for unocculted signal
Expected flux drop is 65% with SNR of 6.5 for the occulted depth (per occulted point)
Apparent velocity is 11.9 km/sec on the sky relative to the star, or, 11.1 arcsec/hr.
Position angle of asteroid motion is 81.1 degrees
The recommended exposure time corresponds to 4.2 km per image.
The 1-sigma error in the time of the event is 1.0 seconds.
The 1-sigma cross-track error in the shadow position is 28.6 km.
The sky-plane scale is 3855.1 km/arcsec.
Diameter estimates:
95.9 km assuming a 5% albedo, aximum of 8.1 sec for a central chord
39.2 km assuming a 30% albedo, maximum of 3.3 sec for a central chord
Cross-track diameter of 94.6 km used for deployment plan.
Star training set for 2357_Phereclos, (2025/08/14 03:50UT) Object RA Dec mag sep mel Aldebaran 04:37:23.6 +16:33:31 0.8 19.17 46 Menkar 03:03:37.3 +04:11:19 2.5 12.63 25 57Del Ari 03:13:06.0 +19:49:19 4.3 3.61 27 PPM 118930 03:15:34.4 +15:41:03 7.2 0.81 27 PPM 118951 03:16:34.2 +16:23:47 8.9 0.20 27 2357_Phereclos 03:17:24.6 +16:21:37 14.8 27 Positions are for equinox of date
Star training set for 2357_Phereclos, (2025/08/14 03:50UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 19.17 46 Menkar 03:02:16.8 +04:05:21 2.5 12.63 25 57Del Ari 03:11:38.0 +19:43:36 4.3 3.61 27 PPM 118930 03:14:08.5 +15:35:25 7.2 0.81 27 PPM 118951 03:15:07.8 +16:18:10 8.9 0.20 27 2357_Phereclos 03:15:58.2 +16:16:01 14.8 27 Positions are for J2000