Occultation event with (2357) Phereclos, event index number 1383
Regions able to see the event: SAmericaN
Geocentric closest approach at 2025/10/17 23:56:32 UTC
J2000 position of star is 03:11:06.1 +15:24:07
Equinox of date position of star is 03:12:32.5 +15:29:53
Star is 116 degrees from the moon. Moon is 11% illuminated.
Stellar brightness G=14.8, apparent brightess of occulting body is G=14.1
Use an exposure time of 0.90 seconds with the standard RECON-QHY system.
SNR of 9.8 per integration for unocculted signal
Expected flux drop is 36% with SNR of 3.5 for the occulted depth (per occulted point)
Apparent velocity is 14.8 km/sec on the sky relative to the star, or, 16.3 arcsec/hr.
Position angle of asteroid motion is 71.2 degrees
The recommended exposure time corresponds to 13.4 km per image.
The 1-sigma error in the time of the event is 1.1 seconds.
The 1-sigma cross-track error in the shadow position is 26.5 km.
The sky-plane scale is 3271.7 km/arcsec.
Diameter estimates:
95.9 km assuming a 5% albedo, aximum of 6.5 sec for a central chord
39.2 km assuming a 30% albedo, maximum of 2.6 sec for a central chord
Cross-track diameter of 94.6 km used for deployment plan.
Star training set for 2357_Phereclos, (2025/10/17 23:57UT) Object RA Dec mag sep mel Aldebaran 04:37:24.2 +16:33:32 0.8 20.41 96 Menkar 03:03:37.9 +04:11:22 2.5 11.52 120 PPM 118814 03:07:48.9 +13:17:07 5.6 2.49 118 PPM 118850 03:10:10.7 +15:25:51 8.5 0.57 117 PPM 118887 03:12:14.6 +15:28:09 8.6 0.08 116 2357_Phereclos 03:12:32.5 +15:29:53 14.1 116 Positions are for equinox of date
Star training set for 2357_Phereclos, (2025/10/17 23:57UT) Object RA Dec mag sep mel Aldebaran 04:35:55.4 +16:30:29 0.8 20.41 96 Menkar 03:02:16.8 +04:05:21 2.5 11.52 120 PPM 118814 03:06:23.7 +13:11:13 5.6 2.49 118 PPM 118850 03:08:44.4 +15:20:01 8.5 0.57 117 PPM 118887 03:10:48.2 +15:22:22 8.6 0.08 116 2357_Phereclos 03:11:06.1 +15:24:07 14.1 116 Positions are for J2000