Occultation event with (15663) Periphas, event index number 3753
Regions able to see the event: SAmericaN
Geocentric closest approach at 2026/05/20 05:33:25 UTC
J2000 position of star is 12:12:03.2 -00:51:29
Equinox of date position of star is 12:13:24.4 -01:00:16
Star is 76 degrees from the moon. Moon is 17% illuminated.
Stellar brightness G=11.0, apparent brightess of occulting body is G=16.5
Use an exposure time of 0.12 seconds with the standard RECON-QHY system.
SNR of 36.5 per integration for unocculted signal
Expected flux drop is 99% with SNR of 36.3 for the occulted depth (per occulted point)
Apparent velocity is 9.7 km/sec on the sky relative to the star, or, 9.6 arcsec/hr.
Position angle of asteroid motion is 69.2 degrees
The recommended exposure time corresponds to 1.2 km per image.
The 1-sigma error in the time of the event is 2.1 seconds.
The 1-sigma cross-track error in the shadow position is 26.5 km.
The sky-plane scale is 3668.7 km/arcsec.
Diameter estimates:
40.7 km assuming a 5% albedo, maximum of 4.2 sec for a central chord
16.6 km assuming a 30% albedo, maximum of 1.7 sec for a central chord
Cross-track diameter of 36.2 km used for deployment plan.
Star training set for 15663_Periphas, (2026/05/20 05:33UT) Object RA Dec mag sep mel Spica 13:26:35.2 -11:17:53 1.0 20.88 97 Denebola 11:50:24.3 +14:25:28 2.1 16.45 64 13 Vir 12:20:01.5 -00:56:01 5.9 1.66 77 PPM 158596 12:12:46.5 +00:02:49 8.5 1.06 75 PPM 178712 12:13:22.9 -01:14:42 10.0 0.24 76 PPM 178718 12:14:18.6 -01:04:20 10.9 0.24 76 15663_Periphas 12:13:24.4 -01:00:16 16.5 76 Positions are for equinox of date
Star training set for 15663_Periphas, (2026/05/20 05:33UT) Object RA Dec mag sep mel Spica 13:25:11.5 -11:09:41 1.0 20.88 97 Denebola 11:49:02.7 +14:34:16 2.1 16.45 64 13 Vir 12:18:40.4 -00:47:14 5.9 1.66 77 PPM 158596 12:11:25.4 +00:11:37 8.5 1.06 75 PPM 178712 12:12:01.8 -01:05:54 10.0 0.24 76 PPM 178718 12:12:57.4 -00:55:32 10.9 0.24 76 15663_Periphas 12:12:03.2 -00:51:29 16.5 76 Positions are for J2000